冬小麦种子萌发期抗旱性的基因型差异

Genotype Difference of Winter Wheat Drought Resistance at Seed Germination Stage

为准确评价冬小麦种子萌发期抗旱性的基因型差异,利用15%浓度聚乙二醇(PEG-6000)高渗溶液模拟干旱胁迫,选取22个小麦品种进行种子萌发实验,通过对根长、芽长、根干重、芽干重、发芽势等9个指标的测定,并运用相关分析、主成分分析、隶属函数等方法分析了不同小麦品种萌芽期对干旱胁迫的响应。结果表明,品种间不同指标抗旱指数的变异程度不同,其中发芽势、根长、芽长、根干重、芽干重的抗旱指数变异系数均大于100%,以发芽势变异最大,变异系数达到186.30%,而种子总干重变异最小。通过主成分分析,将9个指标转化为三个相互独立的综合指标,其累计贡献率达到94.43%。根据抗旱性综合评价值(D)进行聚类分析,将22个小麦品种分为四类,其中第一类,D≥0.5,抗旱能力较强,包括长旱58、西杂5号和陕麦139;第二类,0.4≤D<0.5,中等抗旱,包括航麦6号、晋麦47和轮选988;第三类,0.19≤D<0.4,对干旱中度敏感,包括西农223等7个品种;第四类,D<0.19,抗旱能力较弱,包括漯麦18、郑麦7698和天麦535。

In order to understand drought difference among wheat genotypes at seed germination stage,a hydroponic experiment was conducted to measured the root length,gemmule length,root dry weight,gemmule dry weight,residual seed weight total seed weight,seed germination potential and rate of 22 wheat cultivars under simulated drought stress with 15% PEG-6000.A comprehensive evaluation for wheat drought resistance was achieved through correlation analysis,principal component analysis,subordinate function analysis and cluster analysis.The results indicated that the variations of 9indexes were significantly different in their drought indexes among the cultivars.The variation coefficients of germination potential,root length,shoot length,root dry weight and shoot dry weight were higher than 100%.The germination potential had the largest variation coefficient(186.30%).The variation coefficient of seed dry weight was lowest.The nine indexes were transformed to three independent and synthesized indexes by the principal component analysis,and the accumulative contribution rate of them was achieved 94.43%.In case of the synthetic evaluation value(D),the 22 wheat cultivars were clustered into four groups.The first group had higer drought resistance with D≥0.5includingChanghan 58,Xiza 5and Shaanmai 139;The second group had relatively moderately drought resistance with 0.4≤D<0.5including Hangmai 6,Jinmai 47 and Lunxuan 988;The third group were sensitive to drought with 0.19≤D<0.4including 7cultivars;The third group were more sensitive to drought with D<0.19 including Luomai 18,Zhengmai 7698 and Tianmai 535.