Plant root systems,a crucial component of biogeotechnics,have been recognized as a promising and sustainable strategy to address novel challenges in geotechnical engineering,i.e.,climate change(Ng et al.,2022).Root-so...Plant root systems,a crucial component of biogeotechnics,have been recognized as a promising and sustainable strategy to address novel challenges in geotechnical engineering,i.e.,climate change(Ng et al.,2022).Root-soil composite and root-reinforced slopes have re-ceived widespread attention in recent decades,due to the ability of root to regulate soil properties through mechanical reinforcement and hy-draulic transpiration(Li&Duan,2023;Ni et al.,2024).Fig.1 provides a co-occurrence network plot of plant root-based soil reinforcement strategies published over the last decade,where three clusters are identified with different colors.On the left of the network map,clusters in red and blue are primarily driven by geotechnical investigations of vegetated slopes(i.e.,plant root reinforced slopes)and root-soil com-posite/root-permeated soils,as denoted by the terms like"model","test","slope","strength"and"vegetation",while the green cluster on the right side demonstrates botany-related domains,for instance,"plant growth",Indeed,the reinforcement of vegetated soil strength is com-plex and varies significantly with an abundance of factors,both me-chanically and hydraulically.Particularly,the impact of root mor-phology and architecture cannot be negligible,including keywords"root area ratio"root distribution""root morphology"root diame-ter"root density"in Fig.1 with the root size and root depth ranking foremost.展开更多
With the objective of investigating the basis of phosphorus(P)utilization efficiency(PUE),physiological and morphological traits,two P-efficient and two P-inefficient rapeseed(Brassica napus L.)cultivars were compared...With the objective of investigating the basis of phosphorus(P)utilization efficiency(PUE),physiological and morphological traits,two P-efficient and two P-inefficient rapeseed(Brassica napus L.)cultivars were compared at the seedling stage.P-efficient cultivars showed root morphological adaptation,high P uptake activity,and greater phospholipid degradation under low P stress.Improving root morphological adaptation and reducing lipid-P allocation could allow increasing PUE in rapeseed seedlings.展开更多
Root morphology in plants may be related to phosphorus (P) efficiency by affecting the absorption characteristics of the root system. However, genotypic variation in root morphological characteristics of common bean (...Root morphology in plants may be related to phosphorus (P) efficiency by affecting the absorption characteristics of the root system. However, genotypic variation in root morphological characteristics of common bean ( Phaseolus vulgaris L.) as affected by P availability has not been well clarified. In the present study, systematic studies were conducted in a P-buffered sand culture system using three pairs of common bean parental materials with contrasting root traits in response to P deficiency. The results indicate that P availability significantly affects bean root morphology. Common bean tends to have smaller root system, shorter and coarser roots at low P availability. Genotypic variation in root morphology was observed among different genotypes in response to P availability. The P efficient genotypes appear to have larger, finer and longer root systems than the P inefficient genotypes, and such a variation was particularly obvious in the basal roots. From allomeric analysis, we found that morphological characteristics of the basal roots contribute more to P efficiency than those of the tap roots. Further studies with the F-9 recombinant inbred lines derived from one of the most contrasting parental pairs, DOR364 and G19833, confirmed the above findings, indicating that those morphological characteristics are inheritable hence provide potential for genetic improvement.展开更多
[Objective] The aim was to explore biomass and growth of Cupressus lusitanica seedlings in order to provide technological supports for afforestation. [Method] The introduced Cupressus lusitanica seedlings at different...[Objective] The aim was to explore biomass and growth of Cupressus lusitanica seedlings in order to provide technological supports for afforestation. [Method] The introduced Cupressus lusitanica seedlings at different ages were re- searched to explore biomass （ground or underground） morphological shape, surface area and volume of a root system. [Result] As age grew, plant height and ground diameter increased significantly, varying dramatically upon seed provenance, and root-canopy ratio, root length, surface area and volume of seedlings were increas- ing. Specifically, seedlings at two-year-old and three-year-old kept a stable growth; moderate and big roots took higher proportions in a root system; underground parts for a plant required more photosynthetic products; root systems of young seedlings grew to moderate and big roots. [Conclusion] Ground biomass is of correlation with root system indices and the morphological characteristics of root systems are close to biomass. The accumulation capacity of biomass differed for seedlings from differ- ent provenances, even in the same environment and at the same time.展开更多
Research on root morphological traits of dry-raised seedlings (D-RS) at different growth stages of rice have so far attracted less attention. In this study, using mid-season indica hy-
This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam.and Lolium perenne L.exposed to two C...This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam.and Lolium perenne L.exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0,4,and 16 mg/L) under hydroponic conditions.The results show that elevated levels of CO2 increased shoot biomass more,compared to root biomass,but decreased Cd concentrations in all plant tissues.Cd exposure caused toxicity to both Lolium species,as shown by the restrictions of the root morphological parameters including root length,surface area,volume,and tip numbers.These parameters were significantly higher under elevated levels of CO2 than under ambient CO2,especially for the number of fine roots.The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress,suggesting an ameliorated Cd stress under elevated levels of CO2.The total Cd uptake per pot,calculated on the basis of biomass,was significantly greater under elevated levels of CO2 than under ambient CO2.Ameliorated Cd toxicity,decreased Cd concentration,and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation.展开更多
Four different ratios of river sand,ceramic pellets,vermiculite and perlite(1:1),and field soil were selected as the substrates in this experiment,and four gradient levels of root waterlogging,half waterlogging,full w...Four different ratios of river sand,ceramic pellets,vermiculite and perlite(1:1),and field soil were selected as the substrates in this experiment,and four gradient levels of root waterlogging,half waterlogging,full waterlogging and normal were set to investigate the effects of different gradients of waterlogging stress on the root morphology of Taxus chinensis var.mairei seedlings under different substrates.In this study,the root anatomical structure of Taxus chinensis var.mairei under different waterlogging stress was observed by the paraffin section method.The roots of T.chinensis var.mairei were diarch,with no pith and resin canals.There was a large number of tannins in the pericycle of the aerial adventitious roots of seedlings adapted to waterlogging.Also,the endodermis has obvious casparian strip thickening,and there were 4-5 layers of large parenchymatous cells in the close to the inner side of the pericycle in the vascular cylinder,which could increase the storage capacity,and transport capacity of the root.Under the treatment of root waterlogging stress,the development of plant roots in the mixed substrate of vermiculite and,perlite was the earliest.Under half waterlogging stress,T.chinensis var.mairei seedlings treated with various substrates all could better adapt to the environment of waterlogging stress.Under the stress of fully waterlogging,the roots of seedlings planted in river sand substrate developed secondary growth.展开更多
