Internode number and length are the foundation to constitute plant height, ear height and the above-ground spatial structure of maize plant. In this study, segregating populations were constructed between EHel with ex...Internode number and length are the foundation to constitute plant height, ear height and the above-ground spatial structure of maize plant. In this study, segregating populations were constructed between EHel with extremely low ear height and B73. Through the SNP-based genotyping and phenotypic characterization, 13 QTL distributed on the chromosomes (Chrs) of Chr1, Chr2, Chr5-Chr8 were detected for four traits of internode no. above ear (INa), average internode length above ear (ILaa), internode no. below ear (INb), and average internode length below ear (ILab). Phenotypic variation explained (PVE) by a single QTL ranged from 6.82% (qILab2-2) to 12.99% (qILaa5). Zm00001d016823 within the physical region of qILaa5, the major QTL for ILaa with the largest PVE was determined as the candidate through the genomic annotation and sequence alignment between EHel and B73. Product of Zm00001d016823 was annotated as a WEB family protein homogenous to At1g75720. qRT-PCR assay showed that Zm00001d016823 highly expressed within the tissue of internode, exhibiting statistically higher expression levels among internodes of IN4 to IN7 in EHel than those in B73 (P Zm00001d016823 might provide novel insight into molecular mechanism beyond phytohormones controlling internode development in maize.展开更多
The occurrence of high temperature(HT)in crop production is becoming more frequent and unpredictable with global warming,severely threatening food security.The state of an organ’s growth and development is largely de...The occurrence of high temperature(HT)in crop production is becoming more frequent and unpredictable with global warming,severely threatening food security.The state of an organ’s growth and development is largely determined by the temperature conditions it is exposed to over time.Maize is the main cereal crop,and its stem growth and plant architecture are closely related to lodging resistance,and especially sensitive to temperature.However,systematic research on the timing effect of HT on the sequentially developing internode and stem is currently lacking.To identify the timing effect of HT on the morphology and plasticity of the stem in maize,two hybrids(Zhengdan 958(ZD958),Xianyu 335(XY335))characterized by distinct morphological traits in the stem were exposed to a 7-day HT treatment from the V6 to V17 stages(Vn presents the vegetative stage with n leaves fully expanded)in 2019-2020.The results demonstrated that exposure to HT during V6-V12 accelerated the rapid elongation of stems.For instance,HT occurring at V7 and V12 specifically promoted the lengths and weights of the 3rd-5th and 9th-11th internodes,respectively.Meanwhile,HT slowed the growth of internodes adjacent to the promoted internodes.Interestingly,compared with control,the plant height was significantly increased soon after HT treatment,but the promotion effect became narrower at the subsequent flowering stage,demonstrating a self-adjusting mechanism in the maize plant in response to HT.Importantly,HT altered the plant architectures,including a rising of the ear position and increase in the ear position coefficient.XY335 exhibited greater sensitivity in stem development than ZD958 under HT treatment.These findings improve our systematic understanding of the plasticity of internode and plant architecture in response to the timing of HT exposure.展开更多
[Objective] This study aimed to investigate the genetic effects and heterosis of plant height and internode traits of japonica-indica hybrid rice. [Methed] Incomplete diallel crosses were made between six japonica CMS...[Objective] This study aimed to investigate the genetic effects and heterosis of plant height and internode traits of japonica-indica hybrid rice. [Methed] Incomplete diallel crosses were made between six japonica CMS lines and nine indica widecompatibility restorer lines; the genetic effects of plant height and internode traits of japonica-indica hybrid rice were analyzed using the additive-dominance genetic model. [Result] The ple, nt height, panicle length and the length of internode 1 of japonica-in- dica hybrid rice were mainly controlled by the additive effects; but the length of in- ternode 3, internode 4 and internode 5 were mainly controlled by dominance effects. Both the narrow sense heritability and broad sense heritability of plant height, panicle length, number of elongated internodes and length of most internodes reached signifi- cance level. The positive phenotypic correlation, genetic correlation, additive correla- tion and dominance correlation between plant height and panicle length, number of e- longated internodes and internode length were significant; and most of the other paired traits were significantly positively correlated. Heterosis analysis showed that the positive heterosis value over mid-parent and positive heterosis value over better- parent of the length of internode 3, internode 4, internode 5 and internode 6 reached significant level, and the heterosis value over mid-parent of plant height reached extreme significance level. [Conclusion] This study will provide reliable theoretical basis for the genetic improvement and heterosis utilization of plant height and internode traits in japonica-indica hybrid rice.展开更多
We analyzed the relationship between internode number and intemode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubes...We analyzed the relationship between internode number and intemode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubescens, the intemode number was assigned from base to tip and the length for each internode was directly measured. The result indicated that the intemode length should be cumulated from base to tip, and then the cumulated internode length should be relativized by the total culm length. It was inappropriate to relativize the internode length by the maximum intenode length. In addition, the relationship between the relative internode number （the intemode number relativized by the total number of intemodes） and the relative cumulated internode length should be described not by a power function but by a sigmoid function such as the third-order function. The determined function enabled us to estimate the actual internode length, with the root mean squared error being 4 cm. In conclusion, the mathematical expression presented here, i.e., the relativization of the cumulated internode length by the total culm length and the application of the sigmoid function, will be useful in describing the relationship between internode number and internode length for P. pubescens.展开更多
Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role ...Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.展开更多
Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of bas...Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.展开更多
A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville,FL, USA to investigate how a soybean(Glycine max L. Merr.) cultivar, Maverick(maturity group III, indeterminate), responded to th...A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville,FL, USA to investigate how a soybean(Glycine max L. Merr.) cultivar, Maverick(maturity group III, indeterminate), responded to three elevated temperatures, ELT,(day/night of 34/26 °C, 38/30 °C, and 42/34 °C) in comparison to a control growth temperature(30/22 °C).Carbon dioxide(CO_2) concentration was maintained at 700 μmol mol^(-1) in each compartment by a processor controlled air-sampling and CO_2-injection system. Three sequential experiments were conducted at different times of year(summer, autumn, and early spring)to investigate the effect of intensity, timing, and duration of ELT on soybean node number,internode elongation, mainstem length, and number of pods set per plant. At the control temperature, the soybean plants grown in the polycarbonate greenhouse were taller than field-grown plants. When plants were grown under continuous ELT applied soon after sowing or at initial flowering, the number of nodes increased with increasing ELT intensity,whereas the length of individual internodes decreased. When ELT treatment was applied during the beginning of flowering stage(R1–R2) or earlier, more nodes were produced and the length of affected internodes was decreased. When the ELT was imposed later at reproductive stage R5+ just before the beginning of seed filling, effects on node numbers and internode lengths were negligible. Short-term(10-day) duration of ELT applied at four stages from V3 to R5+ did not significantly affect final mean numbers of nodes or mean mainstem lengths. Possible mechanisms of elevated temperature effects on soybean internode elongation and node number(internode number) are discussed. Total pod numbers per plant increased linearly with mainstem node numbers and mainstem length.Furthermore, total pod numbers per plant were greatest at 34/26 °C rather than at the control temperature of 30/22 °C(and remained high at 38/30 °C). Mild increases in temperature might not threaten, but actually increase, yields of soybean in northerly zones where this crop is currently grown at slightly suboptimal temperatures. However, a sustained increase in ambient temperature would likely threaten soybean yields.展开更多
The characteristics of vascular bundle in the first internode from top and grain-filling of heavy panicle type hybrid rice(HPTHR) were studied. The results were as follows: The HPTHR had more vascular bundles and a mu...The characteristics of vascular bundle in the first internode from top and grain-filling of heavy panicle type hybrid rice(HPTHR) were studied. The results were as follows: The HPTHR had more vascular bundles and a much bigger area of single vascular bundle, all vascular bundle, all phloem and all xylem in the first inter-node than Shanyou63. The vascular bundles had the similar load of spikelet number and sink capacity between the HPTHR and Shanyou63. The HPTHR had not only a larger sink but also normal grain-filling and sink-filling, high seed-setting rate and heavier panicle. Those characteristics of vascular bundle were the biological bases for the larger and heavier panicle of HPTHR. The results also indicated that the breeding model of HPTHR was an effective measure for the super high-yielding rice breeding.展开更多
Changxuan 3S, a thermo-sensitive genic male sterile （TGMS） rice line with eui gene, is derived from the TGMS rice line Pei＇ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elo...Changxuan 3S, a thermo-sensitive genic male sterile （TGMS） rice line with eui gene, is derived from the TGMS rice line Pei＇ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elongation of the TGMS line with eui gene, Changxuan 3S and its parent Pei＇ai 64S were used to study the effects of temperature on panicle exsertion. At 24℃, the uppermost internode of Changxuan 3S elongated the fastest from the 4^th day before flowering to 0 day （flowering）, being 2.1-fold as that of Pei＇ai 64S, whereas it elongated slowly during the 12^th day to the 4^th day before flowering and the 1^st to the 3^rd day after flowering. The uppermost internode of Changxuan 3S exserted from the flag leaf sheath at 22℃, 24℃ and 26℃, and the length of elongated uppermost internode increased with the decreasing temperatures. At 28℃, though the panicles of Changxuan 3S were still enclosed in the leaf sheath, the degree of panicle enclosure was significantly lower compared with Pei＇ai 64S. Cytological studies on Changxuan 3S showed that the uppermost internode elongation was attributed to the increase of cell number and cell elongation, and the latter was more significant. Moreover, the numbers of outermost and innermost parenchyma cells and the cell length of the uppermost internode reduced with the increasing temperatures.展开更多
The present study is about in vitro culture of cork oak, through callogenesis from nodes and internodes, withdrawn from seedlings of three months. These latter were obtained after acorns germination on peat. Nodes sho...The present study is about in vitro culture of cork oak, through callogenesis from nodes and internodes, withdrawn from seedlings of three months. These latter were obtained after acorns germination on peat. Nodes showed a high capacity for callogenesis and the best rate was obtained on a medium containing Woody Plant Medium (WPM) macronutrients, Murashige and Skoog (MS) micronutrients and vitamins, 4.5 μM of 6-Benzylaminopurine (BAP), 7 μM of 2-naphthalineacetic acid (NAA) and 30 g/L of Sucrose. Calluses are transplanted onto the same mineral solution, with or without growth regulators, and in the 3rd transplanting;small white embryos appear on the surface of calluses.展开更多
