[Objectives]To screen effective agents for the management of root rot in tobacco floating seedlings.[Methods]A total of eight treatments were implemented in a large-scale field trial,which included three replications....[Objectives]To screen effective agents for the management of root rot in tobacco floating seedlings.[Methods]A total of eight treatments were implemented in a large-scale field trial,which included three replications.Each treatment was administered at the recommended dosages.[Results]The application of Metalaxyl-M·Fludioxonil+amino acids demonstrated a control efficacy of 93.65%against root rot in tobacco floating seedlings.In comparison,the application of Metalaxyl-M·Fludioxonil alone exhibited a control efficacy of 88.42%.The most effective treatment for promoting root growth in tobacco seedlings was Metalaxyl-M·Fludioxonil+amino acids,which resulted in a 54.65%increase in root growth compared to the blank control.This was followed by the application of Metalaxyl-M·Fludioxonil alone,which yielded a 39.53%increase in root growth relative to the blank control.[Conclusions]The application of Metalaxyl-M·Fludioxonil+amino acids is recommended for use in the seedling pools of tobacco seedling cultivation.Specifically,it is advised to incorporate 1 mL of Metalaxyl-M·Fludioxonil and 2 mL of amino acids into each seedling tray prior to their introduction into the seedling pool.This treatment has demonstrated significant efficacy in preventing and controlling root rot in tobacco floating seedlings,while also promoting the health of the root system and ensuring the quality of transplanted tobacco seedlings.展开更多
The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,w...The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,we developed a novel hybrid seed production scheme using herbicide-resistance alleles(OsALS and CYP81A6).P/TGMS lines were bred for imazamox sensitivity and bentazon resistance,while male parents were engineered for the opposite traits.This system enables mechanical harvesting and ensures hybrid purity by eliminating self-pollinated contaminants through herbicide application.We identified suitable sterile lines and developed complementary male parents via breeding and CRISPR/Cas9 editing,validated through herbicide assays.This strategy enhances hybrid seed purity and mechanization efficiency in two-line hybrid rice production.展开更多
C-14-glutamate and C-14-arginine were spreaded on leaves of six-day old barley (Hordeum vulgare L.) seedlings that were treated with NaCl 200 mmol/L. The result showed that the pathway of arginine-->ornithine-->...C-14-glutamate and C-14-arginine were spreaded on leaves of six-day old barley (Hordeum vulgare L.) seedlings that were treated with NaCl 200 mmol/L. The result showed that the pathway of arginine-->ornithine-->proline existed in the six-day old barley seedlings and was provoked remarkably by NaCl treatment. After seven days, proline accumulation contributed via the arginine-->ornithine-->proline pathway was 1.0 - 1.5 folds of that via the glutamate-->proline pathway. The activation of arginine-->ornithine-->proline pathway by salt stress in the salt-tolerant cultivar 'Jian 4' was 1.7 - 2.0 folds of that in the salt-sensitive cultivar 'KP 7', which suggested that the activation of arginine-->ornithine-->proline pathway in barley seedlings played an important role in improving salt tolerance of plants.展开更多
[ Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [ Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to U...[ Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [ Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth were studied through hydroponics in laboratory. [ Result] The results showed that under irradiation of UV-B（ T1-0.15 W/m^2 and T2-0.45 W/m^2）, chlorophyll and indole-3-acetic acid（IAA） contents firstly decreased during the stress phase （1 -5 d） and then increased during the restoration phase （6 -9 d） while contents of malonadialdehyde（MDA） and abscisic acid（ABA） gradually increased during the imposition of UV-B radiation （1 -5 d） and subsequently decreased during recovery from UV-B stress （6 -9 d） . With adding of La （III） with the concentration of 20 mg · L^-1 , the decline/dse trend of chlorophyll, IAA, MDA and ABA contents was slowed down during the stress period while the rise/decline speed was accelerated during the recovery period. [ Conclusion] It suggests that the regulation of La （ III ） on membrane lipid peroxidation and endogenous hormones could increase chlorophyll and IAA contents, improve the metabolism of reactive oxygen species （ ROS）, inhibit membrane lipid peroxidation, decrease the accumulation amount of ABA and alleviate injury of UV-B radiation to soybean seedlings. Further, the protective potential of La （ III ） was better under low UV-B radiation than under high one.展开更多
The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the...The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 靘olm-2s-1 photosynthetic photon flux density (PPFD) and 500 靘olm-2s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 靘olm-2s-1 PPFD were slower than those at 200 靘olm-2s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.展开更多
Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora m...Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.展开更多
The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke抏rqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the ...The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke抏rqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the aeolian sandy soil in different ratios. Two-year-old Pinus sylvestris var. mongolica seedlings and plastic pots were used in the experiment. The experimental results indicated that: 1) the peat and weathered coal could significantly improve the physical and chemical prop-erties of aeolian sandy soil, and thus promoted the growth of seedlings; 2) the effect of peat on seedling growth, including height, base diameter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2% >10%>0 for root length, and 5%>2%>8% >10%>0 for biomass; 3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth of P. sylvestris var. mongolica seedlings.展开更多
[Objective] The purpose was to discuss the effects of different NaCl concentrations on fresh weight and dry weight,ion absorption and distribution in oil sunflower seedlings. [Method] Under the simulated salt environm...[Objective] The purpose was to discuss the effects of different NaCl concentrations on fresh weight and dry weight,ion absorption and distribution in oil sunflower seedlings. [Method] Under the simulated salt environment by using NaCl solutions at different concentrations,the dry weight,fresh weight and ion content of oil sunflower seedlings were determined. [Result] With the increase of NaCl concentration,the growth rate of oil sunflower seedling was inhibited. In addition,its fresh weight and dry weight also decreased; the fresh weight of leaf decreased most significantly by 60%,and that of cotyledon decreased most slightly by 13% at 200 mmol/L NaCl concentration. The dry weight of root,stem,leaf and cotyledon decreased by 35%,39%,55% and 8% respectively,showing a similar decreasing trend with fresh weight. Under NaCl stress,Na＋ content in root and stem of oil sunflower seedling increased while K＋ decreased. Na＋ content was mainly concentrated in roots and stems much more than in leaves; K＋ content in roots decreased most significantly by 21% compared with control,and it was relatively high in leaf. Ca2＋ and Mg2＋ content was decreased slightly in roots and stems; Ca2＋ content in leaves and cotyledons was stable; Mg2＋ content was slightly increased. [Conclusion] Oil sunflower maintained high mineral ion absorptionunder salt stress,that maybe the part reason for high salt tolerance of oil sunflower seedlings.展开更多
Two heat-tolerant rice varieties, N5 and TQ, were chosen as test materi- als. Specifically, rice seedlings （leaf age at 2.1）, cultivated in room, were treated at 40 ℃ for 7 d and some indices were measured, includi...Two heat-tolerant rice varieties, N5 and TQ, were chosen as test materi- als. Specifically, rice seedlings （leaf age at 2.1）, cultivated in room, were treated at 40 ℃ for 7 d and some indices were measured, including plant height, dry weight, leaf color, proline, malondialdehyde and conductivity. The results showed that high temperature advanced the growth of N5 seedlings, for example, plant height, root length and dry weight of ground parts all increased. However, high temperature prevented TQ seedlings growth, plant height in particular. Furthermore, high temper- ature treatment increased the content of chlorophyll of N5 and had none effects on PSII of N5, with little damages on membrane system. On the other hand, high temperature actually reduced PSII activity of TQ, and seriously damaged TQ mem- brane system. It is speculated that the differences of the two varieties lie on pro- duction or removing capacity of reactive oxide species.展开更多
[Objective] The research aimed to discuss the relationship between Glycine betaine and the salt-tolerance mechanism of different pumpkins and confirm the mechanism of betaine in salt-tolerance physiology.[Method] Taki...[Objective] The research aimed to discuss the relationship between Glycine betaine and the salt-tolerance mechanism of different pumpkins and confirm the mechanism of betaine in salt-tolerance physiology.[Method] Taking the seedlings of C.ficifolia and Qingli pumpkin as test materials,the effects of glycine betaine on the cell membrane permeability,MDA and root activity of two varieties of pumpkin seedlings under 300 mmol/L NaCl stress were studied.[Result] At suitable concentrations,glycine betaine could d...展开更多
Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedl...Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedlings of Guisangyou 12 were used as the materials and the comparative experiment on subculture multi-plication and root induction used different kinds,concentrations and combinations of exogenous hormones. [Result] The hormone combination of 0.1 mg/L IBA＋1.5 mg/L 6-BA＋0.03 mg/L TDZ showed the best effects to bud multiplication, and the multiple of bud multiplication was 5.28. The effects of NAA was better than IBA and IAA on root induction. The hormone combination of 2.0 mg/L NAA＋1.0 mg/L PP333 was most suitable to the root induction, in which the rooting rate arrived to 100%, the root number was 7.01 and the root length was 1.38 cm on average. [Conclusion] The results wil provide some technical reference for large-scale propagation of mul-berry seedlings in vitro.展开更多
With annual Bischofia javanica seedlings as experimental material, the plasticity and comprehensive evaluation methods were employed to investigate the effects of different shading degrees （100% NS （natural sunshine...With annual Bischofia javanica seedlings as experimental material, the plasticity and comprehensive evaluation methods were employed to investigate the effects of different shading degrees （100% NS （natural sunshine）, 41.3% NS, 14.6% NS and 3.6% NS） on B. javanica seedlings growth, so as to obtain the shade toler- ance in B. javanica. The results showed that with the shading degree increasing, the seedling height increment, diameter increment, leaf area, fresh weights （above- ground part, underground part and whole plant） and dry weights （aboveground part, underground part and whole plant） of B. javanica seedlings all increased first and then decreased, and reached peak values under 41.3% NS, while the total root length, average root diameter, total surface area, total root volume and total root number all presented a decreasing trend. Also the comprehensive evaluation by subordinate function value method and plasticity analysis were carried out on these growth indexes. It was concluded that B. javanica seedlings have medium shade tol- erance from the comDrehensive analysis of growth indexes.展开更多
Water transport at the root/soil interface of 1 year old Pinus sylvestris Linn. var. sylvestriformis (Takenouchi) Cheng et C. D. Chu seedlings under CO 2 doubling was studied by measuring soil electric conductanc...Water transport at the root/soil interface of 1 year old Pinus sylvestris Linn. var. sylvestriformis (Takenouchi) Cheng et C. D. Chu seedlings under CO 2 doubling was studied by measuring soil electric conductance to survey soil water profiles and comparing it with root distribution surveyed by soil coring and root harvesting in Changbai Mountain in 1999. The results were: (1) The profiles of soil water content were adjusted by root activity. The water content of the soil layer with abundant roots was higher. (2) When CO 2 concentration was doubled, water transport was more active at the root/soil interface and the roots were distributed into deeper layer. It was shown in this work that the method of measuring electric conductance is an inexpensive, non_destructive and relatively sensitive way for underground water transport process.展开更多
The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on aut...The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.展开更多
[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana （Musa AAA Cavendish subgroup cv.Brazil） was taken as test material...[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana （Musa AAA Cavendish subgroup cv.Brazil） was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels （5％,10％ and 15％） and time periods （24,48 and 72 h）.[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline （Pro） in seedling leaves from high to low was PEG15％,PEG10％ and PEG5％; the content of treatment of 5％ stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows：PEG15％＞PEG10％＞PEG5％,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5％ of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows：PEG10％＞PEG15％＞PEG5％ and the activity increased remarkably in the group with PEG at 5％ within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.展开更多
This study presents a drone-based aerial imaging method for automated rice seedling detection and counting in paddy fields.Utilizing a drone equipped with a high-resolution camera,images are captured 14 days postsowin...This study presents a drone-based aerial imaging method for automated rice seedling detection and counting in paddy fields.Utilizing a drone equipped with a high-resolution camera,images are captured 14 days postsowing at a consistent altitude of six meters,employing autonomous flight for uniform data acquisition.The approach effectively addresses the distinct growth patterns of both single and clustered rice seedlings at this early stage.The methodology follows a two-step process:first,the GoogleNet deep learning network identifies the location and center points of rice plants.Then,the U-Net deep learning network performs classification and counting of individual plants and clusters.This combination of deep learning models achieved a 90%accuracy rate in classifying and counting both single and clustered seedlings.To validate the method’s effectiveness,results were compared against traditional manual counting conducted by agricultural experts.The comparison revealed minimal discrepancies,with a variance of only 2–4 clumps per square meter,confirming the reliability of the proposed method.This automated approach offers significant benefits by providing an efficient,accurate,and scalable solution for monitoring seedling growth.It enables farmers to optimize fertilizer and pesticide application,improve resource allocation,and enhance overall crop management,ultimately contributing to increased agricultural productivity.展开更多