Two field experiments with different soybean (Glycine max L.) materials were conducted to investigate the interactions between phosphorus (P) and nitrogen (N) as related to the genetic attributes of root morphological...Two field experiments with different soybean (Glycine max L.) materials were conducted to investigate the interactions between phosphorus (P) and nitrogen (N) as related to the genetic attributes of root morphological and nodular traits. In experiment one, 13 cultivated soybean varieties were grown in a field with relatively low soil P and N availability. P application with 160 kg P/hm2 as triple superphosphate produced a significant simultaneous increase in the content of both P and N in shoot, demonstrating positive P and N interactions. The addition of P also increased root dry weight, root nodule number, nodule mass, nodule size, and nodulation index, but decreased root length and root surface area, indicating that P may affect N nutrition in soybean through a number of root morphological and nodular traits. Interestingly, like P content, N content appeared to be more correlated with root morphological traits (root weight, root length, and root surface area) than with root nodular traits (nodule number, nodule size, nodule mass, and nodulation index) at both P levels, implying that N taken up by the roots may contribute more to the plant N status than biological N2 fixation under the present experimental conditions. In experiment two, 57 soybean lines of a recombinant inbred line (RIL) population derived from a cross between a cultivated variety and a wild genotype were grown on another field site with moderately sufficient P and N levels to further characterize the genetic attributes of root morphological and nodular traits and their relationships with P and N interactions. The results indicated that all morphological and nodular traits measured continually segregated in the RIL population with a normal distribution of the phenotypic values, indicating that these traits are possibly controlled by quantitative trait loci (QTLs). Genetic analysis revealed that all these root traits had relatively low heritabilities (h2b=74.12,70.65,73.76,56.34,52.59, and 52.24 for root weight, root length, root surface area, nodule number, nodule mass, and nodule size, respectively), suggesting that root morphology and nodule formation are influenced greatly by environmental factors. Correlation analysis of the RILs showed that shoot N content was significantly correlated with P content, confirming positive PXN interactions. Similar to experiment one, shoot N content was only significantly correlated with root morphological traits, but not with root nodular traits, again denoting the fact that the N status in soybean could be attributed more to N uptake from the soil than to biological N2 fixation under the present experimental conditions.展开更多
Nitrogen(N)fixation by legumes and nitrogen transfer to cereals have been considered as important pathways for overyielding and higher N use efficiency in cereal/legume intercropping systems.However,the extent to whic...Nitrogen(N)fixation by legumes and nitrogen transfer to cereals have been considered as important pathways for overyielding and higher N use efficiency in cereal/legume intercropping systems.However,the extent to which root morphology contributes to N fixation and transfer is unclear.A two-factorial greenhouse experiment was conducted to quantify the N fixation,transfer and root morphology characteristics of the maize/alfalfa intercropping system in two consecutive years using the 15N-urea leaf labeling method,and combining two N levels with three root separation techniques.N application could inhibit N fixation and transfer in a maize/alfalfa intercropping system.Irrespective of the N application level,compared with plastic sheet separation(PSS),no separation(NS)and nylon mesh separation(NNS)significantly increased the total biomass(36%)and total N content(28%),while the N fixation rate also sharply increased by 75 to 134%,and the amount of N transferred with no root barrier was 1.24–1.42 times greater than that with a mesh barrier.Redundancy analysis(RDA)showed that the crown root dry weight(CRDW)of maize and lateral root number(LRN)of alfalfa showed the strongest associations with N fixation and transfer.Our results highlight the importance of root contact for the enhancement of N fixation and transfer via changes in root morphology in maize/alfalfa intercropping systems,and the overyielding system was achieved via increases in maize growth,at the cost of smaller decreases in alfalfa biomass production.展开更多
The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiolo...The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiological role of endogenous hormones in regulating root-crown interactions in the short term.The morphological characteristics and endogenous hormone contents of normal roots(no root cutting,CK)and cut roots(cut by 1/3 of the length of the main root,RP)were determined by liquid chromatography,which was combined with mass spectrometry at different levels of different developmental stages.The results showed that the root growth indexes and root endogenous hormones in the RP group were superior to those in the CK group.Through comprehensive analysis of endogenous hormones,it was found that the crosstalk of IAA,JA,ABA and SA could activate the root growth defense.After the root cutting treatment,the root growth of Quercus variabilis seedlings could compensate for the inhibition of taproot growth by promoting lateral root growth.The growth and development of compensatory lateral roots contribute to the increase the total root length of plants,thus promoting the absorption of water and nutrients.It is speculated that plant hormones may be the key factors affecting their development,but this is not only related to the content of a single hormone,but more importantly,it is the interaction between various hormones.展开更多
[Objective] The aim was to investigate different effects of two pH-regulating acids on the root morphology and other physiological growth of Lactuca sativa L.in floating plug transplant system.[Method] HNO3 and H2SO4 ...[Objective] The aim was to investigate different effects of two pH-regulating acids on the root morphology and other physiological growth of Lactuca sativa L.in floating plug transplant system.[Method] HNO3 and H2SO4 were used to adjust pH condition of various nutrient concentrations in lettuce floating transplant system,the effect of two acid treatments on root traits of lettuce were investigated.[Result] These two acids made different effects on root system under a series of nutrient gradients.Under HNO3 treatment,the fresh weight of shoot and root were increased with growth of nutrient concentration;root preformed best when EC was 1.0 μs/cm.Under H2SO4 treatment,when EC was 0.8 μs/cm,the total root length and root surface area,projected area,root volume of lettuce were 344.8 cm,40.9 cm2,13.0 cm2,0.4 m3,respectively,which were significantly higher than those in HNO3 treatment.Compared the influences of acid treatments under same nutrient concentration,the result showed that H2SO4 treatment increased root/shoot ratio and all other root morphological characteristics;however,HNO3 treatment promoted the growth of shoot and lateral root,increased transplanting efficiency and facilitated realizing high yield after transplanted into open-field.[Conclusion] This study will provide theoretical reference for improving plug transplant technology of lettuce.展开更多
