Sakhale Sandeep A, Yadav Shailesh, Clark Lindsay V, Lipka Alexander E, Kumar Arvind, Sacks Erik J
Department of Crop Sciences, University of Illinois Urbana-Champaign, Urbana, IL, United States.
International Rice Research Institute (IRRI), Los Baños, Philippines.
Front Plant Sci. 2023 Jun 12;14:1172816. doi: 10.3389/fpls.2023.1172816. eCollection 2023.
Dry direct-seeded rice (dry-DSR) is typically sown deeply to circumvent the need for irrigation, and thus seedling emergence is a crucial trait affecting plant stand and yield. To breed elite cultivars that use less water and are climate-resilient, an understanding of the genomic regions and underlying genes that confer emergence in deeply sown dry-DSR would be highly advantageous. A combined diversity panel of 470 rice accessions (RDP1 plus aus subset of 3K RGP) was evaluated with 2.9 million single nucleotide polymorphisms (SNPs) to identify associations with dry-DSR traits in the field and component traits in a controlled-environment experiment. Using genome-wide association study (GWAS) analyses, we identified 18 unique QTLs on chromosomes 1, 2, 4, 5, 6, 7, 9, 10, and 11, explaining phenotypic variance ranging from 2.6% to 17.8%. Three QTLs, namely, , , and , were co-located with previously reported QTLs for mesocotyl length. Among the identified QTLs, half were associated with the emergence of aus, and six were unique to the aus genetic group. Based on functional annotation, we identified eleven compelling candidate genes that primarily regulate phytohormone pathways such as cytokinin, auxin, gibberellic acid, and jasmonic acid. Prior studies indicated that these phytohormones play a critical role in mesocotyl length under deep sowing. This study provides new insight into the importance of aus and as desirable genetic resources to mine favorable alleles for deep-sowing tolerance in rice. The candidate genes and marker-tagged desirable alleles identified in this study should benefit rice breeding programs directly.
旱直播水稻(dry-DSR)通常深播以避免灌溉需求,因此幼苗出土是影响植株密度和产量的关键性状。为培育用水少且适应气候的优良品种,了解在深播旱直播水稻中赋予出土能力的基因组区域和潜在基因将非常有利。对一个由470份水稻种质组成的联合多样性群体(RDP1加上3K RGP的奥里萨亚种子集)进行了评估,使用了290万个单核苷酸多态性(SNP),以确定在田间与旱直播水稻性状以及在控制环境试验中的组成性状的关联。通过全基因组关联研究(GWAS)分析,我们在第1、2、4、5、6、7、9、10和11号染色体上鉴定出18个独特的数量性状基因座(QTL),解释的表型变异范围为2.6%至17.8%。三个QTL,即 、 和 ,与先前报道的中胚轴长度QTL共定位。在鉴定出的QTL中,一半与奥里萨亚种的出土有关,六个是奥里萨遗传组特有的。基于功能注释,我们鉴定出11个引人注目的候选基因,它们主要调节细胞分裂素、生长素、赤霉素和茉莉酸等植物激素途径。先前的研究表明,这些植物激素在深播条件下对中胚轴长度起着关键作用。本研究为奥里萨亚种和 作为挖掘水稻深播耐受性有利等位基因的理想遗传资源的重要性提供了新的见解。本研究中鉴定出的候选基因和标记的理想等位基因应直接有利于水稻育种计划。