QTL mapping for heading date and plant height using a RIL population in rice in different photoperiod environments

Abstract

Heading date determines rice seasonal and regional adaptation, while plant height is an important trait related to rice lodging resistance. In this study, a recombinant inbred line population was used to detect quantitative trait loci (QTLs) for both traits in long-day (LD) and short-day (SD) environments. Three and two QTLs for heading date were detected in LD and SD environments, respectively. Notably, qHD8 and qHD10 were commonly detected in both environments. Five and four QTLs for plant height were identified in LD and SD environments, respectively. Among them, qPH3, qPH5 and qPH6 showed no pleiotropic effects on heading date and were detected in both environments. These three QTLs are considered to be the primary targets for improving rice plant height. Additionally, two genomic regions exhibited pleiotropic effects on both heading date and plant height. The alleles delayed the heading date while simultaneously increasing plant height. This study indicated that most QTLs for heading date are sensitive to photoperiod and have pleiotropic effects on plant height, thereby complicating their application in breeding programs. These findings provide useful information for the breeding of rice varieties with desired heading dates and plant heights.

Keywords

• gene-environment interaction
• genetic mapping
• oryza sativa l.
• pleiotropic effect
• quantitative trait loci