A solution culture experiment was performed to investigate the effects of oxytetracycline （OTC） on wheat （Triticum aestivum L.） growth, chlorophyll contents, and photosynthesis at five levels of 0, 10, 20, 40, and...A solution culture experiment was performed to investigate the effects of oxytetracycline （OTC） on wheat （Triticum aestivum L.） growth, chlorophyll contents, and photosynthesis at five levels of 0, 10, 20, 40, and 80 mmol L-1 OTC. OTC is toxic to wheat. The wheat growth, especially wheat root was significantly decreased. Further OTC also significantly decreased root activity, chlorophyll contents, and photosynthetic parameters except for intercellular CO2 concentrations. The different responses of indicators such as root number, root activity and so on to OTC were also observed. The IC50 values for the tested indicators to OTC ranged from 7.1 to 113.4 mmol L-1 OTC. The order of indicator sensitivity to OTC was root number stomatal conductance chlorophyll a total chlorophyll photosynthetic rates total surface area transpiration rate chlorophyll b fresh weight of root dry weight of root total length dry weight of shoot = fresh weight of shoot total volume. The root number was more sensitive than other indicators with the IC50 value of 7.1 mmol L-1 OTC, and could be taken as the sensitive indicator to predict the hazards of OTC to wheat.展开更多
Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- t...Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- tribution of one-year-old A. sparsifolia seedlings to different groundwater depths in controlled plots. The eco- logical adaptability of the root systems of A. sparsifolia seedlings was examined using the artificial digging method. Results showed that： （1） A. sparsifolia seedlings adapted to an increase in groundwater depth mainly through increasing the penetration depth and growth rate of vertical roots. The vertical roots grew rapidly when soil moisture content reached 3%-9%, but slowly when soil moisture content was 13%-20%. The vertical roots stopped growing when soil moisture content reached 30% （the critical soil moisture point）. （2） The morphological plasticity of roots is an important strategy used by A. sparsifolia seedlings to obtain water and adapt to dry soil conditions. When the groundwater table was shallow, horizontal roots quickly expanded and tillering increased in order to compete for light resources, whereas when the groundwater table was deeper, vertical roots developed quickly to exploit space in the deeper soil layers. （3） The decrease in groundwater depth was probably respon- sible for the root distribution in the shallow soil layers. Root biomass and surface area both decreased with soil depth. One strategy of A. sparsifolia seedlings in dealing with the increase in groundwater depth is to increase root biomass in the deep soil layers. The relationship between the root growth/distribution of A. sparsifolia and the depth of groundwater table can be used as guidance for harvesting A. sparsifolia biomass and managing water resources for forage grasses. It is also of ecological significance as it reveals how desert plants adapt to arid environments.展开更多
In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale ...In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area.Through experiments and numerical simulations,plant roots characteristics,soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed,and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed.The results show that the highest soil moisture infiltration capacity(FIR)is found on the shady slope of the enclosed grassland(2.25),followed by the sunny slope of the enclosed grassland(1.23)and the shady slope of the naturally grazed grassland(-0.87).Correlation analysis show that soil water content,root dry weight density,total soil porosity,number of forks and root length are positively correlated with infiltration rate(P<0.05),whereas soil dry density is negatively correlated with infiltration rate(P<0.05).The results of stepwise regression analyses show that soil water content,total soil porosity,root length and number of forks are the main factors affecting soil infiltration capacity.And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself.After 60 min of simulated rainfall,the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56%and 19.63%,respectively,comparing to those before rainfall.Therefore,in this study,the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content,soil total porosity and shear strength while decreasing soil dry density.The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.展开更多
Root system is a vital part of plant and regulates many aspects of shoot growth and development. This paper reviews how some traits of root morphology and physiology are related to the formation of grain yield in rice...Root system is a vital part of plant and regulates many aspects of shoot growth and development. This paper reviews how some traits of root morphology and physiology are related to the formation of grain yield in rice （Oryza sativa L.）. Higher root biomass, root oxidation activity, and cytokinin contents in roots are required for achieving more panicle number, more spikelets per panicle, greater grain-filling percentage, and higher grain yield. However, these root traits are not linearly correlated with yield components. When these traits reach very high levels, grain filling and grain yield are not necessarily enhanced. High numbers of mitochondria, Golgi bodies, and amyloplasts in root tip cells benefit root and shoot growth and yield formation. Proper crop management, such as an alternate wetting and moderate soil drying irrigation, can significantly improve ultra-structure of root tip cells, increase root length density and concentration of cytokinins in root bleedings, and consequently, increase grain-filling percentage, grain yield, and water use efficiency. Further studies are needed to investigate the mechanism underlying root-shoot and root-soil interactions for high grain yield, the roles of root-sourced hormones in regulating crop growth and development and the effects of soil moisture and nutrient management on the root architecture and physiology.展开更多
Potassium （K） deficiency is one of the major abiotic stresses which has drastically influenced maize growth and yield around the world. However, the physiological mechanism of K deficiency tolerance is not yet fully...Potassium （K） deficiency is one of the major abiotic stresses which has drastically influenced maize growth and yield around the world. However, the physiological mechanism of K deficiency tolerance is not yet fully understood. To identify the differences of root morphology, physiology and endogenous hormones at different growing stages, two maize inbred lines 90-21-3 （tolerance to K deficiency） and D937 （sensitive to K deficiency） were cultivated in the long-term K fertilizer experimental pool under high potassium （＋K） and low potassium （-K） treatments. The results indicated that the root length, volume and surface area of 90-21-3 were significantly higher than those of D937 under -K treatment at different growing stages. It was noteworthy that the lateral roots of 90-21-3 were dramatically higher than those of D937 at tasselling and flowering stage under-K treatment. Meanwhile, the values of superoxide dismutase （SOD） and oxidizing force of 90-21-3 were apparently higher than those of D937, whereas malondialdehyde （MDA） content of D937 was obviously increased. Compared with ＋K treatment, the indole-3-acetic acid （IAA） content of 90-21-3 was largely increased under-K treatment, whereas it was sharply decreased in D937. On the contrary, abscisic acid （ABA） content of 90-21-3 was slightly increased, but that of D937 was significantly increased. The zeatin riboside （ZR） content of 90-21-3 was significantly decreased, while that of D937 was relatively increased. These results indicated that the endogenous hormones were stimulated in 90-21-3 to adjust lateral root development and to maintain the physiology function thereby alleviating K deficiency.展开更多
The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 ...The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 mmol L^-1） and three NO^-3 levels （0.05, 5, and 10 mmol L^-1） in solution culture for 30 d. Addition of NO^-3 at 10 mmol L^-1 significantly improved the shoot （P 〈 0.001） and root （P 〈 0.001） growth and the promotive effect of NO^-3 was more pronounced on root dry weight despite the high NaCl concentration in the culture solution, leading to a significant increase in the root：shoot ratio （P 〈 0.01）. Lateral root length, but not primary root length, considerably increased with increasing NaCl salinity and NO^-3 levels （P 〈 0.001）, implying that Na^＋ and NO3^- in the culture solution simultaneously stimulated lateral root growth. Concentrations of Na^＋ in plant tissues were also significantly increased by higher NaCl treatments （P 〈 0.001）. At 10 mmol L^-1 NO^-3, the concentrations of NO^-3 and total nitrogen and nitrate reductase activities in the roots were remarkably reduced by increasing salinity （P 〈 0.001）, but were unaffected in the shoots. The results indicated that the fine lateral root development and effective nitrogen uptake of the shoots might contribute to high salt tolerance of S. physophora under adequate NO^-3 supply.展开更多
Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinf...Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinforcement is not fully understood.In this study,the influence of soil moisture on root pullout properties was studied by experiments.Vertical in-situ pullout tests under four different levels of soil matric suction(12 kPa,18 kPa,24 kPa,30 kPa)were carried out on roots of sea buckthorn plants(Hippophae rhamnoides Linn.)which were artificially cultivated for 7 months.Diameter and length of the root system of sea buckthorn were investigated.The results showed that a very significant correlation was observed between root diameter(D)and root length(L)(P<0.01),and root diameter decreased with soil depth.When soil bulk density was constant,peak pullout force(F)and friction coefficient of root-soil interface(μ)decreased with increasing gravimetric soil moisture content in power functions.Soil moisture content significantly affected root pullout resistance because the increase of soil moisture content decreased the friction coefficient between the roots and soil.Root diameter at breakage point(Db)and length of root segment left in soil(Lb)were increased with soil moisture content.In addition,peak pullout force of the roots increased in a power function with root diameter at the soil surface(D0)and in a linear function with total root length(L).The results provided an experimental basis for quantifying the effects of soil moisture content on soil reinforcement by plant roots.展开更多
Root morphology and physiology influence aboveground growth and yield formation in rice.However,root morphological and physiological differences among rice varieties with differing nitrogen(N)sensitivities and their r...Root morphology and physiology influence aboveground growth and yield formation in rice.However,root morphological and physiological differences among rice varieties with differing nitrogen(N)sensitivities and their relationship with grain yield are still unclear.In this study,rice varieties differing in N sensitivity over many years of experiments were used.A field experiment with multiple N rates(0,90,180,270,and 360 kg ha^(-1))was conducted to elucidate the effects of N application on root morphology,root physiology,and grain yield.A pot experiment with root excision and exogenous application of 6-benzyladenine(6-BA)at heading stage was used to further verify the above effects.The findings revealed that(1)under the same N application rate,N-insensitive varieties(NIV)had relatively large root biomass(root dry weight,length,and number).Grain yield was associated with root biomass in NIV.The oxidation activity and zeatin(Z)+zeatin riboside(ZR)contents in roots obviously and positively correlated with grain yield in N-sensitive varieties(NSV),and accounted for its higher grain yield than that of NIV at lower N application rates(90 and 180 kg ha^(-1)).(2)The root dry weight required for equal grain yield of NIV was greater than that of NSV.Excision of 1/10 and 1/8 of roots at heading stage had no discernible effect on the yield of Liangyoupeijiu(NIV),and it significantly reduced yield by 11.5%and 21.3%in Tianyouhuazhan(NSV),respectively,compared to the treatment without root excision.The decrease of filled kernels and grain weight after root excision was the primary cause for the yield reduction.Root excision and exogenous 6-BA application after root excision had little influence on the root activity of NIV.The oxidation activity and Z+ZR contents in roots of NSV decreased under root excision,and the increase in the proportion of excised roots aggravated these effects.The application of exogenous 6-BA increased the root activity of NSV and increased filled kernels and grain weight,thereby reducing yield loss after root excision.Thus,the root biomass of NIV was large,and there may be a phenomenon of"root growth redundancy."Vigorous root activity was an essential feature of NSV.Selecting rice varieties with high root activity or increasing root activity by cultivation measures could lead to higher grain yield under lower N application rates.展开更多
Elsholtzia argyi and Elsholtzia splendens, which are Chinese endemic Pb/Zn mined and Cu mined ecotype respec- tively, were investigated on the aspect of their response to Pb toxicity in the presence or absence of EDTA...Elsholtzia argyi and Elsholtzia splendens, which are Chinese endemic Pb/Zn mined and Cu mined ecotype respec- tively, were investigated on the aspect of their response to Pb toxicity in the presence or absence of EDTA addition. After 8 d’s Pb treatment, root length, root surface area and root volume of E. splendens decreased much more than those of E. argyi, and reduced considerably with increase of Pb, while no marked change was noted for root average diameter. Compared to E. argyi, length of root with diameter (D)<0.2 mm was significantly reduced for E. splendens as Pb increased. D<0.1 mm E. splendens root had cross-sectional surface area at Pb≥10 mg/L, while for E. argyi, it was at Pb≥25 mg/L. With increase of Pb, DW of E. splendens decreased much more than that of E. argyi. E. argyi exhibited much more tolerance to Pb toxicity than E. splendens. Treatment with 100 mg/L Pb plus 50 mmol/L EDTA significantly decreased the length and surface area of D≤0.2 mm root, increased the length and surface area of 0.2≤D≤0.8 mm root for the case of E. argyi, while for E. splendens, length and surface area of D<0.6 mm root reduced, as compared to 100 mg/L Pb treatment, alone. At 100 mg/L Pb, shoot Pb accumulation in E. splendens and E. argyi were 27.9 and 89.0 μg/plant DW respectively, and much more Pb was uptaken by the root and translocated to the stem of E. argyi as compared to E. splendens. Treatment of the plant with 100 mg/L Pb plus 50 mmol/L EDTA increased leaf Pb accumulation from 16.8 to 84.9 g/plant for E.splendens and from 18.8 to 52.5 g/plant for E. argyi, while both root and stem Pb pronouncedly reduced for both Elsholtzia species. The increased translocation of Pb to the leaf of E. splendens being than that of E. argyi after treatment with 100 mg/L Pb plus 50 mmol/L EDTA should be further investigated.展开更多
基金supported by Natural Science Foundation of Chongqing(No.CSTB2022NSCQ-LZX0001)High-end Foreign Expert Introduction program(No.G2022165004L)+1 种基金High-end Foreign Expert Introduction program(No.DL2021165001L)The fi-nancial supports are gratefully acknowledged.
文摘Plant root systems,a crucial component of biogeotechnics,have been recognized as a promising and sustainable strategy to address novel challenges in geotechnical engineering,i.e.,climate change(Ng et al.,2022).Root-soil composite and root-reinforced slopes have re-ceived widespread attention in recent decades,due to the ability of root to regulate soil properties through mechanical reinforcement and hy-draulic transpiration(Li&Duan,2023;Ni et al.,2024).Fig.1 provides a co-occurrence network plot of plant root-based soil reinforcement strategies published over the last decade,where three clusters are identified with different colors.On the left of the network map,clusters in red and blue are primarily driven by geotechnical investigations of vegetated slopes(i.e.,plant root reinforced slopes)and root-soil com-posite/root-permeated soils,as denoted by the terms like"model","test","slope","strength"and"vegetation",while the green cluster on the right side demonstrates botany-related domains,for instance,"plant growth",Indeed,the reinforcement of vegetated soil strength is com-plex and varies significantly with an abundance of factors,both me-chanically and hydraulically.Particularly,the impact of root mor-phology and architecture cannot be negligible,including keywords"root area ratio"root distribution""root morphology"root diame-ter"root density"in Fig.1 with the root size and root depth ranking foremost.
