In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selec...In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selected, and the their change laws of cold tolerance under normal moisture condition and drought stress condition. The results showed that under drought condition, the cold tolerance of wheat in various growth stages was remarkably lower than that under nondrought condition, and the decreasing amplitudes were the largest in overwintering stage with an average of 4.91 ℃, the smallest in regreening stage, and in the middle in the jointing stage. Under non-drought condition, the cold tolerance of semi- winter varieties in various growth stages was better than that of spring varieties, there were significant differences between different varieties, and the cold tolerance of all varieties in overwintering stage was improved compared with before winter, and rapidly decreased after overwintering. Semiwinter varieties showed cold tolerance remarkably enhanced in overwintering stage, and the cold tolerance of spring varieties was also improved to a certain degree.展开更多
[Objective] The aim was to explore the response of different maize vari- eties in Guangxi to drought stress and re-watering at tasseling stage, so as to pro- vide reference for study on drought resistance mechanism, b...[Objective] The aim was to explore the response of different maize vari- eties in Guangxi to drought stress and re-watering at tasseling stage, so as to pro- vide reference for study on drought resistance mechanism, breeding of drought-re- sistant varieties and selection of maize varieties for fall sowing. [Method] At the tasseling stage, total five degrees of drought stress （4, 8, 12, 16 and 20 d） and corresponding re-watering after drought stress were simulated by a tub planting ex- periment in greenhouse for five different maize varieties （Guidan 0810, Dika 008, Zhengda 619, Chenyu 969, Guidan 901）. Normal watering was set as the control. Sampling was carried out on Day 1 after drought stress and on Day 15 after re- watering, and the secondary root number, maximum root length, green leaf number, root dry weight and shoot dry weight were measured. At the harvest time, the ear yield per plant was measured. With yield as the basis, the drought resistance coef- ficient and drought resistance index were calculated. Cluster analysis was conducted for drought resistance coefficient. [Result] The shoot dry weight, root dry weight, secondary root number, maximum root length and green leaf number of maize in the treatment groups decreased compared with those in the control group. The ratio of each index between the treatment and control groups declined with the extension of drought stress. After re-watering, the re-growth amount of each index all de- creased as the stress time prolonged. Post-re-watering over compensation effect oc- curred in none of the indices except the maximum root length, after 4 days of drought stress. Under drought stress, the reductions of all the indices of Guidan 0810, Dika 008 and Zhengda 619 were smaller than those of Chenyu 969 and Guidan 901. After re-watering, the re-growth abilities of Guidan 0810, Dika 008 and Zhengda 619 were stronger than those of Chenyu 969 and Guidan 901. The drought resistance coefficients and drought resistance indexes of Guidan 0810, Dika 008 and Zhengda 619 were all greater than those of Chenyu 969 and Guidan 901. The results of drought resistance coefficient cluster analysis showed that the five maize varieties were classified into two groups： Guidan 0810, Dika 008 and Zheng- da 619 had strong drought resistance, while Guidan 901 and Chenyu 969 had weak drought resistance. [Conclusion] The root and shoot growth of Guidan 0810, Dika 008 and Zhengda 619 was slightly affected by drought stress during the tasseling period, and they restored the growth rapidly after re-watering, thus ensuring high biomass and yield. Therefore, Guidan 0810, Dika 008 and Zhengda 619 can be promoted as drought-resistant autumn maize varieties in Guangxi.展开更多
