Genetic Diversity of Rice Bacterial Leaf Blight Pathogen, Xanthomonas oryzae pv. oryzae in Godavari Zone of Andhra Pradesh, India
Pasam. Shanmuki Shirisha
*
Agricultural College, Bapatla, India.
M. Ramabhadra Raju
Agricultural Research Station, Peddapuram, India.
P. Madhusudhan
Agricultural Research Station, Nellore, India.
T. Srinivas
RARS, Maruteru, India.
Sandhya Rani
Agricultural College, Bapatla, India.
*Author to whom correspondence should be addressed.
Abstract
Bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the major biotic constraints limiting yields in paddy in Andhra Pradesh. The present study was conducted at ANGRAU – Regional Agricultural Research Station, Maruteru, Andhra Pradesh, during Kharif 2024 to understand genetic variability among twenty Xoo isolates collected from five districts of the Godavari zone in Andhra Pradesh. Bacterial genomic DNA was extracted, analysed for purity and concentration, followed by PCR amplification using universal 16S rDNA and Xoo-specific JEL marker primers. Most virulent BLB isolate (Xoo7) in the present study was characterised as the Xanthomonas oryzae pv. oryzae by using universal primer 16S rDNA sequence. Genetic diversity assessed using JEL primers (targeting IS1112 sequence) and UPGMA clustering analysis revealed considerable genetic variability among the twenty Xoo isolates; the isolates were grouped in two major clades in the dendrogram. The clustering pattern corresponded with geographical origin and rice cultivars, suggesting localized adaptation. These findings offer valuable insights into the pathogen’s population structure and have implications for disease management strategies and breeding programs.
Keywords: Rice, genetic diversity, BLB, Xanthomonas oryzae pv. oryzae