DETERMINATION OF SOURCE OF RESISTANCE IN WHEAT AGAINST BACTERIAL LEAF STREAK AND MORPHO-BIOCHEMICAL CHARACTERIZATION OF XANTHOMONAS TRANSLUCENS PV. UNDULOSA

Abstract

Current research effort was directed focusing on evaluating the wheat germplasm for determination of source of resistance against the bacterial leaf streak (BLS) disease and the morpho-biochemical characterization of Xanthomonas translucens pv. undulosa (Xtu), the causative agent of bacterial leaf streak of wheat. The bacterium Xtu showed yellow, mucoid, circular and convex shaped growth when cultured on artificial growth media (NA). Gram staining, Catalase, KOH and Kovacs oxidase tests were employed that confirmed the Xtu as gram negative (-ve) bacterium. Fifteen wheat varieties/advanced lines were evaluated against BLS disease employing Randomized Complete Block Design (RCBD) to estimate the disease incidence over two years (2023 and 2024). Screening results for both years revealed that only one advanced line (PBG Line 8) expressed highly resistant response while two varieties PBG Line 1 and NARC-2008 exhibited resistant response. Two advanced lines (PBG Line 2 and PBG Line 5) were observed as moderately resistant while, moderately susceptible response was shown by FSD-2008, PBG Line 4, Ujala-2016, PBG Line 3, PBG Line 7 and PBG Line 6. The remaining varieties/advanced lines Umeed-2014, Zincol 2015, PBG Line 9 and PBG Line 10 showed susceptible response. The successful screening of wheat germplasm for resistance to bacterial leaf streak disease is an important source of resistance for breeding programs. Future research should prioritize leveraging this resource to develop enhanced cultivars and strengthen integrated management strategies for bacterial leaf streak disease (BLS). This approach will support the advancement of disease-resistant varieties and promote more effective, sustainable disease management solutions.