Fine Mapping of a Novel Major Quantitative Trait Locus, , That Controls Panicle Apical Abortion in Rice.

The panicle apical abortion (PAA) causes severe yield losses in rice production, but details about its development and molecular basis remain elusive. Here, we detected PAA quantitative trait loci (QTLs) in three environments using a set of chromosome segment substitution lines (CSSLs) that was constructed with Changhui121 as the recurrent parent and Koshihikari as the donor parent. First, we identified a novel major effector quantitative trait locus, , and selected a severe PAA line, CSSL176, which had the highest PAA rate among CSSLs having Koshihikari segments at this locus. Next, an F population was constructed from a cross between CSS176 and CH121. Using F to make recombinantion analysis, was mapped to an 73.8-kb interval in chromosome 7. Among nine candidate genes within this interval, there isn't any known genes affecting PAA. According to the gene annotation, gene expression profile and alignment of genomic DNA, and were predicted as putative candidate genes of . Our study provides a foundation for cloning and functional characterization of the target gene from this locus.