Tea (Camellia sinensis) is one of the most important economic crops. Being perennial in nature, tea plant often experiences natural drought, which affects its growth and productivity. The present investigation was und...Tea (Camellia sinensis) is one of the most important economic crops. Being perennial in nature, tea plant often experiences natural drought, which affects its growth and productivity. The present investigation was undertaken to understand the mechanism of post-drought stress recovery on rehydration and the effect of nutrients in the recovery process of the selected clones of Camellia sinensis L. (TV-1, TV-20, TV-29 & TV-30). The results demonstrated that decrease in relative water content (RWC), dry mass of leaf and antioxidants like-ascorbate and glutathione in all the tested clones, as a result of imposed water stress, which caused damage was not permanent. Increase in phenolic content with decrease in O2-, H2O2 and lipid peroxidation was indication of the recovery of stress induced oxidative damage following the post stress rehydration. Further, the post drought recovery was enhanced by foliar spray of K, Ca, Mn & B. Differential activities of enzymes like SOD, CAT, POX, GR and PPO in response to foliar spray of nutrients in rehydrated plant improved the recovery process. The present study reveals that the tested nutrients (K, Ca, Mn & B) showed some positive response in influencing growth and antioxidative responses during post drought recovery process, where K and Ca showed comparatively better effect in improving post drought recovery potential in tea plant.展开更多
With the support by the National Natural Science Foundation of China,the research team led by Prof.Liu HongYan(刘鸿雁)at the College of Urban and Environmental Sciences and MOE laboratory for Earth Surface Processes,P...With the support by the National Natural Science Foundation of China,the research team led by Prof.Liu HongYan(刘鸿雁)at the College of Urban and Environmental Sciences and MOE laboratory for Earth Surface Processes,Peking University,reported the compensation effect of extreme wetness for the growth loss in dry forests,which was published in Nature Communications(2019,doi:10.1038/s41467-018-08229-z).展开更多
Sorghum (Sorghum bicolour (L.) Moench) grown under rain-fed conditions is usually affected by drought stress at different stages, resulting in reduced yield. The assessment of variation in morpho-physiological traits ...Sorghum (Sorghum bicolour (L.) Moench) grown under rain-fed conditions is usually affected by drought stress at different stages, resulting in reduced yield. The assessment of variation in morpho-physiological traits contributing towards drought tolerance at these stages is of vital importance. This study was conducted using a split plot design with three replications to evaluate 25 sorghum accessions at post flowering stage under well watered and drought stress conditions at Hamelmalo Agricultural College. The data of 14 different morpho-physiological traits were subjected to analysis of variance, estimation of genetic variability and heritability and principal component analysis. We analyzed variance for seedling vigor, number of leaves, leaf area, stay-green, peduncle exsertion, panicle length and width, plant height, days to flowering and maturity, grain yield, biomass and harvest index under drought stress and irrigated conditions. The results showed that genotypic differences were significant at P 1 explaining 74.6% of the total variation with grain yield, biomass, stay-green, leaf area, peduncle exsertion and days to flowering and maturity being the most important characters in PC1 and PC2. This research demonstrated high diversity for the characters studied. Moreover, the result showed that drought stress reduced the yield of some genotypes, though others were tolerant to drought. Accessions EG 885, EG 469, EG 481, EG 849, Hamelmalo, EG 836 and EG 711 were identified as superior for post-flowering drought tolerance and could be used by breeders in improvement programs.展开更多
Drought stress at the reproductive stage causes severe damage to productivity of wheat. However, little is known about the metabolites associated with drought tolerance. The objectives of this study were to elucidate ...Drought stress at the reproductive stage causes severe damage to productivity of wheat. However, little is known about the metabolites associated with drought tolerance. The objectives of this study were to elucidate changes in metabolite levels in wheat under drought, and to identify potential metabolites associated with drought stress through untargeted metabolomic profiling using a liquid chromatography-high resolution mass spectrometry (LC-HRMS)-based technique called Isotopic Ratio Outlier Analysis. Metabolomic analysis was performed on flag leaves of drought-stressed and control (well-watered) plants