三个小麦新品种萌发期和幼苗期抗旱性的综合评价

摘要

In order to identify the drought resistance of three new wheat cultivars Xinong 538,Xinong 556 and Xinong 558,three wheat cultivars Jinmai 47,Xiaoyan 22 and Xinong 979 with different drought resistance and large area of promotion were taken as control.The experiment was conducted under four PEG-6000 treatments (5％,10％,15％ and 20％) for six wheat cultivars.12 indices (germination rate,germination potential,coleoptile length,SOD,CAT,etc.) was investigated during germination and seedling stage.The comprehensive evaluation for wheat drought resistance was conducted by correlation analysis,principal component analysis and subordinate function analysis.The results indicated that there existed different degree of correlation among these indices and these indices had different effects on the drought resistance of the varieties.By principal component analysis,12 indices was transformed to three (under 15％ and 20％ PEG-6000) or four (under 5 ％ and 10％ PEG-6000) independent and synthesized indices,and the accumulative contribution rate were 92.61％ ％,92.96 ％,88.74 ％ and 93.12 ％ for stress treatments of 5 ％,10％,15 ％ and 20％,respectively.According to the synthetic evaluation value (D),six wheat cultivars were divided into three groups,in which "Xinong 538" and "Jinmai 47" belonged to the high drought resistance group,"Xinong 558" and "Xiaoyan 22" belonged to the medium drought resistance group,and "Xinong 556" and "Xinong 979" belonged to the low drought resistance group.%为了鉴定西农538、西农556和西农558三个小麦新品种的抗旱特性,以抗旱性不同的三个生产上大面积推广的小麦品种晋麦47、小偃22和西农979为对照,通过在不同梯度的渗透胁迫(5％,10％,15％,20％ PEG-6000)处理下,测定这6个品种在萌发期和幼苗期的发芽率、发芽势、胚芽鞘长、超氧化物歧化酶活性(SOD)、过氧化物酶(CAT)等指标,运用相关分析、主成分分析、模拟隶属函数等方法对这6个品种的抗旱性进行综合评价.结果表明:(1)在不同梯度的渗透胁迫处理下,各单项指标对不同品种抗旱性的影响不同,各指标间存在不同程度的相关性.(2)通过主成分分析,5％和10％PEG胁迫下将12个单项指标转化为4个相互独立的综合指标,15％和20％PEG胁迫下将12个单项指标转化为3个相互独立的综合指标,4种胁迫梯度下其累计贡献率依次达到了92.61％、92.96％ 、88.74％和93.12％.(3)通过抗旱性综合评价值(D值),将这6个小麦品种分为三类:西农538与对照品种晋麦47为强抗旱型;西农558与对照品种小偃22为中等抗旱型;西农556与对照品种西农979为弱抗旱型.