基金supported by the National Key Research and Development Program of China(2024YFD2301200)National Nature Science Foundation of China(32172662).
文摘With the objective of investigating the basis of phosphorus(P)utilization efficiency(PUE),physiological and morphological traits,two P-efficient and two P-inefficient rapeseed(Brassica napus L.)cultivars were compared at the seedling stage.P-efficient cultivars showed root morphological adaptation,high P uptake activity,and greater phospholipid degradation under low P stress.Improving root morphological adaptation and reducing lipid-P allocation could allow increasing PUE in rapeseed seedlings.
文摘Root morphology in plants may be related to phosphorus (P) efficiency by affecting the absorption characteristics of the root system. However, genotypic variation in root morphological characteristics of common bean ( Phaseolus vulgaris L.) as affected by P availability has not been well clarified. In the present study, systematic studies were conducted in a P-buffered sand culture system using three pairs of common bean parental materials with contrasting root traits in response to P deficiency. The results indicate that P availability significantly affects bean root morphology. Common bean tends to have smaller root system, shorter and coarser roots at low P availability. Genotypic variation in root morphology was observed among different genotypes in response to P availability. The P efficient genotypes appear to have larger, finer and longer root systems than the P inefficient genotypes, and such a variation was particularly obvious in the basal roots. From allomeric analysis, we found that morphological characteristics of the basal roots contribute more to P efficiency than those of the tap roots. Further studies with the F-9 recombinant inbred lines derived from one of the most contrasting parental pairs, DOR364 and G19833, confirmed the above findings, indicating that those morphological characteristics are inheritable hence provide potential for genetic improvement.
基金Supported by National Program "948"(2009-4-17)~~
文摘[Objective] The aim was to explore biomass and growth of Cupressus lusitanica seedlings in order to provide technological supports for afforestation. [Method] The introduced Cupressus lusitanica seedlings at different ages were re- searched to explore biomass （ground or underground） morphological shape, surface area and volume of a root system. [Result] As age grew, plant height and ground diameter increased significantly, varying dramatically upon seed provenance, and root-canopy ratio, root length, surface area and volume of seedlings were increas- ing. Specifically, seedlings at two-year-old and three-year-old kept a stable growth; moderate and big roots took higher proportions in a root system; underground parts for a plant required more photosynthetic products; root systems of young seedlings grew to moderate and big roots. [Conclusion] Ground biomass is of correlation with root system indices and the morphological characteristics of root systems are close to biomass. The accumulation capacity of biomass differed for seedlings from differ- ent provenances, even in the same environment and at the same time.
文摘Research on root morphological traits of dry-raised seedlings (D-RS) at different growth stages of rice have so far attracted less attention. In this study, using mid-season indica hy-
基金Project supported by the Central Public Research Institute Basic Fund for Research and Development (2008-jxh-1),Agro-environmental Protection Institute,Ministry of Agriculture,China
文摘This study was conducted to investigate the combined effects of elevated CO2 levels and cadmium (Cd) on the root morphological traits and Cd accumulation in Lolium multiflorum Lam.and Lolium perenne L.exposed to two CO2 levels (360 and 1000 μl/L) and three Cd levels (0,4,and 16 mg/L) under hydroponic conditions.The results show that elevated levels of CO2 increased shoot biomass more,compared to root biomass,but decreased Cd concentrations in all plant tissues.Cd exposure caused toxicity to both Lolium species,as shown by the restrictions of the root morphological parameters including root length,surface area,volume,and tip numbers.These parameters were significantly higher under elevated levels of CO2 than under ambient CO2,especially for the number of fine roots.The increases in magnitudes of those parameters triggered by elevated levels of CO2 under Cd stress were more than those under non-Cd stress,suggesting an ameliorated Cd stress under elevated levels of CO2.The total Cd uptake per pot,calculated on the basis of biomass,was significantly greater under elevated levels of CO2 than under ambient CO2.Ameliorated Cd toxicity,decreased Cd concentration,and altered root morphological traits in both Lolium species under elevated levels of CO2 may have implications in food safety and phytoremediation.
基金This work was supported by the National Natural Science Foundation of China[Grant No.31270740].
文摘Four different ratios of river sand,ceramic pellets,vermiculite and perlite(1:1),and field soil were selected as the substrates in this experiment,and four gradient levels of root waterlogging,half waterlogging,full waterlogging and normal were set to investigate the effects of different gradients of waterlogging stress on the root morphology of Taxus chinensis var.mairei seedlings under different substrates.In this study,the root anatomical structure of Taxus chinensis var.mairei under different waterlogging stress was observed by the paraffin section method.The roots of T.chinensis var.mairei were diarch,with no pith and resin canals.There was a large number of tannins in the pericycle of the aerial adventitious roots of seedlings adapted to waterlogging.Also,the endodermis has obvious casparian strip thickening,and there were 4-5 layers of large parenchymatous cells in the close to the inner side of the pericycle in the vascular cylinder,which could increase the storage capacity,and transport capacity of the root.Under the treatment of root waterlogging stress,the development of plant roots in the mixed substrate of vermiculite and,perlite was the earliest.Under half waterlogging stress,T.chinensis var.mairei seedlings treated with various substrates all could better adapt to the environment of waterlogging stress.Under the stress of fully waterlogging,the roots of seedlings planted in river sand substrate developed secondary growth.
