目前人们仍不清楚温度是如何影响发育中的大豆（Glycine max L．）种子蛋白质和脂肪积累过程以及基因型不同的大豆是否对温度具有相同的反应。研究拟通过对3个基因型大豆在不同温度处理下，种子发育过程中的蛋白质和脂肪的积累模式研究...目前人们仍不清楚温度是如何影响发育中的大豆（Glycine max L．）种子蛋白质和脂肪积累过程以及基因型不同的大豆是否对温度具有相同的反应。研究拟通过对3个基因型大豆在不同温度处理下，种子发育过程中的蛋白质和脂肪的积累模式研究，以了解温度对种子组分的调节机理。3个基因型大豆品种（Evans，PI132．217，和Proto）种子盆栽在温度为27／20％（中温）的生长箱中生长到开花。在开花后第10天，将其中的一个生长箱的温度调节到35／27℃（高温）；另一个调到20／12℃（低温）。生长在高温和中温条件下的大豆，在开花的第21天开始收集豆荚，每3d取1次样。生长在低温条件下的大豆，在开花的第25天开始收集豆荚，每5d取1次样。结果表明，3个基因型大豆种子均在高温下生长快，成熟早，在中温下生长速率最大，低温下生长速率低但种子生长期延长。当种子获得60％-70％总干重时种子脂肪含量达到最大（中温），高温使其提前出现，低温则被推后。在低温下，种子中蛋白质和脂肪两者积累模式相同，但蛋白质积累速率低。在高温和中温条件下，种子蛋白质和脂肪的积累模式不同。在种子获得60％～70％的总干重之前，蛋白质和脂肪积累模式相同，但在种子获得60％～70％的总干重之后，蛋白质积累呈上升趋势，而脂肪积累停止或下降。同时在种子发育的晚期伴随着蛋白质含量增加，淀粉和蔗糖含量快速下降。虽然3个基因型大豆种子的蛋白质和脂肪积累模式均明显受温度影响，但在不同温度条件下和不同生长阶段中高蛋白质品种Proto和PI132．217（蛋白质稳定型）蛋白质含量总是高于低蛋白质品种Evans，而且两者差异显著。这一研究表明温度不能改变品种在蛋白质和脂肪合成上的遗传特性。遗传育种在提高大豆种子蛋白质含量上仍起�展开更多
A glasshouse study compared the growth and phosphorus （P） efficiency of 96 genotypes of soybean [Glycine max （L.） Merrill] in a P-deficient soil. The soybean genotypes differed greatly in growth, nodulation and P ...A glasshouse study compared the growth and phosphorus （P） efficiency of 96 genotypes of soybean [Glycine max （L.） Merrill] in a P-deficient soil. The soybean genotypes differed greatly in growth, nodulation and P uptake after growing in the soil for 45 days, with shoot biomass ranging from 0.91 to 1.75 g per plant. The application of P improved biomass production, nodulation and P uptake and decreased root to shoot ratio, root length and surface area and P utilization efficiency. The 96 soybean genotypes were divided into 3 categories in P efficiency using the principal component analysis and cluster analysis, and 4 categories according to F values in combination with growth potentials. The Pefficient genotypes were associated with high biomass production, root to shoot ratio, root length and surface area and P uptake but low shoot to root P concentration ratio under P deficiency. The results indicate that there is a substantial genotypic variation in P efficiency in existing germplasm, and that P efficiency was correlated positively with dry weights of shoots and roots, ratio of root to shoot dry weight, root length and surface area, root P content and total P uptake. The shoot dry weight under P deficiency and relative shoot dry weight （deficient P/adequate P supply） are effective and simple indicators for screening P-efficient genotypes at the seedling stage.展开更多
A two-year study was carried out in Giza Agricultural Experiments and Research Station, Agricultural Research Center (ARC), Giza, Egypt in the 2020 and 2021 summer seasons to evaluate the relative tolerance of ten soy...A two-year study was carried out in Giza Agricultural Experiments and Research Station, Agricultural Research Center (ARC), Giza, Egypt in the 2020 and 2021 summer seasons to evaluate the relative tolerance of ten soybean genotypes for cotton leafworm infestation under field conditions. Soybean genotypes H<sub>11</sub>L<sub>145</sub>, H<sub>155</sub>, H<sub>113</sub>, H<sub>4</sub>L<sub>4</sub>, H<sub>15</sub>L<sub>17</sub>, H<sub>129</sub>, H<sub>30</sub>, H<sub>19</sub>L<sub>96</sub>, Giza 111, and Crawford were distributed in randomized complete blocks design with three replications. Soybean genotypes differed significantly for cotton leafworm at the 6<sup>th</sup>, 7<sup>th</sup>, and 8<sup>th</sup> week from sowing. Low values of cotton leafworm assemblages were recorded for H<sub>113</sub>, H<sub>4</sub>L<sub>4</sub>, H<sub>15</sub>L<sub>17</sub>, Giza 111, and H<sub>129</sub>. Low percentages of the larval survival number and weight, as well as the number of the survival of pupa were recorded by feeding on leaves of genotypes H<sub>4</sub>F<sub>4</sub>, H<sub>15</sub>L<sub>17</sub>, and