水分胁迫对耐旱性不同小麦小花化发育和氮磷及激素含量的影响

土壤分水分亏缺导致小麦幼穗内氮、磷、异戊烯基腺嘌呤（ｉＰＡｓ）含量降低，脱落酸（ＡＢＡ）含量升高，影响小花的发育，结实粒数减少。在水分充足的条件下，耐旱性不同的品种穗中氮、氮、ｉＰＡｓ含量和ＡＢＡ含量无显著差异；在水分胁迫条件下，旱地品种幼穗中氮，磷、ｉＰＡｓ含量降低的幅度和ＡＢＡ含量升高的幅度低于水浇地品种，这是耐旱品种在土壤水分亏缺时，较水浇地品种小花发育好、成花率和结实率高，穗粒数稳定的生理

Effect of water stress on floret differentiation and the content of nitrogen,phosphorus and plant hormone in different drought enduring wheat

Soil water deficit resulted in the content of nitrogen,phosphorus,and iPAs declined while of ABA improves,and had effects on floret differentiation and development.As a result,the fructiferous grains decreased.Under adequate water condition,there was no remarkable difference of the content of nitrigen,phosphorus,iPAs,and ABA in spike among different drought enduring wheat cultivars.Under water stress condition,both the declined range of the content of nitrogen,phosphorus,and iPAs and the improved range of the content of ABA in spike of nonirrigated farmland cultivars were significant lower than those of irrigated farmland cultivars.This is the physiological reason why,compared with irrigated farmland cultivars,the nonirrigated farmland cultivar had more floret primordia,higher percentage of generated floret and seed setting,as well as more stable number of grains per spike under soil water deficit condition.