Using seed sowing cultivation method, the four-season soilless cultivation of the sprouting seedlings of Toona sinensis was carried out with different germination accelerating treatments, cultivation substrates, culti...Using seed sowing cultivation method, the four-season soilless cultivation of the sprouting seedlings of Toona sinensis was carried out with different germination accelerating treatments, cultivation substrates, cultivation environment and management technologies by using the corresponding treatment methods in different seasons, so as to produce the sprouting vegetable products of T. sinensis which was not restricted by seasons. The test results showed that using the mixed substrate of pedite and vermiculite in winter and spring can keep moisture but not too high, and the produced sprout vegetable had good quality and high yield.展开更多
The effects of apple dwarf stocks P22 and SH3 on the juvenile phase of Fuji seedlings were studied. The results showed that the juvenile phase could be shortened by more than two years when 2-year seedlings were graft...The effects of apple dwarf stocks P22 and SH3 on the juvenile phase of Fuji seedlings were studied. The results showed that the juvenile phase could be shortened by more than two years when 2-year seedlings were grafted on the dwarf stocks. The effects of P22 and SH3 were significantly different. Grafted on P22, the flowering node was less, the first flowing site was lower, and the juvenile phase was shorter than SH3. With the two stocks, the average first flowering site was more than 200 cm, the average flowering node was more than 100, and the lateral branch top bud was more than 50% in all first flowing seedlings.展开更多
[Objective] The study was to investigate the relationship between taurine and physiological activities of Lyium bararum seedlings. [Method] Through applying different concentrations of taurine(0, 10, 100, 500, 1 000, ...[Objective] The study was to investigate the relationship between taurine and physiological activities of Lyium bararum seedlings. [Method] Through applying different concentrations of taurine(0, 10, 100, 500, 1 000, 5 000 mg/L), the photosynthetic rate(Pn), stomatal conductance(Gs), and the activities of membrane protective enzymes superoxide dismutase(SOD) and peroxidase (POD) in the treated L. bararum seedlings were measured. [Result] Treatment of proper taurine concentration could to some extent enhance Pn and increase the POD and SOD activities, and meanwhile decreased the Gs and MDA content. And the optimum application amount of taurine was determined to be 500 mg/L. [Conclusion] Proper concentration of taurine has protective effects on the cell membrane of L. bararum seedlings.展开更多
[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine...[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks（the treament HC） is the optimal substratum in this study.展开更多
文摘[Objectives]To screen effective agents for the management of root rot in tobacco floating seedlings.[Methods]A total of eight treatments were implemented in a large-scale field trial,which included three replications.Each treatment was administered at the recommended dosages.[Results]The application of Metalaxyl-M·Fludioxonil+amino acids demonstrated a control efficacy of 93.65%against root rot in tobacco floating seedlings.In comparison,the application of Metalaxyl-M·Fludioxonil alone exhibited a control efficacy of 88.42%.The most effective treatment for promoting root growth in tobacco seedlings was Metalaxyl-M·Fludioxonil+amino acids,which resulted in a 54.65%increase in root growth compared to the blank control.This was followed by the application of Metalaxyl-M·Fludioxonil alone,which yielded a 39.53%increase in root growth relative to the blank control.[Conclusions]The application of Metalaxyl-M·Fludioxonil+amino acids is recommended for use in the seedling pools of tobacco seedling cultivation.Specifically,it is advised to incorporate 1 mL of Metalaxyl-M·Fludioxonil and 2 mL of amino acids into each seedling tray prior to their introduction into the seedling pool.This treatment has demonstrated significant efficacy in preventing and controlling root rot in tobacco floating seedlings,while also promoting the health of the root system and ensuring the quality of transplanted tobacco seedlings.
基金supported by the Zhongshan Biological Breeding Laboratory,China(Grant No.ZSBBL-KY2023-07)the Jiangsu Agricultural Science and Technology Innovation Fund,China(Grant No.CX(22)3138)+1 种基金the National Natural Science Foundation of China(Grant Nos.32101736,32002124)the Jiangsu Provincial Key Research and Development Program,China(Grant No.BE2021360-2).