基金the McKnight Foundation Collaborative Crop Research Program，国家自然科学基金，国家重点基础研究发展计划(973计划)
文摘Two field experiments with different soybean (Glycine max L.) materials were conducted to investigate the interactions between phosphorus (P) and nitrogen (N) as related to the genetic attributes of root morphological and nodular traits. In experiment one, 13 cultivated soybean varieties were grown in a field with relatively low soil P and N availability. P application with 160 kg P/hm2 as triple superphosphate produced a significant simultaneous increase in the content of both P and N in shoot, demonstrating positive P and N interactions. The addition of P also increased root dry weight, root nodule number, nodule mass, nodule size, and nodulation index, but decreased root length and root surface area, indicating that P may affect N nutrition in soybean through a number of root morphological and nodular traits. Interestingly, like P content, N content appeared to be more correlated with root morphological traits (root weight, root length, and root surface area) than with root nodular traits (nodule number, nodule size, nodule mass, and nodulation index) at both P levels, implying that N taken up by the roots may contribute more to the plant N status than biological N2 fixation under the present experimental conditions. In experiment two, 57 soybean lines of a recombinant inbred line (RIL) population derived from a cross between a cultivated variety and a wild genotype were grown on another field site with moderately sufficient P and N levels to further characterize the genetic attributes of root morphological and nodular traits and their relationships with P and N interactions. The results indicated that all morphological and nodular traits measured continually segregated in the RIL population with a normal distribution of the phenotypic values, indicating that these traits are possibly controlled by quantitative trait loci (QTLs). Genetic analysis revealed that all these root traits had relatively low heritabilities (h2b=74.12,70.65,73.76,56.34,52.59, and 52.24 for root weight, root length, root surface area, nodule number, nodule mass, and nodule size, respectively), suggesting that root morphology and nodule formation are influenced greatly by environmental factors. Correlation analysis of the RILs showed that shoot N content was significantly correlated with P content, confirming positive PXN interactions. Similar to experiment one, shoot N content was only significantly correlated with root morphological traits, but not with root nodular traits, again denoting the fact that the N status in soybean could be attributed more to N uptake from the soil than to biological N2 fixation under the present experimental conditions.
基金This study was financially supported by the National Natural Science Foundation of China(31471945)。
文摘Nitrogen(N)fixation by legumes and nitrogen transfer to cereals have been considered as important pathways for overyielding and higher N use efficiency in cereal/legume intercropping systems.However,the extent to which root morphology contributes to N fixation and transfer is unclear.A two-factorial greenhouse experiment was conducted to quantify the N fixation,transfer and root morphology characteristics of the maize/alfalfa intercropping system in two consecutive years using the 15N-urea leaf labeling method,and combining two N levels with three root separation techniques.N application could inhibit N fixation and transfer in a maize/alfalfa intercropping system.Irrespective of the N application level,compared with plastic sheet separation(PSS),no separation(NS)and nylon mesh separation(NNS)significantly increased the total biomass(36%)and total N content(28%),while the N fixation rate also sharply increased by 75 to 134%,and the amount of N transferred with no root barrier was 1.24–1.42 times greater than that with a mesh barrier.Redundancy analysis(RDA)showed that the crown root dry weight(CRDW)of maize and lateral root number(LRN)of alfalfa showed the strongest associations with N fixation and transfer.Our results highlight the importance of root contact for the enhancement of N fixation and transfer via changes in root morphology in maize/alfalfa intercropping systems,and the overyielding system was achieved via increases in maize growth,at the cost of smaller decreases in alfalfa biomass production.
基金funded by National Natural Science Foundation of China,Grant Number 31700549China Postdoctoral Science Foundation Project,Grant Number 2017M612401.
文摘The objective of this study was to investigate the effects of root cutting stress on the dynamic changes of endogenous hormone content and growth characteristics of Quercus variabilis roots,and to explore the physiological role of endogenous hormones in regulating root-crown interactions in the short term.The morphological characteristics and endogenous hormone contents of normal roots(no root cutting,CK)and cut roots(cut by 1/3 of the length of the main root,RP)were determined by liquid chromatography,which was combined with mass spectrometry at different levels of different developmental stages.The results showed that the root growth indexes and root endogenous hormones in the RP group were superior to those in the CK group.Through comprehensive analysis of endogenous hormones,it was found that the crosstalk of IAA,JA,ABA and SA could activate the root growth defense.After the root cutting treatment,the root growth of Quercus variabilis seedlings could compensate for the inhibition of taproot growth by promoting lateral root growth.The growth and development of compensatory lateral roots contribute to the increase the total root length of plants,thus promoting the absorption of water and nutrients.It is speculated that plant hormones may be the key factors affecting their development,but this is not only related to the content of a single hormone,but more importantly,it is the interaction between various hormones.
基金Supported by Special Fund for Guangdong Modern Agriculture Industrial System Construction (Guangdong Agriculture 2009-380 )Key Agriculture Project of Guangdong Science and Technology Department (2009B020202003 )+1 种基金Key Agriculture Project of Guangdong Science and Technology Department (2009B020304002)Agriculture Brainstorm Project of Panyu District Guangzhou,Guangdong Province (2010-Z-82-1)~~
文摘[Objective] The aim was to investigate different effects of two pH-regulating acids on the root morphology and other physiological growth of Lactuca sativa L.in floating plug transplant system.[Method] HNO3 and H2SO4 were used to adjust pH condition of various nutrient concentrations in lettuce floating transplant system,the effect of two acid treatments on root traits of lettuce were investigated.[Result] These two acids made different effects on root system under a series of nutrient gradients.Under HNO3 treatment,the fresh weight of shoot and root were increased with growth of nutrient concentration;root preformed best when EC was 1.0 μs/cm.Under H2SO4 treatment,when EC was 0.8 μs/cm,the total root length and root surface area,projected area,root volume of lettuce were 344.8 cm,40.9 cm2,13.0 cm2,0.4 m3,respectively,which were significantly higher than those in HNO3 treatment.Compared the influences of acid treatments under same nutrient concentration,the result showed that H2SO4 treatment increased root/shoot ratio and all other root morphological characteristics;however,HNO3 treatment promoted the growth of shoot and lateral root,increased transplanting efficiency and facilitated realizing high yield after transplanted into open-field.[Conclusion] This study will provide theoretical reference for improving plug transplant technology of lettuce.
