施氮对大穗型两系杂交水稻弱势粒碳氮代谢的影响

Effects of Nitrogen Application on Metabolism of Carbohydrate and Nitrogen in the Inferior Grains of Hybrid Rice with Large Panicle

以2个大穗型两系杂交水稻品种培杂67和培杂88为材料,研究3种不同施氮水平(LN.90 kg/hm2,MN.180 kg/hm2,HN.270 kg/hm2)对大穗型两系杂交水稻弱势粒碳氮代谢的影响。结果表明,与正常施氮相比,过量施氮提高了子粒谷氨酰胺合成酶活性,促进了可溶性蛋白质的生成,但降低了弱势粒中蔗糖的含量和蔗糖合成酶的活性,减少了淀粉积累量,最终降低了弱势粒粒重;施氮量过少则降低了弱势粒蔗糖含量、蔗糖合成酶和谷氨酰胺合成酶的活性,从而导致弱势粒中的淀粉和可溶性蛋白质的积累量减少,弱势粒的充实度降低;施氮量对强势粒充实度影响不大。

Studies were conducted to investigale the effects of 3 different levels of nitrogen application（LN.90 kg / hm2;MN.180 kg / hm2;HN.270 kg / hm2） on metabolism of carbohydrate and nitrogen in the inferior grain of 2 two-line hybrid rice cultivars with large panicle,Peiza 67 and Peiza 88.The results showed that compared with the control（MN）,higher nitrogen rates improved activity of glutamine synthetase and soluble-protein content,but decreased sucrose content,activity of sucrose synthase and starch accumulating amount in inferior grains,thus causing the inferior grain weight decreased.Lower nitrogen rates decreased sucrose content,activity of sucrose synthase and glutamine synthetase in inferior grains,thus causing the starch and soluble-protein accumulating amount reduced,which resulted in reducing the grain plumpness.Nitrogen application rate had little effect on the superior grains.