Studies of Parasitism and Diversity Of Xanthomonas Oryzae Pathovars on Rice in Marathwada Region

Abstract

The genus Xanthomonas is a diverse and economically important group of bacterial newlinepathogens, belonging to the gamma-subdivision of the Proteobacteria consist of yellow newlinepigmented bacteria almost all being plant pathogen. The genus Xanthomonas is divided newlineinto 120 closely related forms called pathovars. Pathovars are distinguished by their plant newlinehost range generally one pathovar can attack only a narrow of related plants. Species and newlinepathovars of Xanthomonas have been reported to cause disease in at least 124 newlinemonocotyledons and 268 dicotyledons. Species of Xanthomonas infects a large numbers newlineof plants which include wild plant, ornamental plant, crop plant etc. Species of newlineXanthomonas incites a wide range of symptoms in the host plant. newline Rice is a good source of energy as the complex carbohydrates as well as several newlineessential nutrients are present in Rice. Rice is the staple food for more than half the newlineworld s population, especially Asia. Rice is the most extensively grown crop of India and newlineis grown in almost all parts of the country like A.P., M.P., U.P., Punjab, Orissa, Tamil newlinenadu and Maharashtra. In Maharashtra, it is grown under diverse agro-ecological condition newlineas irrigated rice, upland rice, lowland rice, etc. in the region of Konkan, Vidherbha, newlineWestern Maharashtra and Marathwada. In Marathwada rainfed upland ecosystem is present newlinein Nanded, Latur, Hingoli, Beed, Jalna, Parbhani, Aurangabad and Osmanabad districts. newline Rice production is mostly affected by pathogen of fungal, viral and bacterial origin. newlineBacterial Leaf blight (BLB) on rice caused by pathogen - Xanthomonas oryzae pv. oryzae newlineis one of the major disease of Rice globally in the irrigated agro-ecosystem. BLB is a newlinevascular disease resulting in a systemic infection that produces greenish yellow, pale newlinetissue and then drying between diseased tissue and healthy tissue forming dark brown wavy newlinestructures. The water absorbent stripes turn to dark green and brown. newlineAbstract newline newlineXV newline newline The pathogen exhibits significant diversity among isolates. There is remark