Performing the genetic mechanism research of internode length in bitter gourd has important guiding significance for making breeding strategy. A cross was made between CN19-1 and Thai4-6, and an F2 segregation populat...Performing the genetic mechanism research of internode length in bitter gourd has important guiding significance for making breeding strategy. A cross was made between CN19-1 and Thai4-6, and an F2 segregation population was constructed. The genetic characteristic of the internode length was analyzed through employing the major gene plus polygene mixed genetic model. The results showed that the internode length was continuous distribution in the F2 population. The optimum model for internode length genetic analysis was B-1. The additive effect values of two pairs of major genes controlling the internode length were 3.206 3 and 2.638 3, respectively, which showed a positive effect. The dominant effect values were-3.434 6 and-1.459 6, respectively, which showed a negative effect. The dominant degree of major genes is-1.07 and-0.55, respectively, indicating that the first pair of major genes was over dominant and the second pair of major genes was incompletely dominant. The heritability of the major gene was 82.25%, indicating the genetic stability was high. This study could provide a theoretical reference for the breeding of bitter gourd.展开更多
Breeding semi-dwarf varieties to improve lodging resistance has been proven to be enormously successful in increasing grain yield since the advent of the ＂green revolution.＂ However, the breeding of the majority of ...Breeding semi-dwarf varieties to improve lodging resistance has been proven to be enormously successful in increasing grain yield since the advent of the ＂green revolution.＂ However, the breeding of the majority of semi-dwarf rice varieties in Asia has been dependent mainly on genetic introduction of the mutant alleles of SD1, which encodes a gibberellin （GA） 20-oxidase, OsGA20ox2, for catalyzing GA biosynthesis. Here, we report a new rice lodging-resistance gene, Shortened Basal lnternodes （SBI）, which encodes a gibberellin 2- oxidase and specifically controls the elongation of culm basal internodes through deactivating GA activity. SBI is predominantly expressed in culm basal internodes. Genetic analyses indicate that SBI is a semidominant gene affecting rice height and lodging resistance. SBI allelic variants display different activities and are associated with the height of rice varieties. Breeding with higher activity of the SBI allele generates new rice varieties with improved lodging resistance and increased yield. The discovery of the SB! provides a desirable gene resource for producing semi-dwarf rice phenotypes and offers an effective strategy for breeding rice varieties with enhanced lodging resistance and high yield.展开更多
Development of the graft union of explanted internode autografting of cucumber ( Cu-cumis sativus Linn.) cultured in vitro is regulated by plant hormones exogenously added to the media. The levels of auxin (indole-3-a...Development of the graft union of explanted internode autografting of cucumber ( Cu-cumis sativus Linn.) cultured in vitro is regulated by plant hormones exogenously added to the media. The levels of auxin (indole-3-acetic acid, IAA) and zeatin plus zeatin riboside (Z+ ZR) in graft unions and in 4 parts of the graft union have been analyzed by ELISA assay.展开更多
The dynamic changes of IAA in graft union of explanted internode autografting of Cucumber (Cucumis sativus Linn.) have been investigated using the immunohistochemical localization technique. It is shown that the effic...The dynamic changes of IAA in graft union of explanted internode autografting of Cucumber (Cucumis sativus Linn.) have been investigated using the immunohistochemical localization technique. It is shown that the efficiency of IAA fixation using lyophilization-gas fixation is higher than that using liquid chemical fixation. In contrast to few silver particles and no significant changes during the development of graft union cultured in hormone-free medium, more silver particles in graft union and significant changes of IAA related to graft union development have been found when graft union was cultured in medium supplemented with appropriate hormones. The fixation procedure of plant hormones and the roles of IAA in graft union are discussed.展开更多
Plant growth regulators(PGRs) are commonly used in cereal cropping systems to restrict plant height and control lodging. Ethephon has been reported to shorten internodes and increase grain yield of maize. To analyze t...Plant growth regulators(PGRs) are commonly used in cereal cropping systems to restrict plant height and control lodging. Ethephon has been reported to shorten internodes and increase grain yield of maize. To analyze the transcriptomic profiles of maize internode elongation following ethephon treatment, differentially expressed genes were compared between the treatment and contro samples of inbred line Zong 31 using the Affymetrix Maize Genome Array. According to the microarray data 326 probe sets showed significant change in expression Further research revealed that the most remarkable effects of ethephon on maize internodes elongation occurred during a 48 h period, when 89 differentially expressed genes were detected. There were dramatic change in transcript levels at 24 h and six Auxin transport genes and four gibberellin biosynthesis pathway genes were differentially expressed in Zong 31 in response to ethephon treatment. In summary, we showed that gaseous ethylene release is involved in internode meristem cell elongation through the regulation of plant hormone signaling in maize. This work provides a platform for studies in which candidate genes will be functionally tested for involvement in internode elongation.展开更多
This paper derives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and find a relation between ...This paper derives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and find a relation between conduction velocity and the impulse profile. Computer simulations are used to bolster the analysis.展开更多
