Fine Mapping and Cloning of the Grain Number Per-Panicle Gene (Gnp4) on Chromosome 4 in Rice (Oryza sativa L.)

作     者：ZHANG Zhan-ying LI Jin-jie YAO Guo-xin ZHANG Hong-liang DOU Hui-jing SHI Hong-li SUN Xing-ming LI Zi-chao 

作者机构：Key Laboratory of Crop Heterosis and Utilization Ministry of Agriculture/Beijing Key Laboratory of Crop Genetic Improvement ChinaAgricultural University Beijing 100193 P.R.China 

出 版 物：《Agricultural Sciences in China》 (中国农业科学（英文版）)

年 卷 期：2011年第10卷第12期

页      面：1825-1833页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 09[农学] 071007[理学-遗传学] 0901[农学-作物学] 

基　　金：funded by the Project of the 973 Program(2010CB125904) the 948 Program (2011-G2B) the National Natural Science Foundation of China(31171521) the National Key Technology R&D Program of China (2009BADA2B01) 

主　　题：rice gnp4 laxl-1 grain number per-panicle methylation 

摘      要：Grain number per-panicle is one of the most important components for rice yield. Spikelets on the primary and secondary branches determine the grain number per-panicle in rice. In this study, we identified a natural mutant, gnp4, lack of lateral spikelet on the secondary branches in the field condition. In addition, the Gnp4 and Lax1-1 double mutant showed dramatically reduced secondary branches and spikelets in panicle at reproductive stage, and tillers at vegetative stage. By map-based cloning approach, and using four F2 segregating populations, the Gnp4 gene was finally mapped to a 10.7-kb region on the long arm of chromosome 4 in rice. In this region, only one gene was predicted, and genomic DNA sequencing of the 10.7-kb region showed no nucleotide differences between the mutant and wild type. Interestingly, we found that the methylation level of several cytosines in the promoter CpG islands region of the predicted gene in gnp4 were different from the wild type. Thus, we propose that the DNA methylation changes at these sites may induce to decrease expression level of Gnp4, consequently, resulting in phenotypic variation.