Seaweed extract contains plant growth regulators and bio-stimulants that enhance plant growth and development.In Bangladesh,winter rice(Boro rice)in the nursery bed often shows poor seed emergence and weak seedling gr...Seaweed extract contains plant growth regulators and bio-stimulants that enhance plant growth and development.In Bangladesh,winter rice(Boro rice)in the nursery bed often shows poor seed emergence and weak seedling growth due to low temperature.This problem can be addressed by using seaweed extract as a seed priming agent and bio-stimulant.The objective of this study was to evaluate the effectiveness of seaweed extract(Crop Plus)on seed emergence,seedling growth,and vigor of winter rice in the nursery.Two experiments were conducted at Bangladesh Agricultural University using BRRI dhan89.The laboratory experiment consisted of 17 treatments combining three concentrations of Crop Plus(5000,10,000 and 15,000 ppm)and four priming durations(6,12,18,and 24 h),along with hydro-priming and a no priming as control.Seed priming with 15,000 ppm for 24 h produced the highest germination percentage and superior seedling growth traits.The nursery bed experiment comprised 11 treatments combining two doses(1 mL m^(−2)and 2 mL m^(−2))of Crop Plus and five different foliar application schedules,along with a control.All treatments outperformed the control,with the best results from Crop Plus@2 mL m^(−2)applied at 20 and 30 days after sowing(DAS).Overall,the treatment involving seed priming with 15,000 ppm seaweed extract for 24 h,followed by nursery application at 2 mL m^(−2)at 20 and 30 DAS,resulted in higher germination and improved early growth of winter rice.However,further validation across multiple locations,seasons,and rice cultivars is recommended.展开更多
Elevated CO_(2)(eCO_(2))may mitigate stress-induced damage to cotton(Gossypium spp.)growth and development.However,understanding the early-stage responses of cotton to multiple abiotic stressors at eCO_(2)levels has b...Elevated CO_(2)(eCO_(2))may mitigate stress-induced damage to cotton(Gossypium spp.)growth and development.However,understanding the early-stage responses of cotton to multiple abiotic stressors at eCO_(2)levels has been limited.This study quantified the impacts of chilling(CS,22/14℃,day/night temperature),heat(HS,38/30℃),drought(DS,50%irrigation of the control),and salt(SS,8 d S m-1)stresses on pigments,physiology,growth,and development of 14 upland cotton cultivars under ambient CO_(2)(aCO_(2),420 ppm;current)and eCO_(2)(700 ppm;future)levels during the vegetative stage.The eCO_(2)partially negated the effects of all stresses by improving one or more of the pigments,physiological,growth,and development traits,except CS.For instance,HS at aCO_(2)significantly increased stomatal conductance by 36%compared with non-stressed plants at aCO_(2).However,HS at eCO_(2)significantly decreased stomatal conductance by 18%compared with HS at aCO_(2).The first squaring was delayed by one day under SS at aCO_(2)but two days earlier under SS at eCO_(2)than non-stressed plants at aCO_(2).Root and shoot dry mass and the total leaf area were significantly higher under all stresses,except for CS,at the eCO_(2)compared with similar stresses at the aCO_(2).Most growth and development traits,including plant height,leaf area,and shoot dry mass,displayed a mirroring response pattern between aCO_(2)and eCO_(2)under all environments except CS.Cultivars exhibited significant interaction with stressed environments.Further,results revealed differential sensitivity and adaptation potential of cultivars to stress environments at varying CO_(2)levels.This study highlights the need to consider eCO_(2)in designing breeding programs to develop stress-tolerant varieties for future cotton-growing environments.展开更多
Concerned that fewer than 20%of adolescents meet the World Health Organization(WHO)’s physical activity(PA)guidelines of engaging in≥60 min each day of the week of moderate-to-vigorous PA(MVPA),classifying them as i...Concerned that fewer than 20%of adolescents meet the World Health Organization(WHO)’s physical activity(PA)guidelines of engaging in≥60 min each day of the week of moderate-to-vigorous PA(MVPA),classifying them as insufficiently active,1 Araujo et al.2 sought to identify the global prevalence of adolescents reporting less frequent MVPA(≥60 min per day of MVPA≥1 days per week)and identify differences in this prevalence by age,gender.展开更多
[Objective] The aim was to research the effect of concentration of NO-3-N on root vigor and rhizosphere pH of winter wheat seedlings under water culture.[Method]By selecting Hoagland's nutritional solution as cult...[Objective] The aim was to research the effect of concentration of NO-3-N on root vigor and rhizosphere pH of winter wheat seedlings under water culture.[Method]By selecting Hoagland's nutritional solution as cultural medium and winter wheat as material of experiment,on the basis,testing root vigor,nutrient solution NO-3 and change of pH values under the different level of disposal,such as high(containing NO-3-N 15 mmol/L),medium(containing NO-3-N 7.5 mmol/L)and lower(containing NO-3-N 2.5 mmol/L).[Result]The results of this research showed that the effect of different nitrogen level on the wastage of nutrient solution NO-3,the changes of pH values and root vigor is obvious under the hydroponics condition.[Conclusion]Though NO-3 is a safe nitrogen sources when it was supplied to plants too more,it would restrain assimilation on nitrate nitrogen farther,but when it was supplied to plants too little,it would lead to deficiency of NO-3 that plants uptake and decrease of root activity,so it isn't useful to wheat young seedling to absorb nitrogen nutrition.展开更多
