南方耐旱玉米种质资源筛选和鉴定指标研究

Selection of drought resistant materials and drought resistant index for maize in South China

南方7-8月份的季节性干旱严重威胁着春玉米孕穗至扬花期和秋玉米苗期的生长,影响产量。为了筛选适应南方季节性干旱气候特性的种质资源,本文针对南方的气候特性,在玉米苗期（4叶期）采用反复干旱称重控水和孕穗至扬花期采用反复干旱等量浇水的方法进行干旱处理,比较和分析了12个玉米自交系的耐旱性和与耐旱性有关的主要指标。结果表明,12个玉米自交系中,苗期和孕穗至扬花期最耐旱的自交系为“178”,苗期耐旱性最敏感的材料为“齐319”,孕穗至扬花期最敏感的是“S4080”。苗期筛选对干旱敏感的材料时,反复干旱称重控水的处理时间以7 d为宜;筛选耐旱材料时,处理时间以12 d为宜。幼苗成活率可作为耐旱筛选的评价指标,光合作用速率可作为玉米苗期耐旱材料筛选的快捷方便指标,处理前后相对电导率、脯氨酸和可溶性糖含量的变化可作为玉米苗期耐旱材料的生理筛选指标。

Drought climate （July to August） in southern China poses tremendous threat to maize production. In this paper, drought-resistance characteristics and indexes of 12 maize inbred lines were investigated by water weight control method at seedling stage, and equivalent water supply at booting to filling stage of maize. The results show that ＂178＂ is the most drought-resistant inbred line at seedling and booting to filling stages, while ＂ Qi319＂ and ＂S4084＂ are the drought-sensitive inbred lines at seedling and booting to filling stages. For drought-sensitive materials, 7 days is the longest drought duration at seedling stage, and for drought-resistant materials, 12 days is the longest duration. Seedling survival rate can be used as drought-evaluation index while photosynthetic rate and the difference between pre- and post-treatments of relative electric conductivity as well as proline and soluble sugar contents can be handy and reliable drought-evaluation index.