Functional Bph14 from Rathu Heenati promotes resistance to BPH at the early seedling stage of rice (Oryza sativa L.) as revealed by QTL-seq

Key messageA QTL associated with BPH resistance at the early seedling stage was identified on chromosome 3. Functional Bph14 in Rathu Heenati was associated with BPH resistance at the early seedling stage.Brown planthopper (BPH; Nilaparvata lugens Stal) is considered the most important rice pest in many Asian countries. Several BPH resistance genes have previously been identified. However, there are few reports of genes specific for BPH resistance at the early seedling stage, a crucial stage for direct-seeding cultivation. In this study, we performed a QTL-seq analysis using two bulks (20 F-2 lines in each bulk) of the F-2 population (n = 300) derived from a cross of Rathu Heenati (RH) x HCS-1 to identify QTL/genes associated with BPH resistance at the early seedling stage. An important QTL was identified on chromosome 3 and Bph14 was identified as a potential candidate gene based on the differences in gene expression and sequence variation when compared with the two parents. All plants in the resistant bulks possessed the functional Bph14 from RH and all plants in the susceptible bulk and HCS-1 contained a large deletion (2703 bp) in Bph14. The functional Bph14 gene of RH appears to be important for BPH resistance at the early seedling stage of rice and could be used in conjunction with other BPH resistance genes in rice breeding programs that confer resistance to BPH at the early and later growth stages.

Automated summary

In this study, a QTL associated with BPH resistance at the early seedling stage was identified on chromosome 3 using QTL-seq analysis. Bph14 was identified as a potential candidate gene based on gene expression and sequence variation differences compared with the parents. This functional gene of Bph14 from RH is important for BPH resistance at the early seedling stage and could be used in breeding programs to enhance BPH resistance in rice at both early and later growth stages.