Genotypic differences in response of physiological characteristics and grain yield of maize inbred lines to drought stress at flowering stage

Flowering stage is a critical period which influences the production of maize,and identifying traits related to drought tolerance of maize at flowering stage is of significance for drought-resistant breeding and germplasm improvement.In this study,we analyzed differences between drought-tolerant inbred lines(Langhuang and Chang7-2)and a drought-sensitive inbred line(TS141)of maize at flowering stage.The results are as follows.Drought inhibited maize growth,with leaf relative water content decreased whereas senesced leaf rate,relative conductivity rate,proline and soluble sugar content,and antioxidative activities increased.Compared with drought-sensitive line TS141,drought-tolerant lines Langhuang and Chang7-2 was slightly inhibited,with larger contents of leaf relative water,proline and soluble sugar,higher activities of antioxidative enzymes like SOD and POD,and lower relative electric conductivity.After drought stress,anthesis-silking-interval(ASI)of three inbred lines was prolonged,and tassel branch level and yield was reduced.Langhuang and Chang7-2 had shorter ASI extension and less reduction in tassel branch level and yield,especially weight per ear and kernel number per ear.