1- Department of Genetics and Plant Breeding, Agricultural College, Bapatla, ANGRAU,Andhra Pradesh, India – 522 101
2- Department of Molecular Biology and Biotechnology, RARS, Lam, ANGRAU, Andhra Pradesh, India – 522 034 , v.roja@angrau.ac.in
3- Department of Genetics and Plant Breeding,Agricultural College, Bapatla, ANGRAU, Andhra Pradesh, India – 522 101
4- Department of Plant Pathology,Agricultural College, Bapatla, ANGRAU, Andhra Pradesh, India – 522 101
5- Department of Molecular Biology and Biotechnology, RARS, Lam, ANGRAU,Andhra Pradesh, India – 522 034
Abstract: (100 Views)
Bacterial leaf blight (BLB) is one of the most devastating diseases of rice (Oryza sativa L.), causing substantial yield losses and posing a serious threat to food and livelihood security across rice-dependent regions of Asia and Africa. In this study, 71 rice genotypes developed through crosses among elite and improved lines, were evaluated for bacterial leaf blight (BLB) resistance using artificial clip inoculation at maximum tillering stage, with resistant (Improved Samba Mahsuri) and susceptible (Taichung Native-1, Krishnaveni) checks, under field conditions at Bapatla and Maruteru, Andhra Pradesh, India. Phenotypic screening identified nine genotypes exhibiting disease reaction towards resistance (disease scores 1–3) at both sites. Molecular screening for five BLB resistance (R) genes, Xa21, xa13, xa5, Xa4, and Xa2, revealed BPT-3170 carried four R genes (xa13+xa5+Xa4+Xa2), while eight genotypes had two genes, and 30 genotypes carried one gene. Phylogenetic analysis using 14 R gene-linked markers grouped the genotypes into three major clusters. BPT-3170 exhibited phenotypic resistance along with multiple R genes, indicating its potential to confer broad spectrum resistance and can serve as a valuable donor in BLB resistance breeding. The study also revealed the breakdown of single-gene resistance and low frequencies of xa5, xa13, and Xa21. These findings highlight the importance of pyramiding multiple R genes to achieve durable resistance against BLB.
Article Type:
Original Research |
Subject:
Molecular Genetics Received: 2024/07/19 | Accepted: 2024/01/11