Substitution Mapping of the Major Quantitative Trait Loci Controlling Stigma Exsertion Rate from Oryza glumaepatula

Abstract

Background Stigma exsertion rate (SER) is a key determinant for the outcrossing ability of male sterility lines (MSLs) in hybrid rice seed production. In the process of domestication, the outcrossing ability of cultivated rice varieties decreased, while that of wild Oryza species kept strong. Here, we detected the quantitative trait loci (QTLs) controlling SER using a set of single-segment substitution lines (SSSLs) derived from O. glumaepatula, a wild Oryza species. Results Seven QTLs for SER were located on 5 chromosomes. qSER-1a and qSER-1b were located on chromosome 1. qSER-3a and qSER-3b were mapped on chromosome 3, and qSER-3b was further located at an estimated interval of 898.8 kb by secondary substitution mapping. qSER-5, qSER-9 and qSER-10 were identified on chromosomes 5, 9 and 10, respectively, and qSER-9 was delimited to an estimated region of 551.9 kb by secondary substitution mapping. The additive effects of the 7 QTLs ranged from 10.6% to 14.8%, which were higher than those of most loci for SER reported previously. Conclusions qSER-1a and qSER-1b are novel loci for SER on chromosome 1. All of the 7 QTLs have major effects on SER. The major QTLs of SER will help to develop MSLs with strong outcrossing ability.

Fine mapping of two grain chalkiness QTLs sensitive to high temperature in rice

“…DNA samples were amplified by PCR method. PCR products were separated by gel electrophoresis on 6% denatured PAGE and detected by the silver staining method (Tan et al 2020 ).…”

“…The NILs were developed from F 2:3 populations derived from the crosses. The minimum, maximum and estimated lengths of a substitution segment were estimated by the positions of markers (Tan et al 2020 ). The QTLs were located by substitution mapping (Eshed and Zamir 1995 ; Tan et al 2020 ).…”

“…The minimum, maximum and estimated lengths of a substitution segment were estimated by the positions of markers (Tan et al 2020 ). The QTLs were located by substitution mapping (Eshed and Zamir 1995 ; Tan et al 2020 ). When PGC showed significant difference between SSSL genotype and HJX74 genotype, a QTL for PGC was detected on the substitution segment of SSSL.…”

“…When PGC showed significant difference between SSSL genotype and HJX74 genotype, a QTL for PGC was detected on the substitution segment of SSSL. When multiple substitution segments in NILs with target trait overlapped, the QTL was located in the overlapping region (Tan et al 2020 ). Additive effect of a QTL was defined as the phenotypic difference between SSSL and HJX74 (Zhou et al 2020 ).…”

“…Recently, the SSSLs were used to detect QTLs controlling stigma exsertion rate (SER) of rice. A total of 11 QTLs for SER were mapped on 6 chromosomes of rice genome (Tan et al 2020 ; Tan et al 2021 ). In present study, two QTLs for grain chalkiness on chromosomes 9 and 11, qPGC9 and qPGC11 , were fine mapped.…”