花铃期干旱胁迫对陆地棉农艺性状的影响及其抗旱等级划分

为了探索花铃期干旱胁迫对不同棉花品种重要农艺性状的影响，并对品种进行等级划分，以前期鉴定的30份陆地棉品种进行试验，测定不同品种干旱胁迫组和对照组的农艺性状和品质指标等。通过含水量的差异性分析、农艺性状相关性分析、抗旱系数分析、3种综合评价值(D、CDC、WDC)相关性分析，证明3种评价值的评价结果一致。通过各性状与D值和WDC值的关联度分析，明确伸长率、单株产量、比强度和整齐度4个指标可作为品种抗旱性鉴定的重要指标。以D值进行聚类分析，对30份品种进行了抗旱等级分类，共分为4大类。第I大类，共有DG219、DG168、DG186等3份材料，属于强抗旱类别；第Ⅱ大类，共有DG270、DG228等12份材料，属于抗旱类别；第Ⅲ大类，仅有1份材料(DG248),属于较敏感类别；第Ⅳ大类，共有DG43、DG42等14份材料，属于敏旱类别。研究结果为品种的鉴定和利用提供了参考依据。

Effects of drought stress on agronomic traits of upland cotton at flowering boll stage and its classification of drought resistance

Through the study the effects of drought stress on the root traits and the variety resources during the flowering and boll stage were divided into grades. 30 upland cotton varieties identified in the early stage were used to determine the agronomic traits and quality indexes of different varieties under two treatments: drought stress group and control group. Different analysis in water content, correlation analysis of agronomic traits, drought resistance coefficient, and correlation analysis of three comprehensive evaluation values (D, CDC, WDC) proved that the evaluation results of the three evaluation values were consistent. By analyzing the correlation between various traits and D and WDC values, it was clear that the four indexes of elongation, yield per plant, specific strength,and uniformity were important indicators for the identification of drought resistance of varieties. Based on the cluster analysis of D value, 30 varieties were classified into four categories. In the first category, there were 3 materials including DG219, DG168 and DG186, which belong to the category of strong drought resistance. In category II, there were 12 materials such as DG270 and DG228, which belong to the drought\|resistant category. In category III, only DG248 material was used, which was a more sensitive category. In category IV, there were 14 materials such as DG43 and DG42, which belong to the category of sensitive drought. Thus, it provides a reference basis for the identification and utilization of varieties.