Giza 111 under laboratory conditions. There were significant differences among the studied genotypes in most yield attributes in both seasons. Soybean genotypes H<sub>15</sub>L<sub>17</sub>, Giza 111, H<sub>113</sub>, H<sub>129</sub>, H<sub>19</sub>L<sub>96</sub>, and H<sub>4</sub>L<sub>4 </sub>gave higher seed yield per ha, meanwhile soybean genotypes H<sub>155</sub>, H<sub>19</sub>L<sub>96</sub>, H<sub>30</sub>, Giza 111, and H<sub>15</sub>L<sub>17</sub> had higher seed oil content than the other genotypes in both seasons. The number and weight of larvae surviving, as well as the number of pupa survival, were negatively correlated with leaf total phenols and seed oil content. It can be concluded that soybean genotypes H<sub>15</sub>L<sub>17</sub>, H<sub>4</sub>L<sub>4</sub>, and Giza 111 are promising genotypes with desirable seed oil content for tolerating cotton leafworm infestation in breeding programs.展开更多
Soybean genotypes show diverse physiological responses to drought, but specific physiological traits that can be used to evaluate drought tolerance have not been identified. In the present study we investigated physio...Soybean genotypes show diverse physiological responses to drought, but specific physiological traits that can be used to evaluate drought tolerance have not been identified. In the present study we investigated physiological traits of soybean genotypes under progressive soil drying and rewetting, using a treatment mimicking field conditions.After a preliminary study with eight soybean genotypes, two drought-tolerant genotypes and one susceptible genotype were grown in the greenhouse and subjected to water restriction. Leaf expansion rate, gas exchange, water relation parameters, total chlorophyll(Chl), proline contents of leaves, and root xylem p H were monitored in a time course, and plant growth and root traits were measured at the end of the stress cycle. Drought-tolerant genotypes maintained higher leaf expansion rate, net photosynthetic rate(Pn), Chl content,instantaneous water use efficiency(WUEi), % relative water content(RWC), water potential(ψw), and turgor potential(ψp) during progressive soil drying and subsequent rewetting than the susceptible genotypes. By contrast, stomatal conductance(gs) and transpiration rate(Tr)of tolerant genotypes declined faster owing to dehydration and recovered more sharply after rehydration than the same parameters in susceptible ones. Water stress caused a significant increase in leaf proline level and root xylem sap p H of both genotypes but tolerant genotypes recovered to pre-stress levels more quickly after rehydration. Tolerant genotypes also produced longer roots with higher dry mass than susceptible genotypes. We conclude that rapid perception and adjustment in response to soil drying and rewetting as well as the maintenance of relatively high Pn, %RWC, and root growth constitute the mechanisms by which drought-tolerant soybean genotypes cope with water stress.展开更多
The peculiarities of leaf carbon dioxide gas exchange in soybean genotypes grown in field over a large area and contrasting in duration of vegetation, photosynthetic traits and productivity were studied. Varietal diff...The peculiarities of leaf carbon dioxide gas exchange in soybean genotypes grown in field over a large area and contrasting in duration of vegetation, photosynthetic traits and productivity were studied. Varietal differences in the daily and ontogenetic changes in photosynthesis and photorespiration were identified. It was established that the period of the high activity of photosynthetic apparatus in high productive soybean genotypes lasts for a longer time. The photosynthetic rate and the rate of CO2 release in light due to