为了筛选抗旱玉米品种，采用20%PEG-6000模拟中度干旱胁迫对41份玉米品种的萌发期进行了抗旱性评价，通过加权隶属函数法计算D值对供试材料的抗旱性进行综合评价，并通过UPGMA聚类划分抗旱等级。本试验测定了供试材料的发芽率、发芽势、胚芽鞘长、主胚根长、胚根数和干物质重6个性状，结果表明处理比对照均值分别下降了50.8%、65.6%、81.4%、57.9%、42.1%和70.0%，不同品种间差异显著。PEG-6000胁迫处理促进了部分材料根部的生长，增加了根的数量，这部分材料可能是萌发期抗旱性较强的品种。隶属函数法计算综合评价值（D值）表明，其与发芽率、胚芽鞘长等各指标抗旱系数的隶属函数值均呈极显著正相关，筛选出金海5号、粟玉6号、京农科728、美豫5号、金海1483、极峰30、荷玉157、美豫268、NK718、先玉335、金海z-2、登海618、粟玉15等13个抗旱品种。UPGMA聚类分析将试验材料在遗传距离为6.91处分为2大类。进一步可分为高度抗旱、中度抗旱、抗旱、敏感、高度敏感等5个亚群，筛选出的玉米萌发期较强抗旱品种为：粟玉6号、京农科728、金海5号、登海618、豫禾988、先玉335、美豫5号、荷玉157、金海1483、极峰30、NK718、美豫268、粟玉15。两种方法筛选出的玉米萌发期抗旱品种高度吻合。
英文摘要:
To sceen drought-resistant maize varieties , the drought resistance of 41 Maize Germplasms was evaluated by 20% PEG-6000 simulating moderate drought stress. Then the weighting membership function and D value were used to evaluate the drought resistance, and the drought resistance grade was divided by UPGMA cluster.In this experiment the germination rate, germination potential, coleoptile length, main radicle length, radicle number and dry matter weight of the tested materials were measured ,and the results showed that the mean values of the treatment group were 50.8%, 65.6%, 81.4%, 57.9%, 42.1% and 70.0% lower than those of the control group, respectively and the differences between different varieties were significant. Howerver, we found that the 20% PEG-6000 simulation stress promoted the main radicle growth of some varieties, which suggests that these material may be strong drought resistant varieties at germination stage. Moreover, D value calculated by the weighting membership function method showed that it had significantly positive correlation with drought resistance indices, such as germination rate and coleoptile length.Based on this result, 13 drought-resistance germplasms Jinhai 5, Suyu 6, Jingnongke 728, Meiyu 5, Jinhai 1483, Jifeng 30, Heyu 157, Meiyu 268, NK718, Xianyu 335, Jinhai Z-2, Denghai 618 and Suyu 15 were screened out.Through UPGMA clustering analysis, the materials were divided into two major categories at the genetic distance of 6.91. Furthermore, it could be divided into 5 subgroups: high drought resistance, moderate drought resistance, drought resistance, sensitivity and high sensitivity. Therein, the screened maize varieties with strong drought resistance at Germination Stage were Suyu 6, Jingnongke 728, Jinhai 5, Denghai 618, Yuhe 988, Xianyu 335, Meiyu 5, Heyu 157, Jinhai 1483, Jifeng 30, NK718, Meiyu 268 and Suyu 15.Noticeably,The two methods screening drought-resistent maize varieties at germination stage were highly consistent.
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