不同小麦品种氮、硫积累特性与子粒品质的关系

Relationship between grain quality and the accumulation of nitrogen and sulfur in different wheat cultivars

依据小麦子粒含硫量和N/S比值的差异,用聚类分析方法,将供试的12个小麦品种分为3组:高N/S比组、中N/S比组和低N/S比组。研究不同类型小麦氮硫积累特性及其与子粒品质的关系,结果表明,小麦植株的氮素积累量与硫素积累量呈极显著正相关,氮素收获指数与硫素收获指数之间无显著线性相关关系。高N/S比组品种具有较高的氮素积累量或氮素收获指数,但硫素收获指数或硫素积累量相应较低;中N/S比组品种氮素收获指数高,硫素收获指数亦高;低N/S比组品种硫素积累量和硫素收获指数均较高,但氮素收获指数较低,植株体积累的氮素和硫素在子粒中分配比例的不同是品种间子粒N/S比值差异的重要原因。不同N/S比组品种比较,子粒谷蛋白含量、谷蛋白含量与醇溶蛋白含量比值、面团形成时间和稳定时间存在显著差异,且与子粒N/S比值呈极显著二次曲线关系,适宜的N/S比有利于子粒谷蛋白的积累及子粒品质的形成。

The relationships between grain quality and the accumulation of nitrogen and sulfur in 12 wheat cuhivars were examined. The wheat cultivars were classified into three groups： high N/S ratio, medium N/S ratio and low N/S ratio. The results showed that sulfur accumulation correlated positively with nitrogen accumulation （P 〈 0. 001 ）, but no significant line correlations between nitrogen harvest index and sulfur harvest index were observed. High N/S ratio cuhivars had higher nitrogen accumulation rate but lower sulfur harvest index, or higher nitrogen harvest index but lower sulfur accumulation rate. Medium N/S ratio cultivars had higher nitrogen harvest index and higher sulfur harvest index. Low N/S ratio cultivars had lower nitrogen harvest index, higher sulfur accumulation rate and higher sulfur harvest index. The proportions of nitrogen and sulfur allocation to grain were the main reason causing for the difference of N/S ratio in grain over different cultivars. There were significant differences in the content of glutenin, the glutenin/gliadin ratio, dough development time and stability time between different groups, and all parameters had a quadric curved lines relation with N/S ratio in grain. Suitable N/S ratio in grain was propitious to the accumulation of glutenin and the grain quality.