QTL-seq reveals genomic regions associated with spikelet fertility in response to a high temperature in rice (Oryza sativa L.)
The QTL-seq approach was used to identify QTLs for spikelet fertility under heat stress in rice. QTLs were detected on chromosomes 1, 2 and 3.
Rice is a staple food of more than half of the global population. Rice production is increasingly affected by extreme environmental fluctuations caused by climate change. Increasing temperatures that exceed the optimum temperature adversely affect rice growth and development, especially during reproductive stages. Heat stress during the reproductive stages has a large effect on spikelet fertility; hence, the yield decreases. To sustain rice yields under increasing temperatures, the development of rice varieties for heat tolerance is necessary. In this study, we applied the QTL-seq approach to rapidly identify QTLs for spikelet fertility under heat stress (air temperature of 40–45 °C) based on two DNA pools, each consisting of 25 individual plants that exhibited a heat-tolerant or heat-sensitive phenotype from an F2 population of a cross between M9962 (heat tolerant) and Sinlek (heat sensitive). Three QTLs, qSF1, qSF2 and qSF3, were detected on chromosomes 1, 2 and 3, respectively, according to the highest contrasting SNP index between the two bulks. The QTLs identified in this study were found to overlap or were linked to QTLs previously identified in other crosses using conventional QTL mapping. A few highly abundant and anther-specific genes that contain nonsynonymous variants were identified within the QTLs and were proposed to be potential candidate genes. These genes could be targets in rice breeding programs for heat tolerance.
KeywordsRice Heat tolerance QTL-seq Bulk-segregant analysis
Quantitative trait loci
QTL of spikelet fertility
Mega base pair
This work was supported by the Agricultural Research Development Agency (ARDA) (Grant No. PRP5905021150).
Author contribution statement
SW, CM, TT, AV and SA conceived and designed the experiment. PN, SC and VR conducted the experiments. SW and CS analyzed the data. SW, SA and PN wrote the manuscript. SW and SA revised the final version of the paper. All authors approved the final version of the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflicts of interest.
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