氮肥对粳稻籽粒腹白和心白发生及生化组成的影响

为探讨不同类型垩白水稻对氮肥的响应差异,以武育粳3号的高腹白突变体(WBRK)和高心白突变体(WCRK)为材料,设置不施氮肥(对照)和两个不同的基肥与穗肥比例处理(N5-5和N10-0)共3个处理,分析施氮对腹白米和心白米的发生及籽粒生化组分的影响。结果表明,施用氮肥显著增加了腹白米率和心白米率,且腹白较心白更易受氮肥影响。施氮对WBRK籽粒总淀粉、直链淀粉和支链淀粉含量无显著影响,显著增加了WCRK籽粒淀粉组分的含量,改善了WBRK和WCRK的碾磨品质。与对照相比,N5-5处理显著增加了WBRK籽粒蛋白质及其组分中球蛋白、醇溶蛋白和谷蛋白含量以及WCRK籽粒蛋白质含量。N10-0处理显著降低了WBRK和WCRK籽粒中的蛋白质和谷蛋白含量。N5-5处理下,WBRK和WCRK籽粒中大多数氨基酸含量有所增加,但组氨酸和精氨酸含量有所降低,WCRK表现得更明显。研究表明,氮素对不同类型垩白水稻品种腹白和心白发生及籽粒贮藏物质积累的影响存在差异,显示出生产中采用不同调优栽培措施的必要性。

Effects of Nitrogen Fertilizer Application on the Formation of White-belly and White-core as Well as Biochemical Composition of japonica Rice Grains

The white-belly and white-core mutants (WBRK and WCRK) from Wuyujing 3 were used to clarify the effects of nitrogen application levels (zero nitrogen application,CK; the ratio of basal N fertilizer to topdressing N fertrlizer for panicle initiation 1:1,N5-5; N fertilizer as basal fertilizer N10-0) on the occurrence of white-belly and white-core grains as well as grain chemical components. The results showed that Nitrogen application significantly increased the percentages of white-belly and white-core grains and the latter was more susceptible to nitrogen application. Averaged across nitrogen treatments, WBRK produced grains with similar chemical composition in comparison with those of control. By contrast, WCRK had higher total starch, amylose and amylopectin contents. Also, nitrogen application improved rice milling quality. Compared to CK, rice grains from WBRK showed significantly elevated contents of storage proteins except for albumin as nitrogen topdressing rate increased, while rice grains from WCRK contained significantly higher levels of protein with no significant changes in protein compositions. Nitrogen topdressing increased the contents of the majority of the 17 amino acids, but decreased histidine and arginine contents especially for WCRK. These findings suggested that nitrogen application exerted a significantly different influence on the occurrence of white-belly and white-core kernels and the accumulation of starch and protein during grain filling, indicating the necessity of various formulated strategies to eliminate white-belly and white-core grains.