[Objective] Changxuan 3S was thermo-sensitive genicmale sterile（TGMS）rice selected from irradiated seeds of Peiai 64S by 350 Gy^（60）Coγ-ray.The aim of the study was to confirm GA3 spraying dosage of Changxuan 3S ...[Objective] Changxuan 3S was thermo-sensitive genicmale sterile（TGMS）rice selected from irradiated seeds of Peiai 64S by 350 Gy^（60）Coγ-ray.The aim of the study was to confirm GA3 spraying dosage of Changxuan 3S with eui gene in its hybrid seed production.[Method] Changxuan 3S possessing eui gene and its parent Peiai 64S were chosen as materials.Comparison studies on sensitivity to GA3 in their hybrid seed production were carried out.[Result] The suitable stage for spraying GA3 in the hybrid seed production of Changxuan 3S was at 10% of panicles headed;The optimal dosage was 90 g/hm2 with 2 split sprayings,the first spraying of 45 g/hm2 at heading of 10% panicles and the second one of 45 g/hm2 on the following day.Under the condition of spraying GA3 at the rate of 90 g/hm2,the panicle neck exsertions of Changxuan 3S was ＋1.78 cm,and exserted stigma rate and seed setting rate of Changxuan 3S were 96.87% and 36.44%,being 21.46% and 16.33% more than those of Peiai 64S,respectively.The theoretical yield of ＂Changxuan 3S/9311＂ reached 2 931.90 kg/hm2,which was increased by 1 259.40 kg/hm2 comparing with ＂Peiai 64S/9311＂.[Conclusion] Compared with Peiai 64S,Changxuan 3S is more sensitive to GA3,which results in no or little using GA3 in seed production of Changxuan 3S.Moreover,Changxuan 3S showed higher yield potential than Peiai 64S.展开更多
In the monocot rice species Oryza sativa L., one of the most striking morphological processes during reproductive development is the concurrence of panicle development with the sequential elongation of upper internod...In the monocot rice species Oryza sativa L., one of the most striking morphological processes during reproductive development is the concurrence of panicle development with the sequential elongation of upper internodes （UPIs）. To elucidate the underlying molecular mechanisms, we cloned the rice gene NECK LEAF 1 （NL1）, which when mutated results in delays in flowering time, smaller panicles with overgrown bracts and abnormal UPI elongation patterns. The NL1 gene encodes a GATA-type transcription factor with a single zinc finger domain, and its transcripts are de- tected predominantly in the bract primordia, which normally degenerate in the wild-type plants. Overexpression of NL1 in transgenic plants often gives rise to severe growth retardation, less vegetative phytomers and smaller leaves, suggesting that NL1 plays an important role in organ differentiation. A novel mutant allele of PLASTOCHRON1 （PLAD, a gene known to play a key role in regulating leaf initiation, was identified in this study. Genetic analysis demonstrated an interaction between nil and plal, with NL1 acting upstream of PLA1. The expression level and spatial pattern of PLA1 were found to be altered in the nil mutant. Furthermore, the expression of two regulators of flowering, Hd3a and OsMADS1, was also affected in the nil mutant. On the basis of these findings, we propose that NL1 is an intrinsic factor that modulates and coordinates organogenesis through regulating the expression of PLA1 and other regulatory genes during reproductive development in rice.展开更多
The morphogenetic responses to salt stress of TunisianPopu-lus alba clones were studied in order to promote their plantation in dam-aged saline areas. One year-old plants of threeP. alba clones （MA-104, MA-195 and OG...The morphogenetic responses to salt stress of TunisianPopu-lus alba clones were studied in order to promote their plantation in dam-aged saline areas. One year-old plants of threeP. alba clones （MA-104, MA-195 and OG） were subjected to progressive salt stress by irrigation during two consecutive years. The plants were grown in a nursery, inside plastic receptacles containing sandy soil and were irrigated with tap water （control） or 3-6 g/l NaCl solution. During this study, leaf epinasty, elongation rate, vigor, internode length, plant architecture, and number of buds were evaluated. Test clone response was highly dependent on the applied treatment and degree of accommodation.The most pronounced alterations were induced under 6g/l of NaCl treatment including leaf epinasty, leaf elongation rate delay, vigor decrease, internode length shortening, and morphogenetic modifications. These responses were less noticeable in the MA-104 clone with respect to the two other clones. The salt effect induced a delay in the leaf elongation rate on the MA-195 and OG clones leading to an early leaf maturity. The vigour and internode length of the MA-104 clone was less affected than the other clones. The OG clone was the most salt-sensitive thus, it developed shorter branches and more buds number than MA-195 and MA-104. The effect of long-term salt stress was to induce early flowering of theP. alba clones which suggests that mechanism of salt accommodation could be developed.展开更多
文摘Internode number and length are the foundation to constitute plant height, ear height and the above-ground spatial structure of maize plant. In this study, segregating populations were constructed between EHel with extremely low ear height and B73. Through the SNP-based genotyping and phenotypic characterization, 13 QTL distributed on the chromosomes (Chrs) of Chr1, Chr2, Chr5-Chr8 were detected for four traits of internode no. above ear (INa), average internode length above ear (ILaa), internode no. below ear (INb), and average internode length below ear (ILab). Phenotypic variation explained (PVE) by a single QTL ranged from 6.82% (qILab2-2) to 12.99% (qILaa5). Zm00001d016823 within the physical region of qILaa5, the major QTL for ILaa with the largest PVE was determined as the candidate through the genomic annotation and sequence alignment between EHel and B73. Product of Zm00001d016823 was annotated as a WEB family protein homogenous to At1g75720. qRT-PCR assay showed that Zm00001d016823 highly expressed within the tissue of internode, exhibiting statistically higher expression levels among internodes of IN4 to IN7 in EHel than those in B73 (P Zm00001d016823 might provide novel insight into molecular mechanism beyond phytohormones controlling internode development in maize.