[Objective]The aim was to study the effects of sunflower artificial aging on seed vigor and physiological characteristics.[Method] The varieties of seed germination capacity,vigor of germination,germination index,vigo...[Objective]The aim was to study the effects of sunflower artificial aging on seed vigor and physiological characteristics.[Method] The varieties of seed germination capacity,vigor of germination,germination index,vigor index,peroxidase（POD） activity,superoxide dismutase（SOD） activity and malondialdehyde（MDA） content for four sunflower germplasms such as＇SunM20＇,＇Deep Purple Minle＇,＇Da San Kui Hua 4＇and＇Ji Kui 24＇were studied under high temperature and high humidity conditions（100% RH,45 ℃） for different days（0 d,2 d,4 d,6 d,8 d,10 d）.[Result]The result showed that the germination capacity,vigor of germination,germination index,vigor index,POD activity,SOD activity declined gradually with the increase of seed aging days,whereas MDA content enhanced by degrees;The diggerences of resistance to artifical aging existed among the four accessions,＇SunM20＇was the most resistant one,and exhibited the strongest seed vigor,highest activities of two protective enzyme（POD,SOD） and lowest content of MDA at the uniform condition,moreover,the seed vigor and protective enzyme activities of＇SunM20＇changed slowest among the four materials during the aging process.[Conclusion]The distinct reduction of POD,SOD activities maybe the main reasons for the decrease of sunflower seed vigor at the artificial aging,and the gradual accumulation of a few MDA accelerated seeds aging.展开更多
The quantitative trait loci （QTLs） for the seedling vigor traits under 12℃ cold water irrigation, such as the seedling height, the seedling fresh weight, the seedling dry weight, and their cold response index, were...The quantitative trait loci （QTLs） for the seedling vigor traits under 12℃ cold water irrigation, such as the seedling height, the seedling fresh weight, the seedling dry weight, and their cold response index, were identified using an F2：3 population including 200 individuals and lines derived from a cross of indica and japonica ＂Milyang 23/Jileng 1＂ with microsatellite markers. All seedling vigor traits exhibited a continuous distribution near normal in F3 lines; these traits were quantitative traits controlled by multiple genes. Twelve QTLs conferring the seedling vigor traits under cold water irrigation were detected on chromosomes 1, 2, 7, 8, and 12, which explained the observed phenotypic variance from 5.2% to 17.9%. Among them, qCSH2 and qCSH12 were located in RM262-RM263 on chromosome 2 and RM270-RM17 on chromosome 12, respectively, which were associated with the seedling height, qSDW12 and qCSDW1 were located in RM19-RM270 on chromosome 12 and RM 129-RM9 on chromosome 1, respectively, which were correlated with the seedling dry weight and its cold response index, and the explained 16.6%, 17.9%, 15.9%, and 16.2% of the observed phenotypic variation, respectively. These QTLs alleles were derived from cold-tolerant parent Jileng 1; the gene actions of the two front genes showed their additive effect, and the two genes belind showed dominant and over dominant effects, respectively.展开更多
To explore the change rule of seed vigor and seed application technology of rice PTGMS lines with low temperature storage,Zhun S,Y58S,Feng S and Guangzhan 63-4S stored in the seed bank with the temperature of 8-10 ℃ ...To explore the change rule of seed vigor and seed application technology of rice PTGMS lines with low temperature storage,Zhun S,Y58S,Feng S and Guangzhan 63-4S stored in the seed bank with the temperature of 8-10 ℃ and with the relative humidity of 55% for different years were used as the materials to study the properties of seed vigor,growth and development in the field, etc. The re- sults showed that the germination potential, germination rate, germination index and vigor index of rice PTGMS lines seeds showed downward trends as the time of low temperature storage prolonged,and all of the germination rates of the seeds within five years were over 60%. The conductivity in the soaked solution of seeds was significantly increased with the prolonged low temperature storage time. Seedling rate,root length,white root number,base stem width and seedling dry weight of seeds showed downward trends as the time of low temperature storage prolonged. There was no significant difference between two integral seedling qualities of seeds within 4-6 years in low temperature