中文摘要：

水稻粒宽是影响籽粒粒形的重要因素之一,也是一个与水稻产量和稻米品质密切相关的重要性状。在基因GS5序列分析的基础上,对该基因第2外显子的ACC/CTA和第9外显子A/C的两个变异位点分别开发了功能标记,并将其用于294份水稻微核心种质和2007-2013年江苏省审定的65份粳稻品种的基因型鉴定。研究结果表明,这两个变异位点的等位变异在水稻籽粒的粒长、粒宽和长宽比性状上存在显著或极显著的差异;其在水稻微核心种质中组成的4种单倍型在水稻籼亚种的粒宽、粒厚和长宽比性状上存在极显著的差异,在粳亚种的粒宽和长宽比性状上存在极显著的差异;而江苏省审定的粳稻品种中仅发现Hap1和Hap2两种单倍型,其分别有64个和1个代表性品种。这些研究结果为水稻产量和稻米品质育种中充分利用GS5的优异等位基因或单倍型奠定了基础。

英文摘要：

As a major component of rice grain shape,the grain width is an important trait which is correlated with the rice yield and quality.Based on the alignment of gene GS5 genomic DNA sequence,two functional markers were developed based on two missense polymorphisms（ACC/CTA in the exon2,A/C in the exon9,respectively）.Subsequently,the markers were used to identify the genotypes of gene GS5 in the 294 accessions of a rice mini-core collection and 65 japonica varieties released in Jiangsu Province from 2007 to 2013.We found that the allelic variations at the two target loci had significant or extremely significant differences in the grain shape traits（grain length,grain width and ratio of length to width）.Based on the two variation sites of gene GS5,four haplotypes（combinations）were found in the rice mini-core collection,and had extremely significant effect on grain width,grain thickness and ratio of length to width in the indica group,and on grain width and ratio of length to width in the japonica group,respectively.While in japonica varieties released by Jiangsu,only two haplotypes,Hap1（represented by 64varieties）and Hap2（represented by one variety）were found.The results will lay a foundation for the application of the useful allelic variations or haplotypes of gene GS5 to the rice yield and quality breeding program.