基金This work was supported by the earmarked fund for China Agriculture Research System(CARS-02-16).
文摘The occurrence of high temperature(HT)in crop production is becoming more frequent and unpredictable with global warming,severely threatening food security.The state of an organ’s growth and development is largely determined by the temperature conditions it is exposed to over time.Maize is the main cereal crop,and its stem growth and plant architecture are closely related to lodging resistance,and especially sensitive to temperature.However,systematic research on the timing effect of HT on the sequentially developing internode and stem is currently lacking.To identify the timing effect of HT on the morphology and plasticity of the stem in maize,two hybrids(Zhengdan 958(ZD958),Xianyu 335(XY335))characterized by distinct morphological traits in the stem were exposed to a 7-day HT treatment from the V6 to V17 stages(Vn presents the vegetative stage with n leaves fully expanded)in 2019-2020.The results demonstrated that exposure to HT during V6-V12 accelerated the rapid elongation of stems.For instance,HT occurring at V7 and V12 specifically promoted the lengths and weights of the 3rd-5th and 9th-11th internodes,respectively.Meanwhile,HT slowed the growth of internodes adjacent to the promoted internodes.Interestingly,compared with control,the plant height was significantly increased soon after HT treatment,but the promotion effect became narrower at the subsequent flowering stage,demonstrating a self-adjusting mechanism in the maize plant in response to HT.Importantly,HT altered the plant architectures,including a rising of the ear position and increase in the ear position coefficient.XY335 exhibited greater sensitivity in stem development than ZD958 under HT treatment.These findings improve our systematic understanding of the plasticity of internode and plant architecture in response to the timing of HT exposure.
基金Supported by National High Technology Research and Development Program of China(863Program,2010AA101301)Chinese Super Rice Breeding and Experiment Demonstration Program,Ministry of Agriculture+1 种基金the 0406 Program of zhejiang ProvinceScientific Research Fund of China National Rice Research Institute(2009RG001-5)~~
文摘[Objective] This study aimed to investigate the genetic effects and heterosis of plant height and internode traits of japonica-indica hybrid rice. [Methed] Incomplete diallel crosses were made between six japonica CMS lines and nine indica widecompatibility restorer lines; the genetic effects of plant height and internode traits of japonica-indica hybrid rice were analyzed using the additive-dominance genetic model. [Result] The ple, nt height, panicle length and the length of internode 1 of japonica-in- dica hybrid rice were mainly controlled by the additive effects; but the length of in- ternode 3, internode 4 and internode 5 were mainly controlled by dominance effects. Both the narrow sense heritability and broad sense heritability of plant height, panicle length, number of elongated internodes and length of most internodes reached signifi- cance level. The positive phenotypic correlation, genetic correlation, additive correla- tion and dominance correlation between plant height and panicle length, number of e- longated internodes and internode length were significant; and most of the other paired traits were significantly positively correlated. Heterosis analysis showed that the positive heterosis value over mid-parent and positive heterosis value over better- parent of the length of internode 3, internode 4, internode 5 and internode 6 reached significant level, and the heterosis value over mid-parent of plant height reached extreme significance level. [Conclusion] This study will provide reliable theoretical basis for the genetic improvement and heterosis utilization of plant height and internode traits in japonica-indica hybrid rice.
基金supported in part by the fiscal 2010 special grant from the president of the Prefectural University of Kumamoto
文摘We analyzed the relationship between internode number and intemode length for one of the largest bamboo, Phyllostachys pubescens Mazel ex Houz. For 50 sample culms with various sizes felled in a pure stand of P. pubescens, the intemode number was assigned from base to tip and the length for each internode was directly measured. The result indicated that the intemode length should be cumulated from base to tip, and then the cumulated internode length should be relativized by the total culm length. It was inappropriate to relativize the internode length by the maximum intenode length. In addition, the relationship between the relative internode number （the intemode number relativized by the total number of intemodes） and the relative cumulated internode length should be described not by a power function but by a sigmoid function such as the third-order function. The determined function enabled us to estimate the actual internode length, with the root mean squared error being 4 cm. In conclusion, the mathematical expression presented here, i.e., the relativization of the cumulated internode length by the total culm length and the application of the sigmoid function, will be useful in describing the relationship between internode number and internode length for P. pubescens.