after 18 days of post-anthesis drought stress at three-hour intervals over a 24-hour period. Out of 723 peaks detected in leaves, 221 were identified as known metabolites. Sixty known metabolites were identified as important metabolites by 3 different methods, PLS-DA, RF and SAM. The most pronounced accumulation due to drought stress was demonstrated by tryptophan, proline, pipecolate and linamarin, whereas the most pronounced decrease was demonstrated by serine, trehalose, N-acetyl-glutamic acid, DIBOA-glucoside etc. Three different patterns of metabolite accumulation were observed over 24-hour period. The increased accumulated metabolites remained higher during all 8 time points in drought stressed leaves. On the contrary, metabolites that showed decreased level remained significantly lower during all or the most time points. However, the levels of some decreased metabolites were lower during the day, but higher during night in drought stressed leaves. Both univariate and multivariate analyses predicted that N-acetyl-glutamic acid, proline, pipecolate, linamarin, tryptophan, and DIBOA-glucoside could be potential metabolite biomarkers, and their levels could serve as indicators of drought tolerance in wheat.展开更多
Cowpea [(Vigna unguiculata (L.)] is one of the most important arid legumes cultivated for pulse and forage production. However, in cowpea, not much is known about the base index selection method in breeding for drough...Cowpea [(Vigna unguiculata (L.)] is one of the most important arid legumes cultivated for pulse and forage production. However, in cowpea, not much is known about the base index selection method in breeding for drought tolerance. Consequently, the present study has been conducted to: 1) evaluate the yield performance of cowpea genotypes under artificial drought and well-watered condition;2) develop a base index using multiple traits for ranking genotype performance. The experiment was a 25 × 2 factorial laid out in a Randomized Complete Block Design (RCBD) with three replications. The experiment was carried out in the screen house at the Department of Horticulture at KNUST. The result showed that KPR1-96-73, Simbo, CZ06-4-16, Wilibaly and Agyenkwa were high yielding in well-water condition while Ghana Shoba, Sangaraka, NKetewade, Ghana-Shoni and Korobalen were high yielding genotypes in water stress condition. The average yield reduction was 60.6% for grain respectively. The biplot displays revealed four groups among the genotypes tested which was based on their yielding capacity and drought tolerance. In cluster B high yielding and drought tolerant genotypes were identified, high yielding and drought susceptible have been identified in cluster A, low yielding and drought tolerant in cluster D, and lastly low yielding and drought susceptible in cluster C. Genotypes in cluster B, were the best due to the fact that it combines high yield and tolerance to drought. They were Ghana Shoni, Nketewade, Sangaraka and Ghana shoba. These genotypes might be suitably employed in further drought tolerance breeding program of cowpea.展开更多
文摘Tea (Camellia sinensis) is one of the most important economic crops. Being perennial in nature, tea plant often experiences natural drought, which affects its growth and productivity. The present investigation was undertaken to understand the mechanism of post-drought stress recovery on rehydration and the effect of nutrients in the recovery process of the selected clones of Camellia sinensis L. (TV-1, TV-20, TV-29 & TV-30). The results demonstrated that decrease in relative water content (RWC), dry mass of leaf and antioxidants like-ascorbate and glutathione in all the tested clones, as a result of imposed water stress, which caused damage was not permanent. Increase in phenolic content with decrease in O2-, H2O2 and lipid peroxidation was indication of the recovery of stress induced oxidative damage following the post stress rehydration. Further, the post drought recovery was enhanced by foliar spray of K, Ca, Mn & B. Differential activities of enzymes like SOD, CAT, POX, GR and PPO in response to foliar spray of nutrients in rehydrated plant improved the recovery process. The present study reveals that the tested nutrients (K, Ca, Mn & B) showed some positive response in influencing growth and antioxidative responses during post drought recovery process, where K and Ca showed comparatively better effect in improving post drought recovery potential in tea plant.
文摘With the support by the National Natural Science Foundation of China,the research team led by Prof.Liu HongYan(刘鸿雁)at the College of Urban and Environmental Sciences and MOE laboratory for Earth Surface Processes,Peking University,reported the compensation effect of extreme wetness for the growth loss in dry forests,which was published in Nature Communications(2019,doi:10.1038/s41467-018-08229-z).