storage. Compared with the germination rate of low temperature storage seeds soaking for 6,12 and 24 h,the appropriate soak time of long time low temperature storage or low vigor seeds was 12 h. A serious natural aging phenomenon occurred in low temperature storage seeds after out of the storage. The germination rate of seeds placed under natural condition for 50 d decreased obviously. The duration from seeding to heading of Zhun S,Y58S and Feng S shortened as the time of low temperature storage prolonged, while the vari- ation of panicle duration of all PTGMS lines was not obvious. In conclusion, rice PTGMS line seeds with low temperature storage in 5 years could still be used nor- mally. However.seeds after low temperature storage should be sowed as soon as possible, and the soaking time of low vigor seeds should be shortened,and the possibility that the decreased duration from seeding to heading should also be con- sidered.展开更多
[Objective] The experiment aimed to study the growth characteristics of hydroponic bowl lotus. [Method] The lotus variety Hongxia was chosen as the experimental material. Two treatments, hydroponics and soil culture w...[Objective] The experiment aimed to study the growth characteristics of hydroponic bowl lotus. [Method] The lotus variety Hongxia was chosen as the experimental material. Two treatments, hydroponics and soil culture were set to measure their photosynthetic indices, chlorophyll content and root vigor, and to observe their leaf tissue structure and stomatal characteristics. [Result] The findings indicated that there are no differences in the leaf physiological indices between bowl lotus under hydroponics and soil culture, while the leaf stomata of hydroponic bowl lotus is bigger and its amount is larger than that of soil-culture bowl lotus. At the same time, the ratio of the palisade tissue thickness to spongy tissue thickness is small,and its leaf tissue structure is loose. The root vigor of hydroponic bowl lotus reached its summit earlier, then began to drop. Whereas, the root activity of soil-culture lotus sustained increasing, with vigorous growth. [Conclusion] Therefore, it indicated that hydroponic bowl lotus can adapt to the aquatic-culture environment well and quickly, meanwhile, it also enters into its aging period quickly and its growth cycle gets shorter.展开更多
This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and compre...This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.展开更多
In Chinese culture,the horse is a symbol of vigor,strength,and resilience,heralding a future of steady progress and prosperous development,President Xi Jinping said when extending Spring Festival greetings at a recept...In Chinese culture,the horse is a symbol of vigor,strength,and resilience,heralding a future of steady progress and prosperous development,President Xi Jinping said when extending Spring Festival greetings at a reception on February 14 in Beijing to ring in the Chinese New Year-the Year of the Horse.This statement,resonating with the heart of the world’s most populous national celebration,offers a profound lens through which to understand not just a festival,but the pulsating energy of contemporary China.展开更多
Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influ...Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influenced by genetic background and environmental effects during seed development and storage conditions. The latest research on physiological mechanism in seed vigor showed that at the late stage of seed development, the development of seed vigor involves some stress-resistant substances including late embryogenesis abundant （LEA） protein, oligosaccharides and abscisic acid （ABA）. Whereas the loss of seed vigor, or seed aging and deterioration, could be attributed to lipid peroxidation, chromosome deformation and genes aberrance, and embryo protein degradation, etc. Seed vigor is a quantitative character controlled by multi-genes. Genetic and quantitative trait locus （QTL） analyses on seed-vigor trait in model plants, such as Arabidopsis and rice, are mostly concentrated on related morphology traits, whereas few physiological traits have been researched. It was concluded that, all of the QTL genetic characteristics of seed vigorincluding QTL quantities, its locus on chromosome, genetic effects, and interaction effects between genetic and environment, differed with plant species and used seed-vigor traits.展开更多
Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize see...Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% MC.The damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot length.The results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both cultivars.For obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,respectively.Furthermore,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both cultivars.When the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot length.Damage to the endosperm resulted in little effect on seedling performance.Flint maize DD2 was more tolerant to mechanical threshing than dent maize JK968.These results provided technical reference for the production and processing of high vigor maize seeds.展开更多
