水稻籽粒蛋白质含量的空间分布特征

为解析2种穗型水稻籽粒蛋白质含量的空间分布特征。以弯曲穗型‘两优培九’和直立穗型‘武香粳14号’为材料,研究了在2个施氮水平下,籽粒蛋白质含量在穗上不同部位和不同粒位间的差异及其分布特征。结果表明:穗内各籽粒在不同蛋白质含量区间的频数变化趋势呈正态分布;在稻穗的同一部位,2个供试品种一次枝梗上的籽粒蛋白质含量高于二次枝梗;一次枝梗上的籽粒蛋白质含量以第2粒位籽粒较低,第1粒位的籽粒较高;二次枝梗上第1粒位籽粒的蛋白质含量较高。蛋白质含量在穗上不同部位及一、二次枝梗上的分布因品种和施氮量的不同而异,施氮量在110~220 kg/hm2范围内,增施氮肥可以减少穗内粒间的籽粒蛋白质含量差异。

Spatial Distribution of Protein Content in Rice Grain

Protein content (PC) of the grain is one of the most important quality indexes of rice. Grain development on rice panicle is asynchronous. However, little is known what difference in the PC characters among the grains at different position within a rice panicle. The primary objective of this study is to elucidate the spatial distribution of protein content in rice grain with erect panicle and curved panicle. This study investigated the distribution of the percentages of PC for different grains on a panicle. The experiment with two cultivars and two nitrogen rates was conducted in Nanjing. All primary branches on a panicle were evenly divided into three parts of the upper, middle and basal. The grains were numbered as 1 to 6 on a primary branch and 1 to 3 on a secondary branch from the top to base. Results indicated that frequency of grains at different PC range in a panicle was normal distribution. The grains PC on a primary branch were greater than those on a secondary branch at the same part of a panicle; on a primary branch, the grain 2 had the least PC, and the grain 1 had the greatest; on a secondary branch, the grain 1 had the greatest PC. The distribution of PC at different parts within a rice panicle or on a primary branch or on a secondary branch varied with the cultivar and the amount of nitrogen applied. Application of nitrogen fertilizer could decrease the difference of grains PC in different position within rice panicle when the amount of nitrogen was between 110 kg/hm² and 220 kg/hm².