photorespiration are higher in high productive genotypes. A value of photorespiration in contrasting soybean genotypes constitutes about 28% - 35% of photosynthetic rate. The ratio of gross photosynthesis to photorespiration in genotypes with different productivity is constant enough during ontogenesis, indicating a direct positive correlation between gross photosynthesis and photorespiration. Therefore, contrary to conception arisen during many years on the waste-fulness of photorespiration, taking into account the versatile investigations on different aspects of photo-respiration, it was proved that photorespiration is one of the evolutionarily developed vital metabolic processes in plants and the attempts to reduce this process with the purpose of increasing the crop productivity are inconsistent.展开更多
The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid(ABA) application during progressive soil drying at seed...The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid(ABA) application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVC tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance(g_s), leaf water potential(ψ_w), and relative water content of leaves(%RWC) declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype(C12) responded more rapidly than a drought-susceptible genotype(C08) after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher %RWC and ψwin the drought-tolerant than in the drought-susceptible genotype. Compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.展开更多
文摘目前人们仍不清楚温度是如何影响发育中的大豆（Glycine max L．）种子蛋白质和脂肪积累过程以及基因型不同的大豆是否对温度具有相同的反应。研究拟通过对3个基因型大豆在不同温度处理下，种子发育过程中的蛋白质和脂肪的积累模式研究，以了解温度对种子组分的调节机理。3个基因型大豆品种（Evans，PI132．217，和Proto）种子盆栽在温度为27／20％（中温）的生长箱中生长到开花。在开花后第10天，将其中的一个生长箱的温度调节到35／27℃（高温）；另一个调到20／12℃（低温）。生长在高温和中温条件下的大豆，在开花的第21天开始收集豆荚，每3d取1次样。生长在低温条件下的大豆，在开花的第25天开始收集豆荚，每5d取1次样。结果表明，3个基因型大豆种子均在高温下生长快，成熟早，在中温下生长速率最大，低温下生长速率低但种子生长期延长。当种子获得60％-70％总干重时种子脂肪含量达到最大（中温），高温使其提前出现，低温则被推后。在低温下，种子中蛋白质和脂肪两者积累模式相同，但蛋白质积累速率低。在高温和中温条件下，种子蛋白质和脂肪的积累模式不同。在种子获得60％～70％的总干重之前，蛋白质和脂肪积累模式相同，但在种子获得60％～70％的总干重之后，蛋白质积累呈上升趋势，而脂肪积累停止或下降。同时在种子发育的晚期伴随着蛋白质含量增加，淀粉和蔗糖含量快速下降。虽然3个基因型大豆种子的蛋白质和脂肪积累模式均明显受温度影响，但在不同温度条件下和不同生长阶段中高蛋白质品种Proto和PI132．217（蛋白质稳定型）蛋白质含量总是高于低蛋白质品种Evans，而且两者差异显著。这一研究表明温度不能改变品种在蛋白质和脂肪合成上的遗传特性。遗传育种在提高大豆种子蛋白质含量上仍起�
基金the Key Project of Knowledge Innovation Engineering of the Chinese Academy of Sciences(CAS),China(KSCX2-YW-N-43-05)
文摘A glasshouse study compared the growth and phosphorus （P） efficiency of 96 genotypes of soybean [Glycine max （L.） Merrill] in a P-deficient soil. The soybean genotypes differed greatly in growth, nodulation and P uptake after growing in the soil for 45 days, with shoot biomass ranging from 0.91 to 1.75 g per plant. The application of P improved biomass production, nodulation and P uptake and decreased root to shoot ratio, root length and surface area and P utilization efficiency. The 96 soybean genotypes were divided into 3 categories in P efficiency using the principal component analysis and cluster analysis, and 4 categories according to F values in combination with growth potentials. The Pefficient genotypes were associated with high biomass production, root to shoot ratio, root length and surface area and P uptake but low shoot to root P concentration ratio under P deficiency. The results indicate that there is a substantial genotypic variation in P efficiency in existing germplasm, and that P efficiency was correlated positively with dry weights of shoots and roots, ratio of root to shoot dry weight, root length and surface area, root P content and total P uptake. The shoot dry weight under P deficiency and relative shoot dry weight （deficient P/adequate P supply） are effective and simple indicators for screening P-efficient genotypes at the seedling stage.
