Detection of Xanthomonas oryzae pv oryzae in BLB Paddy Seed Samples from Endemic Regions of Telangana State, India

Abstract

Bacterial Leaf Blight disease (BLB) in rice caused by Xanthomonas oryzae pv oryzae (Xoo), is one of the most economically important diseases causing epidemics globally, resulting in severe crop losses of 50% in addition to affecting the seed quality in Asia. In the present study, ten BLB affected paddy seed samples were collected during Kharif, 2021-22 from the farmer's fields of major BLB endemic districts viz., Nizamabad and Khammam of Telangana state. The collected BLB seed samples were subjected to different standard seed health tests (ISTA, 1996) for detection and isolation of Xoo. Among the different methods evaluated, the detection of Xoo from BLB affected seed samples was high in the Agar plate method followed by the test tube water agar method. However, the component plating method revealed that, of the different seed components, the per cent recovery of Xoo was high from the embryo followed by lemma, palea and endosperm indicating the systemic type of infection of Xoo. Further, the results of the paper towel method stated that of the ten BLB affected paddy seed samples collected, the seed samples of Govuru village (Nizamabad district) and Rejarla village (Khammam district) have recorded below Indian Minimum Seed Certification Standards i.e 77.00% and 79.25% of per cent seed germination compared to the seed samples of other locations.