Seed vigor is an important characteristic of seed quality,and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment.In the present study,the quantitative ...Seed vigor is an important characteristic of seed quality,and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment.In the present study,the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage,including germination rate,final germination percentage,and germination index,were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Daguandao and indica IR28,and using the multiple interval mapping (MIM) approach.The results show that indica rice presented stronger seed vigor during the germination stage than japonica rice.A total of ten QTLs,and at least five novel alleles,were detected to control rice seed vigor,and the amount of variation (R2) explained by an individual QTL ranged from 7.5% to 68.5%,with three major QTLs with R2>20%.Most of the QTLs detected here are likely to coincide with QTLs for seed weight,seed size,or seed dormancy,suggesting that the rice seed vigor might be correlated with seed weight,seed size,and seed dormancy.At least five QTLs are novel alleles with no previous reports of seed vigor genes in rice,and those major or minor QTLs could be used to significantly improve the seed vigor by marker-assisted selection (MAS) in rice.展开更多
基金funded by Bangladesh Agricultural University Research System(BAURES)through the Project No.2024/48/BAU.
文摘Seaweed extract contains plant growth regulators and bio-stimulants that enhance plant growth and development.In Bangladesh,winter rice(Boro rice)in the nursery bed often shows poor seed emergence and weak seedling growth due to low temperature.This problem can be addressed by using seaweed extract as a seed priming agent and bio-stimulant.The objective of this study was to evaluate the effectiveness of seaweed extract(Crop Plus)on seed emergence,seedling growth,and vigor of winter rice in the nursery.Two experiments were conducted at Bangladesh Agricultural University using BRRI dhan89.The laboratory experiment consisted of 17 treatments combining three concentrations of Crop Plus(5000,10,000 and 15,000 ppm)and four priming durations(6,12,18,and 24 h),along with hydro-priming and a no priming as control.Seed priming with 15,000 ppm for 24 h produced the highest germination percentage and superior seedling growth traits.The nursery bed experiment comprised 11 treatments combining two doses(1 mL m^(−2)and 2 mL m^(−2))of Crop Plus and five different foliar application schedules,along with a control.All treatments outperformed the control,with the best results from Crop Plus@2 mL m^(−2)applied at 20 and 30 days after sowing(DAS).Overall,the treatment involving seed priming with 15,000 ppm seaweed extract for 24 h,followed by nursery application at 2 mL m^(−2)at 20 and 30 DAS,resulted in higher germination and improved early growth of winter rice.However,further validation across multiple locations,seasons,and rice cultivars is recommended.
基金supported by the Mississippi Agricultural and Forestry Experiment Station,Special Research Initiative(MAFES-SRI),USA,the USDA-Agricultural Research Service(USDA-ARS)(58-6064-3-007)the National Institute of Food and Agriculture,USA(MIS-430030)。
文摘Elevated CO_(2)(eCO_(2))may mitigate stress-induced damage to cotton(Gossypium spp.)growth and development.However,understanding the early-stage responses of cotton to multiple abiotic stressors at eCO_(2)levels has been limited.This study quantified the impacts of chilling(CS,22/14℃,day/night temperature),heat(HS,38/30℃),drought(DS,50%irrigation of the control),and salt(SS,8 d S m-1)stresses on pigments,physiology,growth,and development of 14 upland cotton cultivars under ambient CO_(2)(aCO_(2),420 ppm;current)and eCO_(2)(700 ppm;future)levels during the vegetative stage.The eCO_(2)partially negated the effects of all stresses by improving one or more of the pigments,physiological,growth,and development traits,except CS.For instance,HS at aCO_(2)significantly increased stomatal conductance by 36%compared with non-stressed plants at aCO_(2).However,HS at eCO_(2)significantly decreased stomatal conductance by 18%compared with HS at aCO_(2).The first squaring was delayed by one day under SS at aCO_(2)but two days earlier under SS at eCO_(2)than non-stressed plants at aCO_(2).Root and shoot dry mass and the total leaf area were significantly higher under all stresses,except for CS,at the eCO_(2)compared with similar stresses at the aCO_(2).Most growth and development traits,including plant height,leaf area,and shoot dry mass,displayed a mirroring response pattern between aCO_(2)and eCO_(2)under all environments except CS.Cultivars exhibited significant interaction with stressed environments.Further,results revealed differential sensitivity and adaptation potential of cultivars to stress environments at varying CO_(2)levels.This study highlights the need to consider eCO_(2)in designing breeding programs to develop stress-tolerant varieties for future cotton-growing environments.