[Objective] Jishu 21 with strong drought tolerance and Jizishu 1 with weak drought tolerance were chosen to reveal antioxidant characteristics in seedling roots of sweetpotato with different drought tolerance. [Method...[Objective] Jishu 21 with strong drought tolerance and Jizishu 1 with weak drought tolerance were chosen to reveal antioxidant characteristics in seedling roots of sweetpotato with different drought tolerance. [Method] Active oxygen, antioxidant substances and antioxidant enzymes in seedling roots of sweetpotato with different drought tolerance were analyzed by hydroponics with PEG-6000 for simulating drought stress in the experiment. [Result] The results showed that under drought stress, H202 content and formation rate of 02_ in seedling roots of Jizishul were higher than Jishu 21 by 1.9% and 102.6%, respectively, the contents of Vc in seed- ing roots of Jizishu 1 and Jizishu 1 increased by 25.3% and 81.1%, respectively, and the contents of polyphenols increased by 24.8% and 37.6% in the two vari- eties, respectively. The increase amplitudes of Jizishu 1 were higher than Jishu 21 in the above indexes. Antioxidant enzyme activities were higher in seedling roots of Jisl^u 21 and Jizishul under drought stress than normal treatments; and among them, POD activity was the highest, while PPO activity was the lowest in all an- tioxidant enzymes. The increases of SOD, POD, APX and PPO activities in Jishu 21 were twice of those in Jizishul. The bands of SOD3, POD2, CAT1, APX2 and PPO2 changed obviously between the drought treatments of the two varieties. [Con- clusion] In conclusion, stronger drought tolerance in sweetpotato results in lower in- crease amplitudes of H202 content, formation rate of 02- and contents of Vc and polyphenols under drought stress, and the activities of antioxidant enzymes are stronger in seeding roots under drought stress; and the differences in antioxidant enzymes are mainly related to the changes of isoenzymes including SOD3, POD2, CAT1. APX2 and PPO2.展开更多
A simulation experiment on the responses of maize (Zea mays L.) from the third leaf stage to maturity for different soil water levels (well-watered, moderately stressed, and severely stressed) was conducted by control...A simulation experiment on the responses of maize (Zea mays L.) from the third leaf stage to maturity for different soil water levels (well-watered, moderately stressed, and severely stressed) was conducted by controlling irrigation and using a mobile rain shelter in a neutral loam, meadow soil to determine the effects on leaf water status, membrane permeability and enzymatic antioxidant system for different growth stages. The results indicated that drought stress relied on drought intensity and duration, with more severe drought stress creating more serious effects on maize. Compared with well-watered conditions, during the silking and blister stages moderate stress did not significantly change the relative water content (RWC) and did change significantly the relative conductivity (RC) (P < 0.05) of the leaves; however, severe stress did significantly decrease (P < 0.01) the leaf RWC and increase (P < 0.01) membrane permeability (leaf relative conductivity). Furthermore, under severe drought stress antioxidant enzyme activities declined significantly (P < 0.01) in later stages, namely for superoxide dismutase (SOD) the tasseling and blister stages, for peroxidase (POD) the milk stage, and for catalase (CAT) during the tasseling, blister, and milk stages. Meanwhile, membrane lipid peroxidation (measured as malondialdehyde content) significantly increased (P < 0.01) in all stages.展开更多
