Multi-Environmental Genetic Analysis of Grain Size Traits Based on Chromosome Segment Substitution Line in Rice (Oryza sativa L.)

Grain size traits are critical agronomic which directly determine grain yield, but the genetic bases of these still not well understood. In this study, a total 154 chromosome segment substitution lines (CSSLs) population derived from cross between japonica variety Koshihikari and an indica Nona Bokra was used to investigate length (GL), width (GW), length-width ratio (LWR), perimeter (GP), area (GA), thousand weight (TGW) under four environments. QTL mapping analysis six performed by IciMapping 4.2 with inclusive composite interval (ICIM) model. A 64 QTLs were identified for traits, mapped chromosomes 1, 2, 3, 4, 6, 7, 8, 10, 11, 12 accounted 1.6%–27.1% phenotypic variations. Among QTLs, thirty-six loci novel seven One locus containing known gene, qGL3/GL3.1/OsPPKL1, also have been found. Moreover, five pairs digenic epistatic interactions except GL GP. These findings will facilitate fine candidate gene pyramiding genetically improve yield in rice.