文摘Concerned that fewer than 20%of adolescents meet the World Health Organization(WHO)’s physical activity(PA)guidelines of engaging in≥60 min each day of the week of moderate-to-vigorous PA(MVPA),classifying them as insufficiently active,1 Araujo et al.2 sought to identify the global prevalence of adolescents reporting less frequent MVPA(≥60 min per day of MVPA≥1 days per week)and identify differences in this prevalence by age,gender.
基金Supported by the Key Programfromthe National Natural Science Foundation of China(30230230)the National Natural Science Foundation Agricultural Program of China(30070429)Scientific Research Program for Universities in Inner Mongolia Autonomous Region(NJZY07120)~~
文摘[Objective] The aim was to research the effect of concentration of NO-3-N on root vigor and rhizosphere pH of winter wheat seedlings under water culture.[Method]By selecting Hoagland's nutritional solution as cultural medium and winter wheat as material of experiment,on the basis,testing root vigor,nutrient solution NO-3 and change of pH values under the different level of disposal,such as high(containing NO-3-N 15 mmol/L),medium(containing NO-3-N 7.5 mmol/L)and lower(containing NO-3-N 2.5 mmol/L).[Result]The results of this research showed that the effect of different nitrogen level on the wastage of nutrient solution NO-3,the changes of pH values and root vigor is obvious under the hydroponics condition.[Conclusion]Though NO-3 is a safe nitrogen sources when it was supplied to plants too more,it would restrain assimilation on nitrate nitrogen farther,but when it was supplied to plants too little,it would lead to deficiency of NO-3 that plants uptake and decrease of root activity,so it isn't useful to wheat young seedling to absorb nitrogen nutrition.
文摘[Objective]The aim was to study the effects of sunflower artificial aging on seed vigor and physiological characteristics.[Method] The varieties of seed germination capacity,vigor of germination,germination index,vigor index,peroxidase（POD） activity,superoxide dismutase（SOD） activity and malondialdehyde（MDA） content for four sunflower germplasms such as＇SunM20＇,＇Deep Purple Minle＇,＇Da San Kui Hua 4＇and＇Ji Kui 24＇were studied under high temperature and high humidity conditions（100% RH,45 ℃） for different days（0 d,2 d,4 d,6 d,8 d,10 d）.[Result]The result showed that the germination capacity,vigor of germination,germination index,vigor index,POD activity,SOD activity declined gradually with the increase of seed aging days,whereas MDA content enhanced by degrees;The diggerences of resistance to artifical aging existed among the four accessions,＇SunM20＇was the most resistant one,and exhibited the strongest seed vigor,highest activities of two protective enzyme（POD,SOD） and lowest content of MDA at the uniform condition,moreover,the seed vigor and protective enzyme activities of＇SunM20＇changed slowest among the four materials during the aging process.[Conclusion]The distinct reduction of POD,SOD activities maybe the main reasons for the decrease of sunflower seed vigor at the artificial aging,and the gradual accumulation of a few MDA accelerated seeds aging.
基金This work was supported by Key Technologies R & D Program (No. 2006BAD13B01) the National Natural Science Foundation of China (No.30070421)+1 种基金973 Foundation (No. 2004CB117201) Cooperative Research between China and Korea (2004-2007).
