Sharma Rajan, Upadhyaya H D, Manjunatha S V, Rai K N, Gupta S K, Thakur R P
International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502324, Andhra Pradesh, India.
Plant Dis. 2013 Feb;97(2):189-195. doi: 10.1094/PDIS-05-12-0481-RE.
Blast, also known as leaf spot, caused by Pyricularia grisea (teleomorph: Magnaporthe grisea), has emerged as a serious disease affecting both forage and grain production in pearl millet in India. Pathogenic variation was studied in a greenhouse using 25 M. grisea isolates collected from four major pearl-millet-growing states in India (Rajasthan, Haryana, Maharashtra, and Uttar Pradesh) on 10 pearl millet genotypes (ICMB 02444, ICMB 02777, ICMB 06444, ICMB 93333, ICMB 96666, ICMB 97222, ICMB 99444, 863B, ICMR 06222, and ICMB 95444). Differential reactions to the test isolates were recorded on ICMB 02444, ICMB 93333, ICMB 97222, 863B, and ICMR 06222. The 25 isolates were grouped into five different pathotypes based on their reaction types (virulent = score ≥ 4 and avirulent = score ≤ 3 on a 1-to-9 scale). For the identification of resistance sources, a pearl millet mini-core comprising 238 accessions was evaluated under greenhouse conditions against five M. grisea isolates (Pg118, Pg119, Pg56, Pg53, and Pg45) representing the five pathotypes. Of 238 accessions, 32 were found to be resistant to at least one pathotype. Resistance to multiple pathotypes (two or more) was recorded in several accessions, while three accessions (IP 7846, IP 11036, and IP 21187) exhibited resistance to four of the five pathotypes. Four early-flowering (≤50 days) blast-resistant mini-core accessions (IP 7846, IP 4291, IP 15256, and IP 22449) and four accessions (IP 5964, IP 11010, IP 13636, and IP 20577) having high scores (≥7) for grain and green fodder yield potential and overall plant aspect were found to be promising for utilization in pearl millet improvement programs. Identification of five pathotypes of M. grisea and sources of resistance to these pathotypes will provide a foundation for breeding for blast resistance in pearl millet in India.
稻瘟病，也称为叶斑病，由稻瘟病菌（有性型：灰梨孢菌）引起，已成为影响印度珍珠粟饲料和谷物生产的一种严重病害。在温室中，使用从印度四个主要珍珠粟种植邦（拉贾斯坦邦、哈里亚纳邦、马哈拉施特拉邦和北方邦）收集的25个稻瘟病菌分离株，对10个珍珠粟基因型（ICMB 02444、ICMB 02777、ICMB 06444、ICMB 93333、ICMB 96666、ICMB 97222、ICMB 99444、863B、ICMR 06222和ICMB 95444）进行了致病性变异研究。在ICMB 02444、ICMB 93333、ICMB 97222、863B和ICMR 06222上记录了对测试分离株的差异反应。根据它们的反应类型（强毒株=评分≥4，无毒株=评分≤3；评分范围为1至9），将这25个分离株分为五种不同的致病型。为了鉴定抗性来源物，在温室条件下对一个由238份种质组成的珍珠粟微型核心种质库，针对代表五种致病型的五个稻瘟病菌分离株（Pg118、Pg119、Pg56、Pg53和Pg45）进行了评估。在238份种质中，发现32份对至少一种致病型具有抗性。在几份种质中记录到对多种致病型（两种或更多）的抗性，而有三份种质（IP 7846、IP 11036和IP 21187）对五种致病型中的四种表现出抗性。发现四个早熟（≤50天）抗稻瘟病的微型核心种质（IP 7846、IP 4291、IP 15256和IP 22449）以及四个在谷物和绿色饲料产量潜力以及整体植株外观方面得分较高（≥7）的种质（IP 5964、IP 11010、IP 13636和IP 20577），有望用于印度珍珠粟改良计划。鉴定稻瘟病菌的五种致病型以及对这些致病型的抗性来源物，将为印度珍珠粟抗稻瘟病育种奠定基础。