基金supported by the China Agriculture Research System (CARS11-HNCX)the Major Science and Technology Plan of Hainan Province (ZDKJ2021012)+3 种基金the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences (1630052022008)the National Key Research and Development Program of China (2018YFD1000501)the National Natural Science Foundation of China (31501378)the Hainan Yazhou Bay Seed Lab (B21HJ0303)。
文摘Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.
基金supported by the Natural Science Foundation of Guangdong Province,China(S2012020011043)the National High Technology Research and Development Program of China(2014AA10A605)+2 种基金the Special Fund for Agro-scientific Research in the Public Interest(201503106)Modern Agriculture Industry Technology System for Rice in Guangdong Province(2016LM1066,2017LM1066,2018LM1066)the Swiss Agency for Development and Cooperation through its funding of “Closing Rice Yield Gaps in Asia” Project(CORIGAP)
文摘Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.
基金supported by USDA grant 2008-35100-19244 to the University of Floridathe University of Florida Agricultural Experiment Stationby the Center for Medical, Agricultural, and Veterinary Entomology, U.S. Department of AgricultureAgricultural Research Service, Gainesville, FL, USA
文摘A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville,FL, USA to investigate how a soybean(Glycine max L. Merr.) cultivar, Maverick(maturity group III, indeterminate), responded to three elevated temperatures, ELT,(day/night of 34/26 °C, 38/30 °C, and 42/34 °C) in comparison to a control growth temperature(30/22 °C).Carbon dioxide(CO_2) concentration was maintained at 700 μmol mol^(-1) in each compartment by a processor controlled air-sampling and CO_2-injection system. Three sequential experiments were conducted at different times of year(summer, autumn, and early spring)to investigate the effect of intensity, timing, and duration of ELT on soybean node number,internode elongation, mainstem length, and number of pods set per plant. At the control temperature, the soybean plants grown in the polycarbonate greenhouse were taller than field-grown plants. When plants were grown under continuous ELT applied soon after sowing or at initial flowering, the number of nodes increased with increasing ELT intensity,whereas the length of individual internodes decreased. When ELT treatment was applied during the beginning of flowering stage(R1–R2) or earlier, more nodes were produced and the length of affected internodes was decreased. When the ELT was imposed later at reproductive stage R5+ just before the beginning of seed filling, effects on node numbers and internode lengths were negligible. Short-term(10-day) duration of ELT applied at four stages from V3 to R5+ did not significantly affect final mean numbers of nodes or mean mainstem lengths. Possible mechanisms of elevated temperature effects on soybean internode elongation and node number(internode number) are discussed. Total pod numbers per plant increased linearly with mainstem node numbers and mainstem length.Furthermore, total pod numbers per plant were greatest at 34/26 °C rather than at the control temperature of 30/22 °C(and remained high at 38/30 °C). Mild increases in temperature might not threaten, but actually increase, yields of soybean in northerly zones where this crop is currently grown at slightly suboptimal temperatures. However, a sustained increase in ambient temperature would likely threaten soybean yields.
文摘The characteristics of vascular bundle in the first internode from top and grain-filling of heavy panicle type hybrid rice(HPTHR) were studied. The results were as follows: The HPTHR had more vascular bundles and a much bigger area of single vascular bundle, all vascular bundle, all phloem and all xylem in the first inter-node than Shanyou63. The vascular bundles had the similar load of spikelet number and sink capacity between the HPTHR and Shanyou63. The HPTHR had not only a larger sink but also normal grain-filling and sink-filling, high seed-setting rate and heavier panicle. Those characteristics of vascular bundle were the biological bases for the larger and heavier panicle of HPTHR. The results also indicated that the breeding model of HPTHR was an effective measure for the super high-yielding rice breeding.
文摘Changxuan 3S, a thermo-sensitive genic male sterile （TGMS） rice line with eui gene, is derived from the TGMS rice line Pei＇ai 64S by irradiation with 350 Gy of ^60Co γ-ray. To elucidate the uppermost internode elongation of the TGMS line with eui gene, Changxuan 3S and its parent Pei＇ai 64S were used to study the effects of temperature on panicle exsertion. At 24℃, the uppermost internode of Changxuan 3S elongated the fastest from the 4^th day before flowering to 0 day （flowering）, being 2.1-fold as that of Pei＇ai 64S, whereas it elongated slowly during the 12^th day to the 4^th day before flowering and the 1^st to the 3^rd day after flowering. The uppermost internode of Changxuan 3S exserted from the flag leaf sheath at 22℃, 24℃ and 26℃, and the length of elongated uppermost internode increased with the decreasing temperatures. At 28℃, though the panicles of Changxuan 3S were still enclosed in the leaf sheath, the degree of panicle enclosure was significantly lower compared with Pei＇ai 64S. Cytological studies on Changxuan 3S showed that the uppermost internode elongation was attributed to the increase of cell number and cell elongation, and the latter was more significant. Moreover, the numbers of outermost and innermost parenchyma cells and the cell length of the uppermost internode reduced with the increasing temperatures.