文摘The quantitative trait loci （QTLs） for the seedling vigor traits under 12℃ cold water irrigation, such as the seedling height, the seedling fresh weight, the seedling dry weight, and their cold response index, were identified using an F2：3 population including 200 individuals and lines derived from a cross of indica and japonica ＂Milyang 23/Jileng 1＂ with microsatellite markers. All seedling vigor traits exhibited a continuous distribution near normal in F3 lines; these traits were quantitative traits controlled by multiple genes. Twelve QTLs conferring the seedling vigor traits under cold water irrigation were detected on chromosomes 1, 2, 7, 8, and 12, which explained the observed phenotypic variance from 5.2% to 17.9%. Among them, qCSH2 and qCSH12 were located in RM262-RM263 on chromosome 2 and RM270-RM17 on chromosome 12, respectively, which were associated with the seedling height, qSDW12 and qCSDW1 were located in RM19-RM270 on chromosome 12 and RM 129-RM9 on chromosome 1, respectively, which were correlated with the seedling dry weight and its cold response index, and the explained 16.6%, 17.9%, 15.9%, and 16.2% of the observed phenotypic variation, respectively. These QTLs alleles were derived from cold-tolerant parent Jileng 1; the gene actions of the two front genes showed their additive effect, and the two genes belind showed dominant and over dominant effects, respectively.
文摘To explore the change rule of seed vigor and seed application technology of rice PTGMS lines with low temperature storage,Zhun S,Y58S,Feng S and Guangzhan 63-4S stored in the seed bank with the temperature of 8-10 ℃ and with the relative humidity of 55% for different years were used as the materials to study the properties of seed vigor,growth and development in the field, etc. The re- sults showed that the germination potential, germination rate, germination index and vigor index of rice PTGMS lines seeds showed downward trends as the time of low temperature storage prolonged,and all of the germination rates of the seeds within five years were over 60%. The conductivity in the soaked solution of seeds was significantly increased with the prolonged low temperature storage time. Seedling rate,root length,white root number,base stem width and seedling dry weight of seeds showed downward trends as the time of low temperature storage prolonged. There was no significant difference between two integral seedling qualities of seeds within 4-6 years in low temperature storage. Compared with the germination rate of low temperature storage seeds soaking for 6,12 and 24 h,the appropriate soak time of long time low temperature storage or low vigor seeds was 12 h. A serious natural aging phenomenon occurred in low temperature storage seeds after out of the storage. The germination rate of seeds placed under natural condition for 50 d decreased obviously. The duration from seeding to heading of Zhun S,Y58S and Feng S shortened as the time of low temperature storage prolonged, while the vari- ation of panicle duration of all PTGMS lines was not obvious. In conclusion, rice PTGMS line seeds with low temperature storage in 5 years could still be used nor- mally. However.seeds after low temperature storage should be sowed as soon as possible, and the soaking time of low vigor seeds should be shortened,and the possibility that the decreased duration from seeding to heading should also be con- sidered.
基金Supported by Key Scientific and Technological Project of Henan Province(072102150001)~~
文摘[Objective] The experiment aimed to study the growth characteristics of hydroponic bowl lotus. [Method] The lotus variety Hongxia was chosen as the experimental material. Two treatments, hydroponics and soil culture were set to measure their photosynthetic indices, chlorophyll content and root vigor, and to observe their leaf tissue structure and stomatal characteristics. [Result] The findings indicated that there are no differences in the leaf physiological indices between bowl lotus under hydroponics and soil culture, while the leaf stomata of hydroponic bowl lotus is bigger and its amount is larger than that of soil-culture bowl lotus. At the same time, the ratio of the palisade tissue thickness to spongy tissue thickness is small,and its leaf tissue structure is loose. The root vigor of hydroponic bowl lotus reached its summit earlier, then began to drop. Whereas, the root activity of soil-culture lotus sustained increasing, with vigorous growth. [Conclusion] Therefore, it indicated that hydroponic bowl lotus can adapt to the aquatic-culture environment well and quickly, meanwhile, it also enters into its aging period quickly and its growth cycle gets shorter.
文摘This study was conducted to investigate the effects of different packaging methods on seed germination and vigor under a long-term bank storage condition, selecting suitable packaging materials and methods, and comprehensively estimate changes in seed vigor of seeds stored with different packaging materials. Hibiscus cannabinus L. seeds were stored in aluminium box, seed box, glass bottle, POlyethylene film bag, sack and kraft paper bag as packaging materials in a, long-term bank and tested for their seeds germinability, electrical conductivity and field seedling rate after 31 years. The results showed that the kenaf seeds with an initial germination rate of 88% exhibited the germination rates over 79.7% after being stored in the 6 packaging materials for 31 years, the germination rates of seeds packaged with paper bag and sack and of those sealed in film bag and aluminium box showed significantly decreased germination rates, while the seeds sealed in seed boxes and glass bottles exhibited non-significant decreases in seed germination rate, and their germination rates were still above 85%. Seed box and glass bottle were the packaging materials most suitable for long-term safe storage of kenaf seeds with a safe storage period long than 31 years.