This research presents complete phenolic compounds and biological activity of Tamarix pauciovulata J. Gay, an endemic Saharan species. The antioxidant assays revealed that crude extract showed strong DPPH scavenging a...This research presents complete phenolic compounds and biological activity of Tamarix pauciovulata J. Gay, an endemic Saharan species. The antioxidant assays revealed that crude extract showed strong DPPH scavenging activity （IC50 = 49.357 μg/mL） but in reducing power and hydrogen peroxide scavenging activity, butanolic and ethyl acetate fractions have a potent ferrous ion-chelating ability in particularly the butanolic fraction （63.18% reduced power at 50 μg/mL） and a powerful scavenging activity on hydrogen peroxide in particularly ethyl acetate fraction （IC50 = 0.205 μg/mL）. The phenolic compounds of Tamarix pauciovulata leaves were analyzed by HPLC-UV. The major phenolic of leaf extracts are syringic acid （1.07 g/100g）, quercetin （34.1 mg/100g）, kaempferol （5.77 mg/100g）, isorhamnetin （5 mg/100g）. Others phenols were identified such as isoquercetin, catechin, epicatechin and its derivatives. Results indicated that the leaves extracts from Tamarix pauciovulata have great capacities to prevent diseases caused by the overproduction of radicals and can become important source of dietary compounds with health protective potential.展开更多
Aims Cunninghamia lanceolata is one of the most important coniferous species in southern China,but its high sensitivity to drought restricts its expansion.Understanding the intraspecific variation of physiological res...Aims Cunninghamia lanceolata is one of the most important coniferous species in southern China,but its high sensitivity to drought restricts its expansion.Understanding the intraspecific variation of physiological responses to drought can help us manage this plantation better.Methods We selected 3-year-old seedlings of C.lanceolata,which originated from the low precipitation(LP),middle precipitation(MP)and high precipitation(HP)habitats,respectively.Seedlings were grown under drought stress(20%of soil volumetric water content)for 40 days.The ecophysiological responses and adaptive strategies with different drought tolerance were investigated.Important Findings LP provenance possessed the best tolerance to drought stress,suggesting that considerably increased carbohydrates and nitrogen-containing compounds as osmotic protective materials,which were driven by fast carbon and nitrogen metabolisms.In addition,the highest peroxidase activity could effectively eliminate hydrogen peroxide in drought-stressed LP provenance.The MP provenance reserved a large amount of non-structural carbohydrates,which may act as a certain buffer for encountering drought stress.Importantly,timely closure of stomata to reduce needle transpiration when encountering a water deficiency would help them adapt to long-term drought.MP provenance adopted a conservative water-saving strategy.However,HP provenance regulated root growth(increased root/shoot ratio)and reduced penetration potential to help them absorb water.The different strategies among provenances may be related to the long-term domestication of the geographical environments.Therefore,our results underline the importance of provenance-specific responses to drought stress.It is highly significant to accelerate the selection of drought-resistant germplasms and to cultivate high-yield plantations in the future.展开更多
文摘In order to study the change laws of cold tolerance in wheat under drought stress, 11 wheat varieties planted in Huang-Huai wheat area and one variety representative in middle-lower Yangtze River wheat area were selected, and the their change laws of cold tolerance under normal moisture condition and drought stress condition. The results showed that under drought condition, the cold tolerance of wheat in various growth stages was remarkably lower than that under nondrought condition, and the decreasing amplitudes were the largest in overwintering stage with an average of 4.91 ℃, the smallest in regreening stage, and in the middle in the jointing stage. Under non-drought condition, the cold tolerance of semi- winter varieties in various growth stages was better than that of spring varieties, there were significant differences between different varieties, and the cold tolerance of all varieties in overwintering stage was improved compared with before winter, and rapidly decreased after overwintering. Semiwinter varieties showed cold tolerance remarkably enhanced in overwintering stage, and the cold tolerance of spring varieties was also improved to a certain degree.
