Awnness is a key trait in rice domestication, yet no studies have been conducted on fine mapping or association mapping of the rice awn gene. In this study, we investigated the awnness and genotype of a core collection of 303 cultivated rice varieties and a BC5F2 segregating population of 200 individuals. Combining association and linkage analyses, we mapped the awnness related genes to chromosome 4. Primary association analysis using 24 SSR markers revealed five loci significantly associated with awnness on chromosome 4. The associated markers cover previously identified regions. Fine association mapping was conducted using another 29 markers within a 4-Mb region, covering the associated marker in34, which is close to the awn gene Awn4.1. Seven associated markers were revealed, distributed over an 870-kb region. Combining the fine association mapping and linkage analysis of awnness in the 200 BC5F2 segregating population, we finally identified a 330-kb region as the candidate region for Awn4.1. The results indicate that combining association mapping and linkage mapping provides an efficient and precise approach to both genome-wide mapping and fine mapping of rice genes.
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1.Key Laboratory of Crop Genomics and Genetic Improvement of Ministry of Agriculture, Beijing Key Laboratory of Crop Genetic Improvement, College of Agronomy and BiotechnologyChina Agricultural UniversityBeijingChina
2.Key Laboratory of Bioinformatics and Bioinformatics Division of Ministry of Education, Tsinghua National Laboratory for Information Sciences and Technology, Department of AutomationTsinghua UniversityBeijingChina
3.Division of Statistical GenomicsWashington University School of MedicineSt LouisUSA