Scholarlink

<p>Blast disease, caused by <i>Magnaporthe oryzae</i>, significantly threatens global rice production, causing 10–35% yield losses annually. In Iran, heavy reliance on chemical fungicides has led to environmental pollution and fungal resistance, underscoring the need for genetically resistant rice varieties. Although approximately 100 blast resistance genes are known globally, their presence in Iranian rice germplasm remains unstudied. This research screened 60 Iranian rice genotypes for six broad-spectrum blast resistance genes (<i>Pi5</i>, <i>Pi1</i>, <i>Pi54</i>, <i>Pi2</i>, <i>pi55</i>, and <i>Pid2</i>) using functional markers via PCR and evaluated their leaf blast resistance to support breeding durable resilient varieties. Phenotypic evaluation classified 38% of genotypes as highly resistant, 40% as susceptible, and 22% as moderately resistant. Molecular analysis showed varied gene frequencies, with <i>Pid2</i> present in 88.9% and <i>Pi2</i> in only 6.67% of genotypes. The Zenith genotype, carrying five of six resistance genes (except <i>Pi2</i>), exhibited the highest resistance. The <i>Pi54</i> gene was strongly associated with low disease severity. Stepwise regression identified <i>Pi54</i>, <i>Pi2</i>, and <i>pi55</i> as key markers, explaining 60.1% of phenotypic variance. Cluster analysis grouped genotypes into three clusters, with Cluster I containing the most resistant ones. Principal component analysis highlighted <i>Pi1</i> and <i>Pi54</i> as major contributors to genetic variation, explaining 26.82% and 22.02% of variance, respectively. This novel study reveals significant genetic diversity and blast resistance potential in Iranian rice germplasm, with genotypes like Zenith serving as valuable resources for breeding programs. The prominence of <i>Pi54</i> offers a foundation for developing durable blast-resistant rice varieties, reducing chemical dependency and enhancing food security in Iran.</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

Identification of new genetic resources for broad-spectrum blast resistance genes in Iranian rice germplasm

  • 期刊论文

  • 发表日期：

    2025年11月5日

查看全文
  • Mostafa Modarresi,
  • Hadis Shahbazi,
  • Alireza Tarang,
  • Farzin Pouramir,
  • Maryam Hosseini Chaleshtori,
  • Fatemeh Habibi

摘要

Blast disease, caused by Magnaporthe oryzae, significantly threatens global rice production, causing 10–35% yield losses annually. In Iran, heavy reliance on chemical fungicides has led to environmental pollution and fungal resistance, underscoring the need for genetically resistant rice varieties. Although approximately 100 blast resistance genes are known globally, their presence in Iranian rice germplasm remains unstudied. This research screened 60 Iranian rice genotypes for six broad-spectrum blast resistance genes (Pi5, Pi1, Pi54, Pi2, pi55, and Pid2) using functional markers via PCR and evaluated their leaf blast resistance to support breeding durable resilient varieties. Phenotypic evaluation classified 38% of genotypes as highly resistant, 40% as susceptible, and 22% as moderately resistant. Molecular analysis showed varied gene frequencies, with Pid2 present in 88.9% and Pi2 in only 6.67% of genotypes. The Zenith genotype, carrying five of six resistance genes (except Pi2), exhibited the highest resistance. The Pi54 gene was strongly associated with low disease severity. Stepwise regression identified Pi54, Pi2, and pi55 as key markers, explaining 60.1% of phenotypic variance. Cluster analysis grouped genotypes into three clusters, with Cluster I containing the most resistant ones. Principal component analysis highlighted Pi1 and Pi54 as major contributors to genetic variation, explaining 26.82% and 22.02% of variance, respectively. This novel study reveals significant genetic diversity and blast resistance potential in Iranian rice germplasm, with genotypes like Zenith serving as valuable resources for breeding programs. The prominence of Pi54 offers a foundation for developing durable blast-resistant rice varieties, reducing chemical dependency and enhancing food security in Iran.