Orateur
Description
Rice is one of the top cereals consumed worldwide, but intensive farming practices such as excessive pesticide and fertilizer use jeopardize ecosystems by decimating vital pollinators and soil microorganisms. To ensure sustainable food security, agriculture must shift toward biological controls and climate-resilient crop varieties. While traditional gene selection for yield and stress tolerance faces limitations under a changing climate, identifying Quantitative Trait Loci (QTLs) across diverse environments enables the development of stable, resilient varieties. This is particularly crucial for overcoming major diseases like rice blast (Pyricularia oryzae).
A performant rice variety should have a high-yielding and resistant genotype.
This study utilizes a high-density bin map to develop high-yielding, blast-resistant rice varieties by detecting QTLs and major resistance (R) genes. Specifically, we aim to identify positively associated QTLs for both traits and clarify selection approaches in hybrid rice by evaluating the direct and indirect contributions of morphological traits to yield via path analysis.
A population of 256 recombinant inbred lines (RILs) was developed from a cross between two indica rice restorer lines, Dan 71 (D71) and Zhonghui 161 (ZH161), which contrast in the blast resistance regions Pi26, Pi25, Pib, and Pita.
Most yield-related QTLs were mapped in clusters. Among these, 12 grain weight and size clusters aligned with or were adjacent to previously cloned genes for those traits. Conversely, four grain weight and size clusters (qGL4/qGW4.1, qGL11.2/qRLW11, qTGW11/qGW11, and qGL12/qGW12/qRLW12) were newly identified in novel genomic regions. While parental yields remained stable, RIL lines 72 (GY = 78.5 g) and 154 (GY = 75.7 g) significantly outperformed the most productive parent. These two lines are promising candidates for developing stable, high-yielding varieties, and cloning these newly detected QTLs is recommended for novel gene discovery.