基金supported by the National Natural Science Foundation of China (40701163)the Natural Science Foundation of Beijing City, China (6092019)+1 种基金the International Foundation for Science, Stockholm, Sweden, the Organization for the Prohibition of Chemical Weapons, the Hague, and the Netherlands, through a grant to Li Zhaojun (C/4076)the National Basic Research Program of China (973 Program, 2007CB109305)
文摘A solution culture experiment was performed to investigate the effects of oxytetracycline （OTC） on wheat （Triticum aestivum L.） growth, chlorophyll contents, and photosynthesis at five levels of 0, 10, 20, 40, and 80 mmol L-1 OTC. OTC is toxic to wheat. The wheat growth, especially wheat root was significantly decreased. Further OTC also significantly decreased root activity, chlorophyll contents, and photosynthetic parameters except for intercellular CO2 concentrations. The different responses of indicators such as root number, root activity and so on to OTC were also observed. The IC50 values for the tested indicators to OTC ranged from 7.1 to 113.4 mmol L-1 OTC. The order of indicator sensitivity to OTC was root number stomatal conductance chlorophyll a total chlorophyll photosynthetic rates total surface area transpiration rate chlorophyll b fresh weight of root dry weight of root total length dry weight of shoot = fresh weight of shoot total volume. The root number was more sensitive than other indicators with the IC50 value of 7.1 mmol L-1 OTC, and could be taken as the sensitive indicator to predict the hazards of OTC to wheat.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-316)the National Natural Science Foundation of China (31070477,30870471)the West Light Foundation of the Chinese Academy of Sciences (XBBS201105)
文摘Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- tribution of one-year-old A. sparsifolia seedlings to different groundwater depths in controlled plots. The eco- logical adaptability of the root systems of A. sparsifolia seedlings was examined using the artificial digging method. Results showed that： （1） A. sparsifolia seedlings adapted to an increase in groundwater depth mainly through increasing the penetration depth and growth rate of vertical roots. The vertical roots grew rapidly when soil moisture content reached 3%-9%, but slowly when soil moisture content was 13%-20%. The vertical roots stopped growing when soil moisture content reached 30% （the critical soil moisture point）. （2） The morphological plasticity of roots is an important strategy used by A. sparsifolia seedlings to obtain water and adapt to dry soil conditions. When the groundwater table was shallow, horizontal roots quickly expanded and tillering increased in order to compete for light resources, whereas when the groundwater table was deeper, vertical roots developed quickly to exploit space in the deeper soil layers. （3） The decrease in groundwater depth was probably respon- sible for the root distribution in the shallow soil layers. Root biomass and surface area both decreased with soil depth. One strategy of A. sparsifolia seedlings in dealing with the increase in groundwater depth is to increase root biomass in the deep soil layers. The relationship between the root growth/distribution of A. sparsifolia and the depth of groundwater table can be used as guidance for harvesting A. sparsifolia biomass and managing water resources for forage grasses. It is also of ecological significance as it reveals how desert plants adapt to arid environments.
基金supported by the National Natural Science Foundation of China(42041006)the Natural Science Foundation of Qinghai Province(2020-ZJ-906).
文摘In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River,this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area.Through experiments and numerical simulations,plant roots characteristics,soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed,and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed.The results show that the highest soil moisture infiltration capacity(FIR)is found on the shady slope of the enclosed grassland(2.25),followed by the sunny slope of the enclosed grassland(1.23)and the shady slope of the naturally grazed grassland(-0.87).Correlation analysis show that soil water content,root dry weight density,total soil porosity,number of forks and root length are positively correlated with infiltration rate(P<0.05),whereas soil dry density is negatively correlated with infiltration rate(P<0.05).The results of stepwise regression analyses show that soil water content,total soil porosity,root length and number of forks are the main factors affecting soil infiltration capacity.And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself.After 60 min of simulated rainfall,the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56%and 19.63%,respectively,comparing to those before rainfall.Therefore,in this study,the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content,soil total porosity and shear strength while decreasing soil dry density.The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.
基金supported by the National Natural Science Foundation of China (31061140457, 31071360)the National Basic Research Program of China (2009CB118603)+3 种基金the Natural Science Foundation of Jiangsu Province, China(BK2009-005)the Key Technologies R&D Program of Chinaduring the 12th Five-Year Plan period (2011BAD16B14)the Program of Advantage Discipline of Jiangsu Provincethe Hong Kong Research Grants Council, China (HKBU262809)
文摘Root system is a vital part of plant and regulates many aspects of shoot growth and development. This paper reviews how some traits of root morphology and physiology are related to the formation of grain yield in rice （Oryza sativa L.）. Higher root biomass, root oxidation activity, and cytokinin contents in roots are required for achieving more panicle number, more spikelets per panicle, greater grain-filling percentage, and higher grain yield. However, these root traits are not linearly correlated with yield components. When these traits reach very high levels, grain filling and grain yield are not necessarily enhanced. High numbers of mitochondria, Golgi bodies, and amyloplasts in root tip cells benefit root and shoot growth and yield formation. Proper crop management, such as an alternate wetting and moderate soil drying irrigation, can significantly improve ultra-structure of root tip cells, increase root length density and concentration of cytokinins in root bleedings, and consequently, increase grain-filling percentage, grain yield, and water use efficiency. Further studies are needed to investigate the mechanism underlying root-shoot and root-soil interactions for high grain yield, the roles of root-sourced hormones in regulating crop growth and development and the effects of soil moisture and nutrient management on the root architecture and physiology.
基金supported by the Program for Liaoning Excellent Talents in University, China (LR2013032)the National Natural Science Foundation of China (31301259, 31101106)the Tianzhu Mountian Scholars Support Plan of Shenyang Agricultural University, China
文摘Potassium （K） deficiency is one of the major abiotic stresses which has drastically influenced maize growth and yield around the world. However, the physiological mechanism of K deficiency tolerance is not yet fully understood. To identify the differences of root morphology, physiology and endogenous hormones at different growing stages, two maize inbred lines 90-21-3 （tolerance to K deficiency） and D937 （sensitive to K deficiency） were cultivated in the long-term K fertilizer experimental pool under high potassium （＋K） and low potassium （-K） treatments. The results indicated that the root length, volume and surface area of 90-21-3 were significantly higher than those of D937 under -K treatment at different growing stages. It was noteworthy that the lateral roots of 90-21-3 were dramatically higher than those of D937 at tasselling and flowering stage under-K treatment. Meanwhile, the values of superoxide dismutase （SOD） and oxidizing force of 90-21-3 were apparently higher than those of D937, whereas malondialdehyde （MDA） content of D937 was obviously increased. Compared with ＋K treatment, the indole-3-acetic acid （IAA） content of 90-21-3 was largely increased under-K treatment, whereas it was sharply decreased in D937. On the contrary, abscisic acid （ABA） content of 90-21-3 was slightly increased, but that of D937 was significantly increased. The zeatin riboside （ZR） content of 90-21-3 was significantly decreased, while that of D937 was relatively increased. These results indicated that the endogenous hormones were stimulated in 90-21-3 to adjust lateral root development and to maintain the physiology function thereby alleviating K deficiency.
