PEG模拟干旱胁迫下苗期木薯的生长生理响应  

Growth and Physiological Response of Seedling Cassava under Drought Stress Simulated by PEG

作　　者：陈默 陈璐 黄晓雅 谢海弘 李双江 左紫琳 盛浩 宋勇[1,2,4,5,6] CHEN Mo;CHEN Lu;HUANG Xiaoya;XIE Haihong;LI Shuangjiang;ZUO Zilin;SHENG Hao;SONG Yong(Horticulture College of Hunan Agricultural University,Changsha 410128,China;Yuelushan Laboratory,Changsha 401128,China;College of Resources of Hunan Agricultural University,Changsha 410128,China;Engineering Research Center of Potato in Hunan Province,Changsha 410128,China;Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding,Ministry of Education,Changsha 410128,China;Key Laboratory for Vegetable Biology of Hunan Province,Changsha 410128,China)

机构地区：[1]湖南农业大学园艺学院,湖南长沙410128 [2]岳麓山实验室,湖南长沙401128 [3]湖南农业大学资源学院,湖南长沙410128 [4]湖南省马铃薯工程技术研究中心,湖南长沙410128 [5]园艺作物种质创新与新品种选育教育部工程研究中心,湖南长沙410128 [6]蔬菜生物学湖南省重点实验室,湖南长沙410128

出　　处：《云南农业大学学报（自然科学版）》2024年第4期15-22,共8页Journal of Yunnan Agricultural University:Natural Science

基　　金：财政部和农业农村部国家现代农业产业技术体系建设项目(CARS-11-HNSY)。

摘　　要：【目的】研究聚乙二醇(polyethylene glycol,PEG)模拟干旱胁迫对木薯生长生理的影响。【方法】以木薯品种NZ199为试验材料,将其根系浸入质量分数分别为0%、5%、10%、15%和20%的PEG溶液中,进行为期9 d的模拟干旱胁迫试验,并分别于第3、6、9天测量其生长、光合和生理各项指标。【结果】随着PEG质量分数的升高,同一时期NZ199的各项生长指标整体呈先升高后降低的趋势;净光合速率、气孔导度和蒸腾速率在低质量分数下被促进,而在高质量分数下受到抑制,处理前期(≤3 d)以10%PEG处理最高,后期(≥6 d)以5%PEG处理最高;可溶性蛋白含量呈先升高后降低的趋势,在10%PEG处理6和9 d时最高;15%和20%PEG处理的脯氨酸含量显著高于其他处理;过氧化物酶活性呈先升高后降低的趋势,以10%PEG处理6 d时最高;过氧化氢酶活性逐渐升高,以20%PEG处理9 d时最高;丙二醛含量逐渐增加,以20%PEG处理9 d时最高,表明木薯受到的胁迫最为严重。【结论】在NZ199苗期,适当的PEG质量分数和时间模拟干旱胁迫可以促进植株的光合作用,有利于积累同化物,但PEG质量分数过高会对植株产生反作用,叶片光合作用降低,脯氨酸含量、过氧化氢酶活性和丙二醛含量升高,即对其生长生理造成了胁迫,使其抗逆性减弱。[Purpose]To study the effects of polyethylene glycol(PEG)simulation of drought stress on the growth and physiological conditions of cassava.[Methods]Cassava NZ199 was used as the experimental material,and its root was immersed in PEG solutions with mass fraction of 0%,5%,10%,15%,and 20%for a nine-day simulated drought stress experiment.Its growth,photosynthesis and physiological indexes were measured on the 3rd,6th and 9th day,respectively.[Results]With the increase of PEG mass fraction,the growth indexes of NZ199 showed a trend of increasing and then decreasing in the same period.The net photosynthetic rate,stomatal conductance and transpiration rate showed the promotion by low mass fraction and inhibition by high mass fraction,which was the highest in 10%PEG treatment at the early stage of the treatment(≤3 d),and 5%PEG treatment at the late stage(≥6 d).The soluble protein content showed a trend of increasing and then decreasing,and the highest content was found in 10%PEG treatment for the 6th and 9th day.The proline content of 15%and 20%PEG treatments was significantly higher than other treatments.The peroxidase activity showed a tendency of increasing and then decreasing,and was highest at the 6th day of 10%PEG treatment.The catalase activity gradually increased,and was highest at the 9th day of 20%PEG treatment.The malondialdehyde content gradually increased,and was highest at the 9th day of 20%PEG treatment,indicating that the stress level was the highest.[Conclusion]At the seedling stage of NZ199,PEG simulated drought stress with appropriate mass fraction and duration can promote photosynthesis and facilitate assimilate accumulation in plants,but excessively high mass fraction will have a reverse effect on plants,showing that leaf photosynthesis decreases,and proline content,catalase activity and malondialdehyde content increase,that is,stress is caused to their growth physiology and stress resistance is weakened.

关 键 词：木薯 干旱胁迫 聚乙二醇 渗透调节物质 抗氧化酶系统 

分 类 号：S533.01[农业科学—作物学]