文摘The photoperiod/thermo-sensitive genic male sterility(P/TGMS)system is crucial for hybrid rice production,but challenges persist in seed purity(due to fertility conversion and mixed male seeds)and mechanization.Here,we developed a novel hybrid seed production scheme using herbicide-resistance alleles(OsALS and CYP81A6).P/TGMS lines were bred for imazamox sensitivity and bentazon resistance,while male parents were engineered for the opposite traits.This system enables mechanical harvesting and ensures hybrid purity by eliminating self-pollinated contaminants through herbicide application.We identified suitable sterile lines and developed complementary male parents via breeding and CRISPR/Cas9 editing,validated through herbicide assays.This strategy enhances hybrid seed purity and mechanization efficiency in two-line hybrid rice production.
文摘C-14-glutamate and C-14-arginine were spreaded on leaves of six-day old barley (Hordeum vulgare L.) seedlings that were treated with NaCl 200 mmol/L. The result showed that the pathway of arginine-->ornithine-->proline existed in the six-day old barley seedlings and was provoked remarkably by NaCl treatment. After seven days, proline accumulation contributed via the arginine-->ornithine-->proline pathway was 1.0 - 1.5 folds of that via the glutamate-->proline pathway. The activation of arginine-->ornithine-->proline pathway by salt stress in the salt-tolerant cultivar 'Jian 4' was 1.7 - 2.0 folds of that in the salt-sensitive cultivar 'KP 7', which suggested that the activation of arginine-->ornithine-->proline pathway in barley seedlings played an important role in improving salt tolerance of plants.
基金Supported by the Foundation of State Developing and ReformingCommittee(No.IFZ20051210)the National Natural Science Foundationof China(No.30570323,No.20471030)the Programsin Science and Technology of Nantong(No.DE2009006,No.S2009019)~~
文摘[ Objective] The aim was to provide strategies for development of rare earth and control of environmental pollution. [ Method] Responses of membrane lipid peroxidation and endogenous hormones of soybean seedlings to UV-B radiation and rare earth were studied through hydroponics in laboratory. [ Result] The results showed that under irradiation of UV-B（ T1-0.15 W/m^2 and T2-0.45 W/m^2）, chlorophyll and indole-3-acetic acid（IAA） contents firstly decreased during the stress phase （1 -5 d） and then increased during the restoration phase （6 -9 d） while contents of malonadialdehyde（MDA） and abscisic acid（ABA） gradually increased during the imposition of UV-B radiation （1 -5 d） and subsequently decreased during recovery from UV-B stress （6 -9 d） . With adding of La （III） with the concentration of 20 mg · L^-1 , the decline/dse trend of chlorophyll, IAA, MDA and ABA contents was slowed down during the stress period while the rise/decline speed was accelerated during the recovery period. [ Conclusion] It suggests that the regulation of La （ III ） on membrane lipid peroxidation and endogenous hormones could increase chlorophyll and IAA contents, improve the metabolism of reactive oxygen species （ ROS）, inhibit membrane lipid peroxidation, decrease the accumulation amount of ABA and alleviate injury of UV-B radiation to soybean seedlings. Further, the protective potential of La （ III ） was better under low UV-B radiation than under high one.
文摘The time processes of photosynthetic induction responses to various irradiances in Korean pine (Pinus koraiensis) seedlings grown in open-light environments and in understory of forest were studied in an area near the Research Station of Changbai Mountain Forest Ecosystems, Jilin Province, China from July 15 to August 5, 1997. The results showed that at 200 靘olm-2s-1 photosynthetic photon flux density (PPFD) and 500 靘olm-2s-1 PPFD, the induction time for the photosynthetic rates of understory-grown seedlings to reach 50% and 90% steady-state net photosynthetic rates was longer than that of the open-grown seedlings. The induction responses of open-growth seedlings at 500 靘olm-2s-1 PPFD were slower than those at 200 靘olm-2s-1 PPFD, but it was the very reverse for understory-growth seedlings, which indicates that the photosynthetic induction times of Korean pine seedlings grown in the understory depended on the sunfleck intensity.
