Abstract:

: Plant height (PH) is one of the most important agronomic traits determining plant architecture in rice. To investigate the genetic basis of plant height in the high-yielding hybrid rice variety Nei2You No.6, recombinant inbred sister lines (RISLs) were used to map quantitative trait loci (QTL) over four years. A total of 19 minor/medium-effect QTLs were mapped on eleven chromosomes except chromosome 10, totally explaining 44.61–51.15% phenotypic variance in four environments. Among these, qPH-1a, qPH-1b, qPH-2b, qPH-3b, qPH-6, and qPH-7b were repeatedly detected over four years. Among these, the qPH-6 was mapped to an interval of 22.11–29.41 Mb on chromosome 6L, which showed the highest phenotypic variation explained (PVE) of 10.22–14.05% and additive effect of 3.45–4.63. Subsequently, evaluation of near isogenic lines (NILs) showed that the qPH-6 allele from the restorer line (R8006) could positively regulate plant height, resulting in an 18.50% increase in grain yield. These results offered a basis for further mapping of qPH-6 and molecular breeding in improving plant architecture in rice.

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