桑树同源多倍体品种在PEG模拟干旱胁迫下的相关生理生化指标变化  

Physiological and Biochemical Indicator Changes of Mulberry Autopolyploid Varieties Under PEG-simulated Drought Stress

作　　者：郭龙[1] 朱大鹏[1] 张敏娟[1] 苏超[1] 钱永华[1] 焦锋[1] 

机构地区：[1]西北农林科技大学蚕桑丝绸研究所,陕西杨凌712100

出　　处：《蚕业科学》2014年第5期774-780,共7页ACTA SERICOLOGICA SINICA

基　　金：西北农林科技大学基本科研业务费专项(No.ZD2012008;XNY2013-27);公益性行业(农业)专项(No.201303057)

摘　　要：为了探究桑树多倍体品种耐旱性能的生理生化机制,利用渗透调节剂PEG6000模拟干旱胁迫环境,检测分析二倍体品种新一之及其同源三倍体品种陕桑305和混倍体品种陕桑402(四倍体与二倍体混合)部分与耐旱性能有关的生理生化指标变化。不同倍数性桑品种的幼苗在干旱胁迫处理14 d后的生理生化指标出现明显差异:三倍体品种陕桑305叶片的相对含水量、超氧化物歧化酶(SOD)活性和可溶性糖含量最大,相对电导率、丙二醛(MDA)含量最小;混倍体品种陕桑402的各项指标介于二倍体品种新一之和三倍体品种陕桑305之间。依据上述指标的检测结果,评价3个桑品种的耐干旱能力依次为三倍体品种陕桑305>混倍体品种陕桑402>二倍体品种新一之,这与3个品种的桑苗在形态上表现出的对干旱的适应能力一致。推测桑树多倍体品种由于基因组加倍后的基因表达模式发生改变,使一些与抗逆能力相关的酶类活性和代谢物的含量提高,从而使耐干旱能力增强。In order to explore drought-tolerant physiological and biochemical mechanisms of mulberry polyploid varieties,PEG6000 was used as osmosis regulator to simulate environmental drought stress,and changes of some drought resistance related physiological and biochemical indexes in diploid mulberry variety New-Ichinose and its autotriploid variety Shansang 305 and mixoploid（ i. e. tetraploid with diploid） variety Shansang 402 were analyzed. The results showed that physiological and biochemical indexes of mulberry saplings with different ploidy were obviously different at 14 d after drought stress. Leaves of triploid variety Shansang 305 had the highest relative water content,superoxide dismutase（ SOD） activity and soluble sugar content,but the lowest relative conductivity and malondialdehyde（ MDA） content. All indicators of mixoploid variety Shansang 402 were between those of diploid variety New-Ichinose and triploid variety Shansang 305. Based on these results,drought resistance of these three mulberry varieties was in the order of triploid variety Shansang 305 〉mixoploid variety Shansang 402 〉diploid variety New-Ichinose,which was consistent with their adaptability to drought stress shown on their morphology. It is speculated that mulberry polyploid varieties resulted from genome doubling possess different gene expression patterns,have improved activity of resistance re-lated enzymes and higher productivity of certain metabolites,all of which lead to the increase of drought resistance.

关 键 词：桑树多倍体 干旱胁迫 相对含水量 超氧化物歧化酶 可溶性糖 相对电导率 丙二醛 

分 类 号：S888.2[农业科学—特种经济动物饲养]