文摘Sorghum (Sorghum bicolour (L.) Moench) grown under rain-fed conditions is usually affected by drought stress at different stages, resulting in reduced yield. The assessment of variation in morpho-physiological traits contributing towards drought tolerance at these stages is of vital importance. This study was conducted using a split plot design with three replications to evaluate 25 sorghum accessions at post flowering stage under well watered and drought stress conditions at Hamelmalo Agricultural College. The data of 14 different morpho-physiological traits were subjected to analysis of variance, estimation of genetic variability and heritability and principal component analysis. We analyzed variance for seedling vigor, number of leaves, leaf area, stay-green, peduncle exsertion, panicle length and width, plant height, days to flowering and maturity, grain yield, biomass and harvest index under drought stress and irrigated conditions. The results showed that genotypic differences were significant at P 1 explaining 74.6% of the total variation with grain yield, biomass, stay-green, leaf area, peduncle exsertion and days to flowering and maturity being the most important characters in PC1 and PC2. This research demonstrated high diversity for the characters studied. Moreover, the result showed that drought stress reduced the yield of some genotypes, though others were tolerant to drought. Accessions EG 885, EG 469, EG 481, EG 849, Hamelmalo, EG 836 and EG 711 were identified as superior for post-flowering drought tolerance and could be used by breeders in improvement programs.
文摘Drought stress at the reproductive stage causes severe damage to productivity of wheat. However, little is known about the metabolites associated with drought tolerance. The objectives of this study were to elucidate changes in metabolite levels in wheat under drought, and to identify potential metabolites associated with drought stress through untargeted metabolomic profiling using a liquid chromatography-high resolution mass spectrometry (LC-HRMS)-based technique called Isotopic Ratio Outlier Analysis. Metabolomic analysis was performed on flag leaves of drought-stressed and control (well-watered) plants after 18 days of post-anthesis drought stress at three-hour intervals over a 24-hour period. Out of 723 peaks detected in leaves, 221 were identified as known metabolites. Sixty known metabolites were identified as important metabolites by 3 different methods, PLS-DA, RF and SAM. The most pronounced accumulation due to drought stress was demonstrated by tryptophan, proline, pipecolate and linamarin, whereas the most pronounced decrease was demonstrated by serine, trehalose, N-acetyl-glutamic acid, DIBOA-glucoside etc. Three different patterns of metabolite accumulation were observed over 24-hour period. The increased accumulated metabolites remained higher during all 8 time points in drought stressed leaves. On the contrary, metabolites that showed decreased level remained significantly lower during all or the most time points. However, the levels of some decreased metabolites were lower during the day, but higher during night in drought stressed leaves. Both univariate and multivariate analyses predicted that N-acetyl-glutamic acid, proline, pipecolate, linamarin, tryptophan, and DIBOA-glucoside could be potential metabolite biomarkers, and their levels could serve as indicators of drought tolerance in wheat.
文摘Cowpea [(Vigna unguiculata (L.)] is one of the most important arid legumes cultivated for pulse and forage production. However, in cowpea, not much is known about the base index selection method in breeding for drought tolerance. Consequently, the present study has been conducted to: 1) evaluate the yield performance of cowpea genotypes under artificial drought and well-watered condition;2) develop a base index using multiple traits for ranking genotype performance. The experiment was a 25 × 2 factorial laid out in a Randomized Complete Block Design (RCBD) with three replications. The experiment was carried out in the screen house at the Department of Horticulture at KNUST. The result showed that KPR1-96-73, Simbo, CZ06-4-16, Wilibaly and Agyenkwa were high yielding in well-water condition while Ghana Shoba, Sangaraka, NKetewade, Ghana-Shoni and Korobalen were high yielding genotypes in water stress condition. The average yield reduction was 60.6% for grain respectively. The biplot displays revealed four groups among the genotypes tested which was based on their yielding capacity and drought tolerance. In cluster B high yielding and drought tolerant genotypes were identified, high yielding and drought susceptible have been identified in cluster A, low yielding and drought tolerant in cluster D, and lastly low yielding and drought susceptible in cluster C. Genotypes in cluster B, were the best due to the fact that it combines high yield and tolerance to drought. They were Ghana Shoni, Nketewade, Sangaraka and Ghana shoba. These genotypes might be suitably employed in further drought tolerance breeding program of cowpea.
