关键词: 水稻, 粳稻, 小粒穗, 症状, 粒重, 分布

Abstract: 【Objective】Over the past two years, an abnormal growth phenomenon called shrunk-grain panicle has occurred in a large area in Jiangsu Province. The phenomenon was described in detail by figures and characters in this paper. 【Method】With Japonica rice Wuyujing 3 as the experimental material, characteristics of grain morphology distribution and grain weight were studied. Normal grains and Shrunk-grain Panicle were sampled from several representative areas. 【Result and Conclusion】The length, width, and weight of the normal grains were distributed as regular, continuous and single peaked. Plant growth typically had a right-leaning tendency. On the contrary, the distribution of the grain morphology and weight were irregular and nearly doubled that of the Shrunk-grain Panicle. The proportion of the cumulative distribution in the two kinds of peaks was closely related with the degree of Shrunk-grain Panicle. The paper discusses analysis of the phenomenon's symptoms, problems, and diagnosis.x

Key words: Rice, Japonica, Shrunk-grain Panicle, Symptom, Grain weight, Distribution