玉米苗期不同供水条件下水分利用效率鉴定指标研究

试验在防雨棚中盆栽条件下进行。供试玉米杂交种5个,苗期设置正常供水、轻度干旱胁迫和中度干旱胁迫3种处理,拔节期均复水到正常水平。分别在拔节期、吐丝期和成熟期对相关形态及生理指标进行测定,并与水分利用效率(water use efficiency,WUE)进行多元逐步回归分析。结果表明:在吐丝期,正常供水和中度干旱时散粉至抽丝间隔(anthesis-silking interval,ASI)短的品种WUE高;在成熟期,正常供水时粒叶比高、茎较粗和轻度干旱时粒深的品种WUE高;在正常供水时,拔节期植株矮小、叶片失水率小、成熟期收获指数(harvest index,HI)较高和穗位比较大的品种在轻度干旱胁迫下具有较高WUE;在正常供水时,出籽率较高、行粒数较少的品种在中度干旱胁迫下具有较高WUE。

Studies on Identify Indices of Water Use Efficiency of Maize During Seedling Stage with Different Water Supply

Pot experiment was carried out with 5 maize hybrids under three levels of water supply treatment(light drought stress, modest drought stress and CK) during seedling stage in a rain shelter. And normal water treatment was recovered in the joining stage. The relative indices were measured in the joining stage, silking stage and harvest stage respectively. Multiple regression analysis was made between water use efficiency(WUE) and all measured indices. The result showed that the varieties with short anthesis-silking interval(ASI) had high WUE in silking stage under both normal water condition and modest water drought stress level. In harvest stage, the varieties with high grain-leaf ratio and thick stem had high WUE under normal water condition, the varieties with deep gain deepness had high WUE under light water drought stress level. The varieties with slim plant and low water losing rate in the joining stage, high harvest index(HI) and high spike/plant-highness rate in the harvest stage under normal water condition have high WUE under light water drought stress level. The varieties with high kernel percentage and little kernel number per row in the harvest stage under normal water condition have high WUE under modest water drought stress level.