关键词: 玉米；散粉前后；高温胁迫；产量；吐丝持续时间, 散粉持续时间； 耐热鉴定

Abstract: In order to explore the effect of pre- and post-anthesis high-temperature stress on growth,silking and anthesis characteristics and yield, 25 advanced cross combinations with separate genetic background were used as materials,42℃ was imposed through automatic intelligent heating system from 10 d before anthesis to 10 d after anthesis,with the suitable temperature as control.The results showed that after high temperature treatment,silking duration was prolonged as much as 7 days compared with the control; the anthesis duration was shorter, and anthesis-silking interval was elongated. After high temperature treatment,the SPAD values of all cross combinations decreased by 4.1%—12.9%,plant height increased by 1.1%—35.4%,the dry weight of the shoots all decreased by more than 10%,and dry root weight,ear height and stem diameter of all cross combinations were all affected,but the change trends were inconsistent. High temperature treatment before and after anthesis reduced grain yield by 1.8%—11.3%.According to the heat resistance coefficient and membership function value, the cross combinations 22 and 14 were relatively heat resistant.According to the results of principal component analysis,9 traits including duration of silking and anthesis,silking-anthesis interval,grain yield per ear,dry shoot weight and root weight, plant height, stem diameter and root-shoot ratio could be used as indicators for heat resistance screening of hybrid combinations.

Key words: Maize, Pre- and post-anthesis, High temperature stress, Yield, Silking duration, Anthesis duration, Heat tolerance identification