基金This paper was supported by the Heilongjiang Province Foundation for Distinguished Youth Scholars (JC-02-11)
文摘Camptotheca acuminata seeds were sown in sterilized sands in the greenhouse in February of 2005. After 90-day growth, seedlings were inoculated with three species of arbuscular mycorrhizal fungi （AMF）, Acaulospora mellea, Glomus diaphanum and Sclerocystis sinuosa.. The height, biomass, and absorptions of nitrogen and phosphorus of C. acuminata seedlings inoculated with AMF were investigated. The results showed that the formation of AM promoted the height growth and biomass accumulation of seedlings significantly and improved the absorption of phosphorus in seedlings. The height and biomass of mycorrhizal seedlings were 1.2 and 1.6 times higher than those of the non-mycorrhizal seedlings. The absorption of nitrogen was less influenced by the formation of AM. The nitrogen content in mycorrhizal seedling was equal to that of non-mycorrhizal seedlings. Compared with non-mycorrhizal seedlings, the nitrogen content of mycorrhizal seedlings inoculated with A. mellea changed considerably in the root, stem and leaves. The difference in nitrogen content was not significant between mycorrhizal seedlings inoculated with G. diaphanum and S. sinuosa. The AM formation stimulated the absorption of phosphorus, especially in roots, and also changed the allocation of nitrogen and phosphorus in different organs of seedlings. Compared with non-mycorrhizal seedlings, the ratio of nitrogen and phosphorus in mycorrhizal roots increased, but reduced in stem and leaves.
基金This research was supported by Key Knowledge Innova-tion Project (SCXZD0102) of Institute of Applied Ecology Chinese Academy of Sciences and sponsored by the Science and Technology Department of Inner Mongolia Autonomic Region,P. R. China (2001010)
文摘The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke抏rqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the aeolian sandy soil in different ratios. Two-year-old Pinus sylvestris var. mongolica seedlings and plastic pots were used in the experiment. The experimental results indicated that: 1) the peat and weathered coal could significantly improve the physical and chemical prop-erties of aeolian sandy soil, and thus promoted the growth of seedlings; 2) the effect of peat on seedling growth, including height, base diameter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2% >10%>0 for root length, and 5%>2%>8% >10%>0 for biomass; 3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth of P. sylvestris var. mongolica seedlings.
基金Supported by CAS Western Light, " Dr. West funded " Project(0806270XBB)~~
文摘[Objective] The purpose was to discuss the effects of different NaCl concentrations on fresh weight and dry weight,ion absorption and distribution in oil sunflower seedlings. [Method] Under the simulated salt environment by using NaCl solutions at different concentrations,the dry weight,fresh weight and ion content of oil sunflower seedlings were determined. [Result] With the increase of NaCl concentration,the growth rate of oil sunflower seedling was inhibited. In addition,its fresh weight and dry weight also decreased; the fresh weight of leaf decreased most significantly by 60%,and that of cotyledon decreased most slightly by 13% at 200 mmol/L NaCl concentration. The dry weight of root,stem,leaf and cotyledon decreased by 35%,39%,55% and 8% respectively,showing a similar decreasing trend with fresh weight. Under NaCl stress,Na＋ content in root and stem of oil sunflower seedling increased while K＋ decreased. Na＋ content was mainly concentrated in roots and stems much more than in leaves; K＋ content in roots decreased most significantly by 21% compared with control,and it was relatively high in leaf. Ca2＋ and Mg2＋ content was decreased slightly in roots and stems; Ca2＋ content in leaves and cotyledons was stable; Mg2＋ content was slightly increased. [Conclusion] Oil sunflower maintained high mineral ion absorptionunder salt stress,that maybe the part reason for high salt tolerance of oil sunflower seedlings.
基金Supported by National Natural Science Foundation of China(30771156,31200387)~~
文摘Two heat-tolerant rice varieties, N5 and TQ, were chosen as test materi- als. Specifically, rice seedlings （leaf age at 2.1）, cultivated in room, were treated at 40 ℃ for 7 d and some indices were measured, including plant height, dry weight, leaf color, proline, malondialdehyde and conductivity. The results showed that high temperature advanced the growth of N5 seedlings, for example, plant height, root length and dry weight of ground parts all increased. However, high temperature prevented TQ seedlings growth, plant height in particular. Furthermore, high temper- ature treatment increased the content of chlorophyll of N5 and had none effects on PSII of N5, with little damages on membrane system. On the other hand, high temperature actually reduced PSII activity of TQ, and seriously damaged TQ mem- brane system. It is speculated that the differences of the two varieties lie on pro- duction or removing capacity of reactive oxide species.