基金Supported by the Key Technology Program of the Xinjiang Uygur Autonomous Region, China (No.200733144-1)the Knowledge Innovation Project of the Chinese of Academy of Sciences (No.KSCX2-YW-N-41)
文摘The effects of NaCl salinity and NO^-3 on growth, root morphology, and nitrogen uptake of a halophyte Suaeda physophora were evaluated in a factorial experiment with four concentrations of NaCl （1, 150, 300, and 450 mmol L^-1） and three NO^-3 levels （0.05, 5, and 10 mmol L^-1） in solution culture for 30 d. Addition of NO^-3 at 10 mmol L^-1 significantly improved the shoot （P 〈 0.001） and root （P 〈 0.001） growth and the promotive effect of NO^-3 was more pronounced on root dry weight despite the high NaCl concentration in the culture solution, leading to a significant increase in the root：shoot ratio （P 〈 0.01）. Lateral root length, but not primary root length, considerably increased with increasing NaCl salinity and NO^-3 levels （P 〈 0.001）, implying that Na^＋ and NO3^- in the culture solution simultaneously stimulated lateral root growth. Concentrations of Na^＋ in plant tissues were also significantly increased by higher NaCl treatments （P 〈 0.001）. At 10 mmol L^-1 NO^-3, the concentrations of NO^-3 and total nitrogen and nitrate reductase activities in the roots were remarkably reduced by increasing salinity （P 〈 0.001）, but were unaffected in the shoots. The results indicated that the fine lateral root development and effective nitrogen uptake of the shoots might contribute to high salt tolerance of S. physophora under adequate NO^-3 supply.
基金supported by the National Natural Science Foundation of China project(No.31600582)Research Project Supported by Shanxi Scholarship Council of China(2020-054)+1 种基金Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi Province of China(2017)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2019L0175)。
文摘Plant root system plays an important role in preventing soil erosion and improving slope stability.However,its performance is significantly affected by soil moisture content,and the role of soil moisture in root reinforcement is not fully understood.In this study,the influence of soil moisture on root pullout properties was studied by experiments.Vertical in-situ pullout tests under four different levels of soil matric suction(12 kPa,18 kPa,24 kPa,30 kPa)were carried out on roots of sea buckthorn plants(Hippophae rhamnoides Linn.)which were artificially cultivated for 7 months.Diameter and length of the root system of sea buckthorn were investigated.The results showed that a very significant correlation was observed between root diameter(D)and root length(L)(P<0.01),and root diameter decreased with soil depth.When soil bulk density was constant,peak pullout force(F)and friction coefficient of root-soil interface(μ)decreased with increasing gravimetric soil moisture content in power functions.Soil moisture content significantly affected root pullout resistance because the increase of soil moisture content decreased the friction coefficient between the roots and soil.Root diameter at breakage point(Db)and length of root segment left in soil(Lb)were increased with soil moisture content.In addition,peak pullout force of the roots increased in a power function with root diameter at the soil surface(D0)and in a linear function with total root length(L).The results provided an experimental basis for quantifying the effects of soil moisture content on soil reinforcement by plant roots.
基金the National Natural Science Foundation of China(32071947,32071944,31871557)the Open Project of Jiangsu Key Laboratory of Crop Genetics and Physiology(YCSL202102)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Postgraduate Research&Practice Innovation Program of Jiangsu province(KYCX21_3235).
文摘Root morphology and physiology influence aboveground growth and yield formation in rice.However,root morphological and physiological differences among rice varieties with differing nitrogen(N)sensitivities and their relationship with grain yield are still unclear.In this study,rice varieties differing in N sensitivity over many years of experiments were used.A field experiment with multiple N rates(0,90,180,270,and 360 kg ha^(-1))was conducted to elucidate the effects of N application on root morphology,root physiology,and grain yield.A pot experiment with root excision and exogenous application of 6-benzyladenine(6-BA)at heading stage was used to further verify the above effects.The findings revealed that(1)under the same N application rate,N-insensitive varieties(NIV)had relatively large root biomass(root dry weight,length,and number).Grain yield was associated with root biomass in NIV.The oxidation activity and zeatin(Z)+zeatin riboside(ZR)contents in roots obviously and positively correlated with grain yield in N-sensitive varieties(NSV),and accounted for its higher grain yield than that of NIV at lower N application rates(90 and 180 kg ha^(-1)).(2)The root dry weight required for equal grain yield of NIV was greater than that of NSV.Excision of 1/10 and 1/8 of roots at heading stage had no discernible effect on the yield of Liangyoupeijiu(NIV),and it significantly reduced yield by 11.5%and 21.3%in Tianyouhuazhan(NSV),respectively,compared to the treatment without root excision.The decrease of filled kernels and grain weight after root excision was the primary cause for the yield reduction.Root excision and exogenous 6-BA application after root excision had little influence on the root activity of NIV.The oxidation activity and Z+ZR contents in roots of NSV decreased under root excision,and the increase in the proportion of excised roots aggravated these effects.The application of exogenous 6-BA increased the root activity of NSV and increased filled kernels and grain weight,thereby reducing yield loss after root excision.Thus,the root biomass of NIV was large,and there may be a phenomenon of"root growth redundancy."Vigorous root activity was an essential feature of NSV.Selecting rice varieties with high root activity or increasing root activity by cultivation measures could lead to higher grain yield under lower N application rates.
基金Project supported by the National Basic Research Program (973)(No. 2002CB410804) of China and the National Natural ScienceFoundation of China (No. 20307008)
文摘Elsholtzia argyi and Elsholtzia splendens, which are Chinese endemic Pb/Zn mined and Cu mined ecotype respec- tively, were investigated on the aspect of their response to Pb toxicity in the presence or absence of EDTA addition. After 8 d’s Pb treatment, root length, root surface area and root volume of E. splendens decreased much more than those of E. argyi, and reduced considerably with increase of Pb, while no marked change was noted for root average diameter. Compared to E. argyi, length of root with diameter (D)<0.2 mm was significantly reduced for E. splendens as Pb increased. D<0.1 mm E. splendens root had cross-sectional surface area at Pb≥10 mg/L, while for E. argyi, it was at Pb≥25 mg/L. With increase of Pb, DW of E. splendens decreased much more than that of E. argyi. E. argyi exhibited much more tolerance to Pb toxicity than E. splendens. Treatment with 100 mg/L Pb plus 50 mmol/L EDTA significantly decreased the length and surface area of D≤0.2 mm root, increased the length and surface area of 0.2≤D≤0.8 mm root for the case of E. argyi, while for E. splendens, length and surface area of D<0.6 mm root reduced, as compared to 100 mg/L Pb treatment, alone. At 100 mg/L Pb, shoot Pb accumulation in E. splendens and E. argyi were 27.9 and 89.0 μg/plant DW respectively, and much more Pb was uptaken by the root and translocated to the stem of E. argyi as compared to E. splendens. Treatment of the plant with 100 mg/L Pb plus 50 mmol/L EDTA increased leaf Pb accumulation from 16.8 to 84.9 g/plant for E.splendens and from 18.8 to 52.5 g/plant for E. argyi, while both root and stem Pb pronouncedly reduced for both Elsholtzia species. The increased translocation of Pb to the leaf of E. splendens being than that of E. argyi after treatment with 100 mg/L Pb plus 50 mmol/L EDTA should be further investigated.
