开花期干旱胁迫对不同基因型玉米生理特性和产量的影响

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

以耐旱性不同的3份玉米自交系为材料,在花期进行干旱胁迫处理,研究了耐旱系廊黄和昌7-2与旱敏感系TS141的花期耐旱性差异。结果表明,花期干旱胁迫后,3份玉米自交系的生长受到抑制,地上部和地下部鲜重以及株高下降,枯叶率升高,相对含水量下降,相对电导率升高,渗透调节剂脯氨酸、可溶性糖含量、保护酶SOD和POD活性增加。但是各个指标在不同自交系内变化的幅度不同。与旱敏感系TS141相比,耐旱系廊黄和昌7-2的生长受抑制程度较小;叶片相对含水量下降、相对电导率升高幅度较小;脯氨酸和可溶性糖含量、保护酶SOD和POD活性升高的幅度较大。干旱胁迫后,3份玉米自交系的开花时间间隔(ASI)延长,雄穗一级分枝数减少,产量降低。与旱敏感系TS141相比,耐旱系廊黄和昌7-2的ASI延长时间较短,雄穗一级分枝数减少的幅度较小,产量下降幅度较小,特别是单穗重和穗粒数表现更为明显。

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 improve-ment .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 solu-ble 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 ,espe-cially weight per ear and kernel number per ear .