基金Supported by National High Technology Research and Development Program of China(2011AA10A103)National Key Technology Research and Development Program of China(2011BAD35B01)+1 种基金Key Research & Development Project of Guangxi Zhuang Autonomous Region(GK AB16380133)Science and Technology Development Fund of Guangxi Academy of Agricultural Sciences(GNK 2015YT24)~~
文摘[Objective] The aim was to explore the response of different maize vari- eties in Guangxi to drought stress and re-watering at tasseling stage, so as to pro- vide reference for study on drought resistance mechanism, breeding of drought-re- sistant varieties and selection of maize varieties for fall sowing. [Method] At the tasseling stage, total five degrees of drought stress （4, 8, 12, 16 and 20 d） and corresponding re-watering after drought stress were simulated by a tub planting ex- periment in greenhouse for five different maize varieties （Guidan 0810, Dika 008, Zhengda 619, Chenyu 969, Guidan 901）. Normal watering was set as the control. Sampling was carried out on Day 1 after drought stress and on Day 15 after re- watering, and the secondary root number, maximum root length, green leaf number, root dry weight and shoot dry weight were measured. At the harvest time, the ear yield per plant was measured. With yield as the basis, the drought resistance coef- ficient and drought resistance index were calculated. Cluster analysis was conducted for drought resistance coefficient. [Result] The shoot dry weight, root dry weight, secondary root number, maximum root length and green leaf number of maize in the treatment groups decreased compared with those in the control group. The ratio of each index between the treatment and control groups declined with the extension of drought stress. After re-watering, the re-growth amount of each index all de- creased as the stress time prolonged. Post-re-watering over compensation effect oc- curred in none of the indices except the maximum root length, after 4 days of drought stress. Under drought stress, the reductions of all the indices of Guidan 0810, Dika 008 and Zhengda 619 were smaller than those of Chenyu 969 and Guidan 901. After re-watering, the re-growth abilities of Guidan 0810, Dika 008 and Zhengda 619 were stronger than those of Chenyu 969 and Guidan 901. The drought resistance coefficients and drought resistance indexes of Guidan 0810, Dika 008 and Zhengda 619 were all greater than those of Chenyu 969 and Guidan 901. The results of drought resistance coefficient cluster analysis showed that the five maize varieties were classified into two groups： Guidan 0810, Dika 008 and Zheng- da 619 had strong drought resistance, while Guidan 901 and Chenyu 969 had weak drought resistance. [Conclusion] The root and shoot growth of Guidan 0810, Dika 008 and Zhengda 619 was slightly affected by drought stress during the tasseling period, and they restored the growth rapidly after re-watering, thus ensuring high biomass and yield. Therefore, Guidan 0810, Dika 008 and Zhengda 619 can be promoted as drought-resistant autumn maize varieties in Guangxi.
基金Supported by the Earmarked Fund for China Agriculture Research System(CARS-11-B-11)~~
文摘[Objective] Jishu 21 with strong drought tolerance and Jizishu 1 with weak drought tolerance were chosen to reveal antioxidant characteristics in seedling roots of sweetpotato with different drought tolerance. [Method] Active oxygen, antioxidant substances and antioxidant enzymes in seedling roots of sweetpotato with different drought tolerance were analyzed by hydroponics with PEG-6000 for simulating drought stress in the experiment. [Result] The results showed that under drought stress, H202 content and formation rate of 02_ in seedling roots of Jizishul were higher than Jishu 21 by 1.9% and 102.6%, respectively, the contents of Vc in seed- ing roots of Jizishu 1 and Jizishu 1 increased by 25.3% and 81.1%, respectively, and the contents of polyphenols increased by 24.8% and 37.6% in the two vari- eties, respectively. The increase amplitudes of Jizishu 1 were higher than Jishu 21 in the above indexes. Antioxidant enzyme activities were higher in seedling roots of Jisl^u 21 and Jizishul under drought stress than normal treatments; and among them, POD activity was the highest, while PPO activity was the lowest in all an- tioxidant enzymes. The increases of SOD, POD, APX and PPO activities in Jishu 21 were twice of those in Jizishul. The bands of SOD3, POD2, CAT1, APX2 and PPO2 changed obviously between the drought treatments of the two varieties. [Con- clusion] In conclusion, stronger drought tolerance in sweetpotato results in lower in- crease amplitudes of H202 content, formation rate of 02- and contents of Vc and polyphenols under drought stress, and the activities of antioxidant enzymes are stronger in seeding roots under drought stress; and the differences in antioxidant enzymes are mainly related to the changes of isoenzymes including SOD3, POD2, CAT1. APX2 and PPO2.