基金Supported by the National Natural Science Foundation of China(30660015)Key Laboratory of Vegetable Genetics and Physiology of Ministry of Agriculture of the People s Republic of China(2003-2005)~~
文摘[Objective] The research aimed to discuss the relationship between Glycine betaine and the salt-tolerance mechanism of different pumpkins and confirm the mechanism of betaine in salt-tolerance physiology.[Method] Taking the seedlings of C.ficifolia and Qingli pumpkin as test materials,the effects of glycine betaine on the cell membrane permeability,MDA and root activity of two varieties of pumpkin seedlings under 300 mmol/L NaCl stress were studied.[Result] At suitable concentrations,glycine betaine could d...
基金Supported by Post-graduate Innovation Program of Guangxi(YCSZ2013007)~~
文摘Objective The purpose of this experiment was to investigate the effects of exogenous hormone factors on subculture multiplication and root induction of tis-suecultured seedlings in mulberry. [Method] The aseptic seedlings of Guisangyou 12 were used as the materials and the comparative experiment on subculture multi-plication and root induction used different kinds,concentrations and combinations of exogenous hormones. [Result] The hormone combination of 0.1 mg/L IBA＋1.5 mg/L 6-BA＋0.03 mg/L TDZ showed the best effects to bud multiplication, and the multiple of bud multiplication was 5.28. The effects of NAA was better than IBA and IAA on root induction. The hormone combination of 2.0 mg/L NAA＋1.0 mg/L PP333 was most suitable to the root induction, in which the rooting rate arrived to 100%, the root number was 7.01 and the root length was 1.38 cm on average. [Conclusion] The results wil provide some technical reference for large-scale propagation of mul-berry seedlings in vitro.
文摘With annual Bischofia javanica seedlings as experimental material, the plasticity and comprehensive evaluation methods were employed to investigate the effects of different shading degrees （100% NS （natural sunshine）, 41.3% NS, 14.6% NS and 3.6% NS） on B. javanica seedlings growth, so as to obtain the shade toler- ance in B. javanica. The results showed that with the shading degree increasing, the seedling height increment, diameter increment, leaf area, fresh weights （above- ground part, underground part and whole plant） and dry weights （aboveground part, underground part and whole plant） of B. javanica seedlings all increased first and then decreased, and reached peak values under 41.3% NS, while the total root length, average root diameter, total surface area, total root volume and total root number all presented a decreasing trend. Also the comprehensive evaluation by subordinate function value method and plasticity analysis were carried out on these growth indexes. It was concluded that B. javanica seedlings have medium shade tol- erance from the comDrehensive analysis of growth indexes.
文摘Water transport at the root/soil interface of 1 year old Pinus sylvestris Linn. var. sylvestriformis (Takenouchi) Cheng et C. D. Chu seedlings under CO 2 doubling was studied by measuring soil electric conductance to survey soil water profiles and comparing it with root distribution surveyed by soil coring and root harvesting in Changbai Mountain in 1999. The results were: (1) The profiles of soil water content were adjusted by root activity. The water content of the soil layer with abundant roots was higher. (2) When CO 2 concentration was doubled, water transport was more active at the root/soil interface and the roots were distributed into deeper layer. It was shown in this work that the method of measuring electric conductance is an inexpensive, non_destructive and relatively sensitive way for underground water transport process.
基金This paper was supported by National Natural Science Foundation of China (Grant No. 39670607).
文摘The classification of seedlings is important to ensure the viability of seedlings after transplantation and is acknowledged as a key factor in forestation and environmental improvement. Based on numerous papers on automatic seedling classification (ASC), the seedling grading theory, traditional grading methods, the background and the proceeding of ASC techniques are described. The automation of the measurement of seedling morphological characteristics by photoelectric meters and computer vision is studied, and the automatic methods of the current grading systems are described respectively. And the further researches on ASC by computer vision are proposed.
