Scholarlink

<p>Anaerobic germination (AG) tolerance is vital for establishing direct-seeded rice (DSR) under early-season flooding. We evaluated 181 <i>aus</i> rice accessions under severe tray hypoxia and field-simulated puddled tanks to characterize phenotypic variation and map genomic regions controlling AG traits. Under AG, germination percentage (GRP) was considerably reduced recoding 44% in tray and 53% in tank. Strong genotype × environment interactions were observed; for example, 17 accessions exceeded 80% GRP in trays compared to only four in tanks, yielding a weak cross-environment correlation (<i>R</i><sup><i>2</i></sup> = 0.04). Considerable genotypic variation was recorded for germination speed, coleoptile length and seedling vigour. Despite this variance, multivariate analysis identified highly stable elite donors, notably ‘Karangi’, ‘Natel boro’, and ‘Kharsu 80’, which maintained superior AG performance across both environments. Genome-wide association studies (GWAS) utilizing ~ 458&#xa0;K SNPs identified 84 quantitative trait loci (QTLs) governing GRP, AG index, mean germination rate (MGR), and coleoptile length (LtD7). These QTLs mapped to core survival pathways, co-localizing with known key regulators including <i>OsTPP7</i>, <i>SnRK1A OsETOL1</i>, and <i>OsEE1</i>, along with many candidate genes. Haplotype mining revealed significant allelic functional diversity; while the predominant <i>OsTPP7</i> Hap-1 provided a robust genetic foundation for initial anaerobic survival, <i>OsEE1</i> Hap-2 specifically drove rapid coleoptile elongation and was notably enriched in the K2 ancestry subgroup, linking population structure to phenotypic resilience. Together, the identified QTLs, promising donors, and functionally distinct haplotypes will accelerate the targeted utilization of <i>aus</i> cultivars for AG tolerance, providing immediate genetic resources for marker-assisted allele pyramiding to develop climate-resilient, high-vigour DSR varieties.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Genetic Dissection of Germination Potential and Coleoptile Elongation in aus Rice Under Anaerobic Conditions: GWAS and Donor Mining for Climate-Resilient Direct Seeded Rice

  • 期刊论文

  • 发表日期：

    2026年6月26日

查看全文
  • Nayanika Guha,
  • Anima Mahato,
  • Sougata Bhattacharjee,
  • Koushik Chakraborty,
  • Amrita Banerjee,
  • Nimai Prasad Mandal,
  • Somnath Roy

摘要

Anaerobic germination (AG) tolerance is vital for establishing direct-seeded rice (DSR) under early-season flooding. We evaluated 181 aus rice accessions under severe tray hypoxia and field-simulated puddled tanks to characterize phenotypic variation and map genomic regions controlling AG traits. Under AG, germination percentage (GRP) was considerably reduced recoding 44% in tray and 53% in tank. Strong genotype × environment interactions were observed; for example, 17 accessions exceeded 80% GRP in trays compared to only four in tanks, yielding a weak cross-environment correlation (R2 = 0.04). Considerable genotypic variation was recorded for germination speed, coleoptile length and seedling vigour. Despite this variance, multivariate analysis identified highly stable elite donors, notably ‘Karangi’, ‘Natel boro’, and ‘Kharsu 80’, which maintained superior AG performance across both environments. Genome-wide association studies (GWAS) utilizing ~ 458 K SNPs identified 84 quantitative trait loci (QTLs) governing GRP, AG index, mean germination rate (MGR), and coleoptile length (LtD7). These QTLs mapped to core survival pathways, co-localizing with known key regulators including OsTPP7, SnRK1A OsETOL1, and OsEE1, along with many candidate genes. Haplotype mining revealed significant allelic functional diversity; while the predominant OsTPP7 Hap-1 provided a robust genetic foundation for initial anaerobic survival, OsEE1 Hap-2 specifically drove rapid coleoptile elongation and was notably enriched in the K2 ancestry subgroup, linking population structure to phenotypic resilience. Together, the identified QTLs, promising donors, and functionally distinct haplotypes will accelerate the targeted utilization of aus cultivars for AG tolerance, providing immediate genetic resources for marker-assisted allele pyramiding to develop climate-resilient, high-vigour DSR varieties.