Morphological and Pathogenic Variability among Isolates of Xanthomonas oryzae pv. oryzae, Causal Agent of Bacterial Leaf Blight of Rice from Godavari Zone of Andhra Pradesh

 

Shanmuki Shirisha P¹*, Ramabhadra Raju M², Madhusudhan P³, Sandhya Rani C4, Srinivas T5, Bhuvaneswari V6 and Deepthi Priya B7

1     Department of Plant Pathology, Agricultural College, Bapatla (ANGRAU), Andhra Pradesh
2,7  Department of Plant Pathology, ARS, Peddapuram (ANGRAU), Andhra Pradesh
3     Department of Plant Pathology, ARS, Nellore
4     Department of Entomology, Agriculture College, Bapatla
5     Department of Genetics and Plant Breeding RARS, Maruteru
6     Department of Plant Pathology RARS, Maruteru

*Corresponding author Email: sirishapasam038@gmail.com

Volume 18-(2), 2025   ;  https://doi.org/10.58297/PBZA1175   Click here for Pdf

Received: 25th August, 2025; Accepted: 15th October, 2025
 
Abstract

Bacterial leaf blight (BLB) of rice, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a major biotic constraint in rice cultivation and is widespread across India. Present study was undertaken to assess morphological, biochemical and pathogenic variability among the twenty isolates of Xanthomonas oryzae pv. oryzae collected from major rice growing areas of Godavari zone of Andhra Pradesh. Variation in colony size, colour, margin, appearance, texture and pigmentation were observed among the isolates. However, all the isolates were gram negative and tested positive for KOH test, catalase test, and starch hydrolysis test while, tested negative for oxidase test. In the pot study, Xoo isolates varied in their pathogenic ability in terms on lesion development post artificial inoculation (leaf clip method) on the three rice cultivars viz., BPT-5204, TN-1, and MTU 7029 under study. Xoo isolates from Konaseema district were found more virulent followed by isolates from Kakinada, West Godavari, Eluru and East Godavari districts.

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