文摘A two-year study was carried out in Giza Agricultural Experiments and Research Station, Agricultural Research Center (ARC), Giza, Egypt in the 2020 and 2021 summer seasons to evaluate the relative tolerance of ten soybean genotypes for cotton leafworm infestation under field conditions. Soybean genotypes H<sub>11</sub>L<sub>145</sub>, H<sub>155</sub>, H<sub>113</sub>, H<sub>4</sub>L<sub>4</sub>, H<sub>15</sub>L<sub>17</sub>, H<sub>129</sub>, H<sub>30</sub>, H<sub>19</sub>L<sub>96</sub>, Giza 111, and Crawford were distributed in randomized complete blocks design with three replications. Soybean genotypes differed significantly for cotton leafworm at the 6<sup>th</sup>, 7<sup>th</sup>, and 8<sup>th</sup> week from sowing. Low values of cotton leafworm assemblages were recorded for H<sub>113</sub>, H<sub>4</sub>L<sub>4</sub>, H<sub>15</sub>L<sub>17</sub>, Giza 111, and H<sub>129</sub>. Low percentages of the larval survival number and weight, as well as the number of the survival of pupa were recorded by feeding on leaves of genotypes H<sub>4</sub>F<sub>4</sub>, H<sub>15</sub>L<sub>17</sub>, and Giza 111 under laboratory conditions. There were significant differences among the studied genotypes in most yield attributes in both seasons. Soybean genotypes H<sub>15</sub>L<sub>17</sub>, Giza 111, H<sub>113</sub>, H<sub>129</sub>, H<sub>19</sub>L<sub>96</sub>, and H<sub>4</sub>L<sub>4 </sub>gave higher seed yield per ha, meanwhile soybean genotypes H<sub>155</sub>, H<sub>19</sub>L<sub>96</sub>, H<sub>30</sub>, Giza 111, and H<sub>15</sub>L<sub>17</sub> had higher seed oil content than the other genotypes in both seasons. The number and weight of larvae surviving, as well as the number of pupa survival, were negatively correlated with leaf total phenols and seed oil content. It can be concluded that soybean genotypes H<sub>15</sub>L<sub>17</sub>, H<sub>4</sub>L<sub>4</sub>, and Giza 111 are promising genotypes with desirable seed oil content for tolerating cotton leafworm infestation in breeding programs.
基金supported by the Hong Kong RGC Collaborative Research Fund (CUHK3/CRF/ 11G) to Prof. H.-M. Lam. and J.H. Zhang
文摘Soybean genotypes show diverse physiological responses to drought, but specific physiological traits that can be used to evaluate drought tolerance have not been identified. In the present study we investigated physiological traits of soybean genotypes under progressive soil drying and rewetting, using a treatment mimicking field conditions.After a preliminary study with eight soybean genotypes, two drought-tolerant genotypes and one susceptible genotype were grown in the greenhouse and subjected to water restriction. Leaf expansion rate, gas exchange, water relation parameters, total chlorophyll(Chl), proline contents of leaves, and root xylem p H were monitored in a time course, and plant growth and root traits were measured at the end of the stress cycle. Drought-tolerant genotypes maintained higher leaf expansion rate, net photosynthetic rate(Pn), Chl content,instantaneous water use efficiency(WUEi), % relative water content(RWC), water potential(ψw), and turgor potential(ψp) during progressive soil drying and subsequent rewetting than the susceptible genotypes. By contrast, stomatal conductance(gs) and transpiration rate(Tr)of tolerant genotypes declined faster owing to dehydration and recovered more sharply after rehydration than the same parameters in susceptible ones. Water stress caused a significant increase in leaf proline level and root xylem sap p H of both genotypes but tolerant genotypes recovered to pre-stress levels more quickly after rehydration. Tolerant genotypes also produced longer roots with higher dry mass than susceptible genotypes. We conclude that rapid perception and adjustment in response to soil drying and rewetting as well as the maintenance of relatively high Pn, %RWC, and root growth constitute the mechanisms by which drought-tolerant soybean genotypes cope with water stress.
文摘The peculiarities of leaf carbon dioxide gas exchange in soybean genotypes grown in field over a large area and contrasting in duration of vegetation, photosynthetic traits and productivity were studied. Varietal differences in the daily and ontogenetic changes in photosynthesis and photorespiration were identified. It was established that the period of the high activity of photosynthetic apparatus in high productive soybean genotypes lasts for a longer time. The photosynthetic rate and the rate of CO2 release in light due to photorespiration are higher in high productive genotypes. A value of photorespiration in contrasting soybean genotypes constitutes about 28% - 35% of photosynthetic rate. The ratio of gross photosynthesis to photorespiration in genotypes with different productivity is constant enough during ontogenesis, indicating a direct positive correlation between gross photosynthesis and photorespiration. Therefore, contrary to conception arisen during many years on the waste-fulness of photorespiration, taking into account the versatile investigations on different aspects of photo-respiration, it was proved that photorespiration is one of the evolutionarily developed vital metabolic processes in plants and the attempts to reduce this process with the purpose of increasing the crop productivity are inconsistent.
基金supported by the Hong Kong RGC Collaborative Research Fund(CUHK3/CRF/11G)to Prof.Hon-Ming Lam and Prof.Jianhua Zhang
文摘The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid(ABA) application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVC tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance(g_s), leaf water potential(ψ_w), and relative water content of leaves(%RWC) declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype(C12) responded more rapidly than a drought-susceptible genotype(C08) after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher %RWC and ψwin the drought-tolerant than in the drought-susceptible genotype. Compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.