文摘[Objective] The aim was to explore physiological responses of Brazil banana seedlings to drought stress simulated by PEG-6000.[Method] Brazil banana （Musa AAA Cavendish subgroup cv.Brazil） was taken as test materials to explore changes of physiological indices of banana seedlings under drought stresses simulated by PEG-6000,including three stress levels （5％,10％ and 15％） and time periods （24,48 and 72 h）.[Result] Relative water content and chlorophyll content both declined under different stress levels and in different times.The content of proline （Pro） in seedling leaves from high to low was PEG15％,PEG10％ and PEG5％; the content of treatment of 5％ stress in 24 h was of insignificant differences with that of the control and the contents in rest treatments were all remarkably higher compared with the control.POD activities of seedling leaves from high to low were as follows：PEG15％＞PEG10％＞PEG5％,and POD activity was of significant differences among treatments; POD activity achieved the peak in treatment group with 5％ of stress,and POD activities of different groups were all higher compared with the control.The activity of root system in treatment groups with PEG at different concentrations was as follows：PEG10％＞PEG15％＞PEG5％ and the activity increased remarkably in the group with PEG at 5％ within 24,48 and 72 h,though the activity dropped significantly within 72 h and slowly in 24 and 48 h.[Conclusion] It can be concluded that relative water content,chlorophyll content,Pro content and activity and root activity can be references of banana resistance to drought.
基金funded by the Ministry of Education and Training Project(code number:B2023-TCT-08).
文摘This study presents a drone-based aerial imaging method for automated rice seedling detection and counting in paddy fields.Utilizing a drone equipped with a high-resolution camera,images are captured 14 days postsowing at a consistent altitude of six meters,employing autonomous flight for uniform data acquisition.The approach effectively addresses the distinct growth patterns of both single and clustered rice seedlings at this early stage.The methodology follows a two-step process:first,the GoogleNet deep learning network identifies the location and center points of rice plants.Then,the U-Net deep learning network performs classification and counting of individual plants and clusters.This combination of deep learning models achieved a 90%accuracy rate in classifying and counting both single and clustered seedlings.To validate the method’s effectiveness,results were compared against traditional manual counting conducted by agricultural experts.The comparison revealed minimal discrepancies,with a variance of only 2–4 clumps per square meter,confirming the reliability of the proposed method.This automated approach offers significant benefits by providing an efficient,accurate,and scalable solution for monitoring seedling growth.It enables farmers to optimize fertilizer and pesticide application,improve resource allocation,and enhance overall crop management,ultimately contributing to increased agricultural productivity.
文摘Using seed sowing cultivation method, the four-season soilless cultivation of the sprouting seedlings of Toona sinensis was carried out with different germination accelerating treatments, cultivation substrates, cultivation environment and management technologies by using the corresponding treatment methods in different seasons, so as to produce the sprouting vegetable products of T. sinensis which was not restricted by seasons. The test results showed that using the mixed substrate of pedite and vermiculite in winter and spring can keep moisture but not too high, and the produced sprout vegetable had good quality and high yield.
文摘The effects of apple dwarf stocks P22 and SH3 on the juvenile phase of Fuji seedlings were studied. The results showed that the juvenile phase could be shortened by more than two years when 2-year seedlings were grafted on the dwarf stocks. The effects of P22 and SH3 were significantly different. Grafted on P22, the flowering node was less, the first flowing site was lower, and the juvenile phase was shorter than SH3. With the two stocks, the average first flowering site was more than 200 cm, the average flowering node was more than 100, and the lateral branch top bud was more than 50% in all first flowing seedlings.
基金Supported by the Natural Science Foundation of Ningxia University(NS0506)the Natural Science Foundation of Ningxia Autonomous Re-gion(NZ0603)~~
文摘[Objective] The study was to investigate the relationship between taurine and physiological activities of Lyium bararum seedlings. [Method] Through applying different concentrations of taurine(0, 10, 100, 500, 1 000, 5 000 mg/L), the photosynthetic rate(Pn), stomatal conductance(Gs), and the activities of membrane protective enzymes superoxide dismutase(SOD) and peroxidase (POD) in the treated L. bararum seedlings were measured. [Result] Treatment of proper taurine concentration could to some extent enhance Pn and increase the POD and SOD activities, and meanwhile decreased the Gs and MDA content. And the optimum application amount of taurine was determined to be 500 mg/L. [Conclusion] Proper concentration of taurine has protective effects on the cell membrane of L. bararum seedlings.
文摘[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks（the treament HC） is the optimal substratum in this study.