文摘The present study is about in vitro culture of cork oak, through callogenesis from nodes and internodes, withdrawn from seedlings of three months. These latter were obtained after acorns germination on peat. Nodes showed a high capacity for callogenesis and the best rate was obtained on a medium containing Woody Plant Medium (WPM) macronutrients, Murashige and Skoog (MS) micronutrients and vitamins, 4.5 μM of 6-Benzylaminopurine (BAP), 7 μM of 2-naphthalineacetic acid (NAA) and 30 g/L of Sucrose. Calluses are transplanted onto the same mineral solution, with or without growth regulators, and in the 3rd transplanting;small white embryos appear on the surface of calluses.
基金Supported by National Natural Science Foundation of China(31601758)
文摘Performing the genetic mechanism research of internode length in bitter gourd has important guiding significance for making breeding strategy. A cross was made between CN19-1 and Thai4-6, and an F2 segregation population was constructed. The genetic characteristic of the internode length was analyzed through employing the major gene plus polygene mixed genetic model. The results showed that the internode length was continuous distribution in the F2 population. The optimum model for internode length genetic analysis was B-1. The additive effect values of two pairs of major genes controlling the internode length were 3.206 3 and 2.638 3, respectively, which showed a positive effect. The dominant effect values were-3.434 6 and-1.459 6, respectively, which showed a negative effect. The dominant degree of major genes is-1.07 and-0.55, respectively, indicating that the first pair of major genes was over dominant and the second pair of major genes was incompletely dominant. The heritability of the major gene was 82.25%, indicating the genetic stability was high. This study could provide a theoretical reference for the breeding of bitter gourd.
基金This work was supported by the Chinese Academy of Sciences （CEMPS2016009 XDA08020203）, the Ministry of Science and Technology of China （2013CB127002 2016YFD0102102）, and the National Natural Science Foundation of China （31571635）.
文摘Breeding semi-dwarf varieties to improve lodging resistance has been proven to be enormously successful in increasing grain yield since the advent of the ＂green revolution.＂ However, the breeding of the majority of semi-dwarf rice varieties in Asia has been dependent mainly on genetic introduction of the mutant alleles of SD1, which encodes a gibberellin （GA） 20-oxidase, OsGA20ox2, for catalyzing GA biosynthesis. Here, we report a new rice lodging-resistance gene, Shortened Basal lnternodes （SBI）, which encodes a gibberellin 2- oxidase and specifically controls the elongation of culm basal internodes through deactivating GA activity. SBI is predominantly expressed in culm basal internodes. Genetic analyses indicate that SBI is a semidominant gene affecting rice height and lodging resistance. SBI allelic variants display different activities and are associated with the height of rice varieties. Breeding with higher activity of the SBI allele generates new rice varieties with improved lodging resistance and increased yield. The discovery of the SB! provides a desirable gene resource for producing semi-dwarf rice phenotypes and offers an effective strategy for breeding rice varieties with enhanced lodging resistance and high yield.
文摘Development of the graft union of explanted internode autografting of cucumber ( Cu-cumis sativus Linn.) cultured in vitro is regulated by plant hormones exogenously added to the media. The levels of auxin (indole-3-acetic acid, IAA) and zeatin plus zeatin riboside (Z+ ZR) in graft unions and in 4 parts of the graft union have been analyzed by ELISA assay.
文摘The dynamic changes of IAA in graft union of explanted internode autografting of Cucumber (Cucumis sativus Linn.) have been investigated using the immunohistochemical localization technique. It is shown that the efficiency of IAA fixation using lyophilization-gas fixation is higher than that using liquid chemical fixation. In contrast to few silver particles and no significant changes during the development of graft union cultured in hormone-free medium, more silver particles in graft union and significant changes of IAA related to graft union development have been found when graft union was cultured in medium supplemented with appropriate hormones. The fixation procedure of plant hormones and the roles of IAA in graft union are discussed.
基金supported by the National High Technology Research and Development Program of China (2011AA10 A206)
文摘Plant growth regulators(PGRs) are commonly used in cereal cropping systems to restrict plant height and control lodging. Ethephon has been reported to shorten internodes and increase grain yield of maize. To analyze the transcriptomic profiles of maize internode elongation following ethephon treatment, differentially expressed genes were compared between the treatment and contro samples of inbred line Zong 31 using the Affymetrix Maize Genome Array. According to the microarray data 326 probe sets showed significant change in expression Further research revealed that the most remarkable effects of ethephon on maize internodes elongation occurred during a 48 h period, when 89 differentially expressed genes were detected. There were dramatic change in transcript levels at 24 h and six Auxin transport genes and four gibberellin biosynthesis pathway genes were differentially expressed in Zong 31 in response to ethephon treatment. In summary, we showed that gaseous ethylene release is involved in internode meristem cell elongation through the regulation of plant hormone signaling in maize. This work provides a platform for studies in which candidate genes will be functionally tested for involvement in internode elongation.
