谷子种质资源萌发期抗旱性综合评价及抗旱指标筛选

为探究适宜的谷子抗旱性评价方法，以35个谷子品种为材料，设置0.03 mol/L PEG-6000溶液模拟干旱胁迫以及正常浇水2个处理，采用频次分析和相关性分析比较了9个与谷子萌发期抗旱性相关的指标，依据隶属函数求出最适宜的综合抗旱性鉴定标准，并以此为依据对所选品种进行聚类并划分抗旱等级。结果表明:在干旱胁迫下，受试品种谷子的发芽势、发芽率、萌发指数、根干重、根鲜重、芽干重、芽鲜重、芽长和根长均受到不同程度的抑制，干旱对发芽势的影响最大；除萌发系数以外发芽势与其余各指标均呈显著或极显著相关，通过因子分析将9个单项性状指标转化为4个因子，累计贡献率达86.74%。通过隶属函数结合聚类分析将35个谷子品种的抗旱性划分为4级，其中强抗旱型品种7个、中度抗旱型品种15个、干旱敏感型品种9个和干旱极敏感型品种4个。通过回归分析建立了可准确评估谷子萌发期抗旱性的回归方程y=-0.187+0.554x_RBDW+0.550x_RRL+0.264x_RRFW，筛选出相对根鲜重、相对芽干重和相对根长作为谷子萌发期抗旱性鉴定的重要指标。干旱胁迫下，可通过测定这3个指标对不同品种谷子萌发期的耐旱性进行快速准确的鉴定及评价。

Comprehensive evaluation of drought resistance of foxtail millet germplasm resources during germination period and drought resistance index screening

In order to identify suitable drought resistance evaluation methods of foxtail millet, a total of 35 foxtail millet cultivars were used in this study. Experiments were conducted under both normal irrigation and 0. 03 mol/L PEG-6000 solution drought stress to simulate drought resistance. Frequency analysis and correlation analysis were conducted to compare the correlation between the selected nine indicators and the drought resistance during foxtail millet germination. Factor analysis combined with step wise regression analysis was used to screen the effective evaluation indicators for drought resistance of germination. The most suitable comprehensive drought resistance identification standard was obtained through the membership function, and based on this, the selected cultivars were clustered and the drought resistance levels were classified. The results showed that: The germination potential, germination rate, germination index, root fresh and dry weight, bud fresh and dry weight, bud and root length of the 35 cultivars were inhibited, among which the germination potential was affected most by the drought stress. Except the germination coefficient, the germination potential was extremely significant or significantly correlated with other indicators. Through factor analysis, the nine individual traits were transformed into four factors with a cumulative contribution rate of 86. 74%. The drought resistance of 35 foxtail millet cultivars was divided into four levels, including 7 highly resistant, 15 moderately resistant, 9 susceptible, and 4 extremely intolerant foxtail millet cultivars through membership function combined with cluster analysis. Meanwhile, a regression equation, y=-0. 187+0. 554x_RBDW+0. 550x_RRL+0. 264x_RRFW, was established to estimate the tolerance of foxtail millet cultivars to drought stress. The relative root fresh weight, relative bud dry weight and relative root length were identified as important indicators to assess the resistance of foxtail millet germination. In conclusion, under drought stress, the drought tolerance of different varieties of foxtail millet at germination stage could be identified and evaluated quickly and accurately by measuring the three indicators.