西兰花在PEG模拟干旱胁迫条件下的生理响应分析  

Study on Physiological Responses of Broccoli under PEG Simulated Drought Stress

作　　者：邵勤 陈娜 李晓鹏 袁九香 SHAO Qin;CHEN Na;LI Xiao-peng;YUAN Jiu-xiang(College of Life Science and Resources and Environment,Yichun University,Yichun 336000,China;Nanchang Rural Social Affairs Service Center,Nanchang 330000,China)

机构地区：[1]宜春学院生命科学与资源环境学院,江西宜春336000 [2]南昌市农村社会事务服务中心,江西南昌330000

出　　处：《江西农业学报》2023年第8期47-54,共8页Acta Agriculturae Jiangxi

基　　金：江西省蔬菜产业重大技术协同推广计划项目[JXXT-2022(SC)];江西省重点研发计划项目(20202BBFL63002)。

摘　　要：以西兰花“青锦”为研究对象,分别采用5%、10%、15%、20%PEG干旱胁迫处理西兰花幼苗,并检测和分析了PEG模拟干旱胁迫对西兰花生理生化特性的影响。结果表明:不同浓度PEG胁迫后,对西兰花幼苗叶片相对含水量、脯氨酸、膜透性、丙二醛含量有显著的影响,随着胁迫浓度的增加和胁迫时间的延长,其相对含水量与对照相比有不同程度的下降,脯氨酸含量、丙二醛含量和膜透性则呈上升趋势。低浓度PEG胁迫下,西兰花幼苗叶片可溶性糖含量与对照差异不显著,随着PEG浓度的增加,胁迫3 d时的可溶性糖含量急剧上升,并在胁迫7 d时开始下降。叶片可溶性蛋白质含量则在胁迫5 d时下降至最低值(0.91 mg/g),在胁迫7 d时则有所提升,总体呈现先降后升趋势;高浓度PEG胁迫,对SOD、POD、CAT、APX酶活性的影响比低浓度时大,且随着胁迫时间的延长,4种酶活性均呈现先上增加后下降趋势。相关性分析表明:RWC与SP呈极显著正相关,与Pro、REC、SS、MDA呈极显著负相关。主成分分析表明,提取特征值>1的2个主成分,其方差贡献率分别为56.517%和34.851%,累计方差贡献率达到91.368%。由此可知,模拟干旱胁迫下,不同浓度PEG对西兰花幼苗生理特性的影响排名依次为10%PEG>20%PEG>15%PEG>5%PEG。综上,西兰花“青锦”幼苗能够抵抗中等程度的干旱胁迫(10%PEG),具有一定的耐旱性。The broccoli“Qingjin”was taken as the research object,and broccoli seedlings were treated with different concentrations of PEG(5%,10%,15%,20%)under osmotic stress.The effects of PEG simulated drought stress on physiological and biochemical characteristics were detected and analyzed.The result showed that different concentrations of PEG stress had a significant effect on broccoli seedling leaf relative water content,proline,membrane permeability,malondialdehyde content.With the increase of stress concentration and stress time,the relative water content decreased to different degrees compared with the control,while the content of proline,malondialdehyde and membrane permeability increased.Under low concentration PEG stress,the soluble sugar content of broccoli seedling leaves was not significantly different from that of the control.With the increase of PEG concentration,the soluble sugar content increased sharply at 3 d and began to decrease at 7 d.The soluble protein content of leaves decreased to the lowest value(0.91 mg/g)at the 5th day,and increased at the 7th day,showing a general trend of first decreasing and then increasing.The effects of high PEG concentration on SOD,POD,CAT and APX were greater than those of low PEG concentration,and the activities of the four enzymes increased firstly and then decreased with the extension of stress time.The correlation analysis showed that RWC was significantly positively correlated with SP,but significantly negatively correlated with Pro,REC,SS and MDA.Principal component analysis showed that two principal components with future values>1 were extracted,whose variance contribution rates were 56.517%and 34.851%,respectively,and the cumulative variance contribution rate reached 91.368%.Thus,the effect of different concentrations of PEG on physiological characteristics of broccoli seedlings under simulated drought stress was in the order of 10%PEG>20%PEG>15%PEG>5%PEG.In conclusion,broccoli“Qing jin”seedlings could resist moderate PEG drought stress(10%),and had a cer

关 键 词：西兰花 PEG 脯氨酸 保护酶 耐旱性 

分 类 号：S435.111.42[农业科学—农业昆虫与害虫防治]