文摘This paper derives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and find a relation between conduction velocity and the impulse profile. Computer simulations are used to bolster the analysis.
基金Supported by Technology Research and Development Program of Hunan Provincial Science&Technology Department(2008FJ3066)Study on Hormones Regulation of Uppermost Internode Elongation of Eui Tgms Rice Changxuan 3S and GA3 Spraying Dosoge in ItsHybrid Seed Production,Key Program of Hunan Provincial Department of Education(09A066)+1 种基金Natural Science Foundation of Hunan Province(07JJ6032)Study on Expansion Inuppermost Internode of Rice Male Sterile Line with Eui Geng~~
文摘[Objective] Changxuan 3S was thermo-sensitive genicmale sterile（TGMS）rice selected from irradiated seeds of Peiai 64S by 350 Gy^（60）Coγ-ray.The aim of the study was to confirm GA3 spraying dosage of Changxuan 3S with eui gene in its hybrid seed production.[Method] Changxuan 3S possessing eui gene and its parent Peiai 64S were chosen as materials.Comparison studies on sensitivity to GA3 in their hybrid seed production were carried out.[Result] The suitable stage for spraying GA3 in the hybrid seed production of Changxuan 3S was at 10% of panicles headed;The optimal dosage was 90 g/hm2 with 2 split sprayings,the first spraying of 45 g/hm2 at heading of 10% panicles and the second one of 45 g/hm2 on the following day.Under the condition of spraying GA3 at the rate of 90 g/hm2,the panicle neck exsertions of Changxuan 3S was ＋1.78 cm,and exserted stigma rate and seed setting rate of Changxuan 3S were 96.87% and 36.44%,being 21.46% and 16.33% more than those of Peiai 64S,respectively.The theoretical yield of ＂Changxuan 3S/9311＂ reached 2 931.90 kg/hm2,which was increased by 1 259.40 kg/hm2 comparing with ＂Peiai 64S/9311＂.[Conclusion] Compared with Peiai 64S,Changxuan 3S is more sensitive to GA3,which results in no or little using GA3 in seed production of Changxuan 3S.Moreover,Changxuan 3S showed higher yield potential than Peiai 64S.
文摘In the monocot rice species Oryza sativa L., one of the most striking morphological processes during reproductive development is the concurrence of panicle development with the sequential elongation of upper internodes （UPIs）. To elucidate the underlying molecular mechanisms, we cloned the rice gene NECK LEAF 1 （NL1）, which when mutated results in delays in flowering time, smaller panicles with overgrown bracts and abnormal UPI elongation patterns. The NL1 gene encodes a GATA-type transcription factor with a single zinc finger domain, and its transcripts are de- tected predominantly in the bract primordia, which normally degenerate in the wild-type plants. Overexpression of NL1 in transgenic plants often gives rise to severe growth retardation, less vegetative phytomers and smaller leaves, suggesting that NL1 plays an important role in organ differentiation. A novel mutant allele of PLASTOCHRON1 （PLAD, a gene known to play a key role in regulating leaf initiation, was identified in this study. Genetic analysis demonstrated an interaction between nil and plal, with NL1 acting upstream of PLA1. The expression level and spatial pattern of PLA1 were found to be altered in the nil mutant. Furthermore, the expression of two regulators of flowering, Hd3a and OsMADS1, was also affected in the nil mutant. On the basis of these findings, we propose that NL1 is an intrinsic factor that modulates and coordinates organogenesis through regulating the expression of PLA1 and other regulatory genes during reproductive development in rice.
文摘The morphogenetic responses to salt stress of TunisianPopu-lus alba clones were studied in order to promote their plantation in dam-aged saline areas. One year-old plants of threeP. alba clones （MA-104, MA-195 and OG） were subjected to progressive salt stress by irrigation during two consecutive years. The plants were grown in a nursery, inside plastic receptacles containing sandy soil and were irrigated with tap water （control） or 3-6 g/l NaCl solution. During this study, leaf epinasty, elongation rate, vigor, internode length, plant architecture, and number of buds were evaluated. Test clone response was highly dependent on the applied treatment and degree of accommodation.The most pronounced alterations were induced under 6g/l of NaCl treatment including leaf epinasty, leaf elongation rate delay, vigor decrease, internode length shortening, and morphogenetic modifications. These responses were less noticeable in the MA-104 clone with respect to the two other clones. The salt effect induced a delay in the leaf elongation rate on the MA-195 and OG clones leading to an early leaf maturity. The vigour and internode length of the MA-104 clone was less affected than the other clones. The OG clone was the most salt-sensitive thus, it developed shorter branches and more buds number than MA-195 and MA-104. The effect of long-term salt stress was to induce early flowering of theP. alba clones which suggests that mechanism of salt accommodation could be developed.