基金Project supported by the National Key Basic Research Support Foundation of China (No. G1999043407)the National Natural Science Foundation of China (No. 40231018)
文摘A simulation experiment on the responses of maize (Zea mays L.) from the third leaf stage to maturity for different soil water levels (well-watered, moderately stressed, and severely stressed) was conducted by controlling irrigation and using a mobile rain shelter in a neutral loam, meadow soil to determine the effects on leaf water status, membrane permeability and enzymatic antioxidant system for different growth stages. The results indicated that drought stress relied on drought intensity and duration, with more severe drought stress creating more serious effects on maize. Compared with well-watered conditions, during the silking and blister stages moderate stress did not significantly change the relative water content (RWC) and did change significantly the relative conductivity (RC) (P < 0.05) of the leaves; however, severe stress did significantly decrease (P < 0.01) the leaf RWC and increase (P < 0.01) membrane permeability (leaf relative conductivity). Furthermore, under severe drought stress antioxidant enzyme activities declined significantly (P < 0.01) in later stages, namely for superoxide dismutase (SOD) the tasseling and blister stages, for peroxidase (POD) the milk stage, and for catalase (CAT) during the tasseling, blister, and milk stages. Meanwhile, membrane lipid peroxidation (measured as malondialdehyde content) significantly increased (P < 0.01) in all stages.
文摘This research presents complete phenolic compounds and biological activity of Tamarix pauciovulata J. Gay, an endemic Saharan species. The antioxidant assays revealed that crude extract showed strong DPPH scavenging activity （IC50 = 49.357 μg/mL） but in reducing power and hydrogen peroxide scavenging activity, butanolic and ethyl acetate fractions have a potent ferrous ion-chelating ability in particularly the butanolic fraction （63.18% reduced power at 50 μg/mL） and a powerful scavenging activity on hydrogen peroxide in particularly ethyl acetate fraction （IC50 = 0.205 μg/mL）. The phenolic compounds of Tamarix pauciovulata leaves were analyzed by HPLC-UV. The major phenolic of leaf extracts are syringic acid （1.07 g/100g）, quercetin （34.1 mg/100g）, kaempferol （5.77 mg/100g）, isorhamnetin （5 mg/100g）. Others phenols were identified such as isoquercetin, catechin, epicatechin and its derivatives. Results indicated that the leaves extracts from Tamarix pauciovulata have great capacities to prevent diseases caused by the overproduction of radicals and can become important source of dietary compounds with health protective potential.
基金This work was supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0404)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA20020401)+1 种基金the State Key Research Development Program of China(2016YFD0600302-5)the Fundamental Research Funds for Central Universities。
文摘Aims Cunninghamia lanceolata is one of the most important coniferous species in southern China,but its high sensitivity to drought restricts its expansion.Understanding the intraspecific variation of physiological responses to drought can help us manage this plantation better.Methods We selected 3-year-old seedlings of C.lanceolata,which originated from the low precipitation(LP),middle precipitation(MP)and high precipitation(HP)habitats,respectively.Seedlings were grown under drought stress(20%of soil volumetric water content)for 40 days.The ecophysiological responses and adaptive strategies with different drought tolerance were investigated.Important Findings LP provenance possessed the best tolerance to drought stress,suggesting that considerably increased carbohydrates and nitrogen-containing compounds as osmotic protective materials,which were driven by fast carbon and nitrogen metabolisms.In addition,the highest peroxidase activity could effectively eliminate hydrogen peroxide in drought-stressed LP provenance.The MP provenance reserved a large amount of non-structural carbohydrates,which may act as a certain buffer for encountering drought stress.Importantly,timely closure of stomata to reduce needle transpiration when encountering a water deficiency would help them adapt to long-term drought.MP provenance adopted a conservative water-saving strategy.However,HP provenance regulated root growth(increased root/shoot ratio)and reduced penetration potential to help them absorb water.The different strategies among provenances may be related to the long-term domestication of the geographical environments.Therefore,our results underline the importance of provenance-specific responses to drought stress.It is highly significant to accelerate the selection of drought-resistant germplasms and to cultivate high-yield plantations in the future.
