Abstract
QTLs for rice grain yield under reproductive stage drought stress (qDTY) identified earlier with low density markers have shown linkage drag and need to be fine mapped before their utilization in breeding programs. In this study, genotyping-by-sequencing (GBS) based high-density linkage map of rice was developed using two BC1F3 mapping populations namely Swarna*2/Dular (3929 SNPs covering 1454.68 cM) and IR11N121*2/Aus196 (1191 SNPs covering 1399.68 cM) with average marker density of 0.37 cM to 1.18 cM respectively. In total, six qDTY QTLs including three consistent effect QTLs were identified in Swarna*2/Dular while eight qDTY QTLs including two consistent effect QTLs were identified in IR11N121*2/Aus 196 mapping population. Comparative analysis revealed four stable and novel QTLs (qDTY2.4, qDTY3.3, qDTY6.3, and qDTY11.2) which explained 8.62 to 14.92% PVE. However, one of the identified stable grain yield QTL qDTY1.1 in both the populations was located nearly at the same physical position of an earlier mapped major qDTY QTL. Further, the effect of the identified qDTY1.1 was validated in a subset of lines derived from five mapping populations confirming robustness of qDTY1.1 across various genetic backgrounds/seasons. The study successfully identified stable grain yield QTLs free from undesirable linkages of tall plant height/early maturity utilizing high density linkage maps.
Highlights
QTL mapping for rice grain yield under reproductive stage drought stress tolerance Shailesh Yadav[1], Nitika Sandhu[1,2], Vikas Kumar Singh[3], Margaret Catolos1 & Arvind Kumar
Six qDTY QTLs including three consistent effect QTLs were identified in Swarna*2/Dular while eight qDTY QTLs including two consistent effect QTLs were identified in IR11N121*2/Aus 196 mapping population
The results indicated reduction in mean grain yield of parents and lines under reproductive stage drought (RS) compared with NS conditions in all the 12 experiments clearly indicating that drought stress imposed during 2016 wet season (WS) and 2017 dry season (DS) was effective
Summary
QTL mapping for rice grain yield under reproductive stage drought stress tolerance Shailesh Yadav[1], Nitika Sandhu[1,2], Vikas Kumar Singh[3], Margaret Catolos1 & Arvind Kumar. Genetic dissection of loci underlying drought tolerance in rice will accelerate the development of new varieties with enhanced grain yield under drought stress conditions In this context, discovery of grain yield QTLs under drought with large and consistent effect across the genetic backgrounds and environments is the most desirable step for its successful utilization in breeding programs. Rice breeding in the last 10 years at IRRI, Philippines has witnessed the identification of robust grain yield QTLs under drought stress conditions namely, qDTY1.11,2, qDTY2.13, qDTY3.13, qDTY12.14 using SSR markers. The incorporation of such positive qDTY alleles has been attempted recently into high yielding rice varieties popular in rainfed lowland and rainfed upland ecosystems in. Recent progress in generation sequencing has developed high-throughput
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
