Abstract: Rice panicle traits have a distinct effect on yield, and the exploration and research of related genes plays a crucial role in ensuring national food security. In this study, we used the indica rice HZ, the japonica rice Nekken2 and 120 RILs populations constructed from them as experimental materials to measure panicle length, grain number per panicle, seed setting rate, stigma exsertion rate, number of primary branches and other panicle traits. We combined the high-density genetic map for QTL mapping. A total of 31 QTLs were detected on chromosomes 1, 2, 3, 4, 5, 6, 10 and 11, among which 2 LOD values were as high as 5.45 and 5.28, respectively. By analyzing the candidate genes in the QTLs interval, the related genes that may affect the panicle traits were screened out, and qRT-PCR was used for gene expression analysis, which showed that LOC_Os05g05490, LOC_Os05g06150, LOC_Os03g11700, LOC_Os03g12430, LOC_Os05g28720, LOC_Os05g30890, LOC_Os05g31740 and LOC_Os02g17880 were significantly different in expression level between the parents. In these genes, the first five genes encode tripartite pentapeptide repeat proteins, while the latter three genes encode glycosyltransferases. The study identified 31 QTLs related to panicle traits , which laid a theoretical basis for  further localization and cloning of related genes and breeding new high-yield rice varieties.

Key words: Oryza sativa (rice), panicle traits, QTL mapping, candidate genes, high-yield