文摘In Chinese culture,the horse is a symbol of vigor,strength,and resilience,heralding a future of steady progress and prosperous development,President Xi Jinping said when extending Spring Festival greetings at a reception on February 14 in Beijing to ring in the Chinese New Year-the Year of the Horse.This statement,resonating with the heart of the world’s most populous national celebration,offers a profound lens through which to understand not just a festival,but the pulsating energy of contemporary China.
文摘Seed vigor is a more promising seed quality character reflecting potential seed germination, field emergence and seed storage ability under different conditions than standard germination. Standard germination is influenced by genetic background and environmental effects during seed development and storage conditions. The latest research on physiological mechanism in seed vigor showed that at the late stage of seed development, the development of seed vigor involves some stress-resistant substances including late embryogenesis abundant （LEA） protein, oligosaccharides and abscisic acid （ABA）. Whereas the loss of seed vigor, or seed aging and deterioration, could be attributed to lipid peroxidation, chromosome deformation and genes aberrance, and embryo protein degradation, etc. Seed vigor is a quantitative character controlled by multi-genes. Genetic and quantitative trait locus （QTL） analyses on seed-vigor trait in model plants, such as Arabidopsis and rice, are mostly concentrated on related morphology traits, whereas few physiological traits have been researched. It was concluded that, all of the QTL genetic characteristics of seed vigorincluding QTL quantities, its locus on chromosome, genetic effects, and interaction effects between genetic and environment, differed with plant species and used seed-vigor traits.
基金supported by the earmarked fund for China Agriculture Research System(CARS-02-10)the Special Fund for Agro-scientific Research in the Public Interest,China(201303002)the National Natural Science Foundation of China(31771891)
文摘Mechanical threshing used when preparing maize seeds for planting subjects seed to damage and reduces seed quality.The purpose of this study was to assess the effect of mechanical threshing on the quality of maize seed threshed at different moisture contents(MCs).Seeds of dent maize JK968 and flint maize DD2 were threshed at 12,15,18,21,and 24% MC.The damage degree was determined by iodine staining,and seed vigor was assessed by standard germination(SG),cold test germination(CTG),accelerated aging germination(AAG),seedling emergence rate,and seedling root and shoot length.The results showed that the damage percentage increased,and the seed vigor parameters decreased with increasing seed MC during threshing in both cultivars.For obtaining high seed quality,indicated by at least 90,85,and 80% of SG,AAG,and CTG,respectively,JK 968 and DD2 should be threshed at MC lower than 15 and 18%,respectively.Furthermore,the damage mainly occurred in the apical part of seeds,irrespective of the threshing MC in both cultivars.When the embryo was damaged,seedling emergence rates were significantly reduced with great influence on shoot length.Damage to the endosperm resulted in little effect on seedling performance.Flint maize DD2 was more tolerant to mechanical threshing than dent maize JK968.These results provided technical reference for the production and processing of high vigor maize seeds.
基金Project supported by the National Natural Science Foundation of China (No. 31000748)the Natural Science Foundation of Jiangsu Province (No. BK2010452)the Science and Technology Innovation Foun-dation of Nanjing Agricultural University (No. KJ09003), China
文摘Seed vigor is an important characteristic of seed quality,and rice cultivars with strong seed vigor are desirable in direct-sowing rice production for optimum stand establishment.In the present study,the quantitative trait loci (QTLs) of three traits for rice seed vigor during the germination stage,including germination rate,final germination percentage,and germination index,were investigated using one recombinant inbred line (RIL) population derived from a cross between japonica Daguandao and indica IR28,and using the multiple interval mapping (MIM) approach.The results show that indica rice presented stronger seed vigor during the germination stage than japonica rice.A total of ten QTLs,and at least five novel alleles,were detected to control rice seed vigor,and the amount of variation (R2) explained by an individual QTL ranged from 7.5% to 68.5%,with three major QTLs with R2>20%.Most of the QTLs detected here are likely to coincide with QTLs for seed weight,seed size,or seed dormancy,suggesting that the rice seed vigor might be correlated with seed weight,seed size,and seed dormancy.At least five QTLs are novel alleles with no previous reports of seed vigor genes in rice,and those major or minor QTLs could be used to significantly improve the seed vigor by marker-assisted selection (MAS) in rice.
