PEG胁迫下糜子苗期抗旱指标鉴选研究

摘要

The study analyzed the drought-resistance indexes of broomcorn millet at seedling stage to provide theoretical basis for identifying drought resistance and screening broomcorn millet species.With simulate water stress by 0.25 g/mL PEG6000,the relationships of morphological indexes,physiological and biochemical indexes with drought resistance of broomcorn millet at seedling stage for 10 broomcorn millet cultivars were investigated.The results showed that the peroxidase（POD） activity,malondialdehyde（MDA） content,soluble protein（SP） content and superoxide anion（O-·2） were markedly increased,while plant height（PH）,leaf length（LL）,chlorophyll（Chl） content,relative water content（RWC） and superoxide dismutase（SOD） activity were significantly decreased.The significance for correlation of survival rate（SR） with nine test indexes was decreased in the order of SOD activity,Chl content,MDA content,POD activity,O-·2,RWC,LL,PH and SP content;Through factor analysis,the ten test indexes were divided into two common factors,among which,the indexes of Chl content,active oxygen metabolism,membrane stability and SR played important roles in the first factor,while growing development,RWC and osmotic adjusting materials dominated in the second factor.The grey correlative degree of SR with other indexes was in the rank of SOD activity,Chl content,POD activity,PH,RWC,LL,SP,O-·2 and MDA content.Therefore,the activities of SOD and POD,and Chl content can be used as an effective indicators for drought resistance identification,while LL,PH,SP,MDA and O-·2 can be used for reference indicators at seedling stage in broomcorn millet.%研究糜子苗期抗旱指标,为糜子品种抗旱性鉴定和品种筛选提供理论依据。选用10个不同基因型糜子为材料,通过0.25g/mL聚乙二醇6000（PEG6000）模拟干旱的方法,研究了糜子苗期部分形态指标、生理生化指标与抗旱性的关系。结果表明：水分胁迫下糜子叶片过氧化物酶（POD）活性、丙二醛（MDA）含量、可溶性蛋白（SP）含量以及超氧阴离子自由基（O2-.）明显提高,而株高（PH）、叶长（LL）、叶绿素（Chl）含量、叶片相对含水量（RWC）和超氧化物歧化酶（SOD）活性显著降低。存活率（SR）与以上9个形态、生理生化指标的相关性大小依次为SOD活性〉Chl含量〉MDA含量〉POD活性〉O2-.〉RWC〉LL〉PH〉SP含量;通过因子分析将10个抗旱性指标用2个公共因子表示,累积贡献率达到92.648%,因子1反映叶绿素含量、活性氧代谢、质膜稳定性及SR对抗旱性起支配作用,因子2中反映糜子生长发育、叶片相对含水量及渗透调节物质对抗旱性起支配作用;灰色关联度分析表明,各抗旱性形态、生理生化指标与SR关联密切程度依次为SOD活性〉Chl含量〉POD活性〉PH〉RWC〉LL〉SP〉O2-.〉MDA含量。因此,在糜子苗期鉴定中,糜子叶片内抗氧化酶系统指标SOD、POD活性以及Chl含量可作为抗旱性鉴定的有效指标,而LL、PH、SP、MDA含量和O2-.含量可作为参考指标。