~ 484 ~ The Pharma Innovation Journal 2023; 12(5): 484-491 ISSN (E): 2277-7695 ISSN (P): 2349-8242 NAAS Rating: 5.23 TPI 2023; 12(5): 484-491 © 2023 TPI www.thepharmajournal.com Received: 19-02-2023 Accepted: 23-03-2023 Lingaraj B Ph.D., Scholar, Department of Plant Pathology, College of Agriculture, UAS, Raichur, Karnataka, India MK Naik Director of Extension, UAS, Raichur, Karnataka, India Yenjerappa ST Professor and Head, Department of Plant Pathology, College of Agriculture, UAS, Raichur, Karnataka, India Ajithkumar K Scientist and Head, AICRP on Linseed, MARS, College of Agriculture, UAS, Raichur, Karnataka, India Pampanna Y Assistant Professor and Head, Horticulture Unit, MARS, College of Agriculture, UAS, Raichur, Karnataka, India Kisan B Assistant Professor, Department of Molecular Biology and Agricultural Biotechnology, College of Agriculture, UAS, Raichur, Karnataka, India Corresponding Author: Lingaraj B Ph.D., Scholar, Department of Plant Pathology, College of Agriculture, UAS, Raichur, Karnataka, India Screening of commercial cabbage cultivars for black rot resistance in Karnataka Lingaraj B, MK Naik, Yenjerappa ST, Ajithkumar K, Pampanna Y and Kisan B Abstract Black rot of cabbage caused by Xanthomonas campestris pv. campestris (Xcc) is one of the most damaging disease that significantly reduces cabbage yields globally. The introduction of disease-resistant cabbage cultivars could be a simple and cost-efficient way to stop this deadly disease. We screened 28 cabbage cultivars under greenhouse conditions and 26 cultivars under field conditions for two seasons (Kharif 2021 and rabi 2021-22). None of the cultivars were immune or resistant to black rot in both greenhouse and field conditions. Under greenhouse conditions, only the Hari Rani cultivar recorded a moderately resistant reaction with a disease severity of 29.60 and a minimum AUDPC of 140.60 compared to the other cultivars. Whereas, six cultivars showed a moderately susceptible reaction, 11 were susceptible, and 10 were highly susceptible to black rot. During field screening of cultivars (Kharif 2021) identifies Hari Rani was a moderately resistant hybrid with 30.37 per cent of disease severity whereas during rabi 2021-22 none of them were recorded to be moderately resistant. The cultivar NEON was recorded highly susceptible to black rot during rabi 2021-22 season with a disease severity of 77.77 per cent whereas none of them showed a highly susceptible reaction during Kharif 2021. Keywords: Black rot, Xcc, cabbage, cultivar, screening Introduction Cabbage (Brassica oleracea var. capitata L.) is considered as one of the most important vegetable, widely grown for its nutritional and health benefits (Lee et al. 2015) [9] . Black rot caused by the seed-borne bacterium Xcc, is one of the most devastating diseases of brassicas (Vicente and Holub, 2013) [22] , responsible for severe economic losses worldwide (Rimmer et al., 2007) [14] . Xcc is mainly a seed born pathogen, but can alive in crop residues and cruciferous weeds and ornamentals (Roberts et al. 1999; Vicente et al. 2001; Lema et al. 2011) [15, 21, 10] . The crop may be affected at any stage during the growth period i.e., from the stage of young seedling till maturity. The bacterial cells infect cabbage through hydathodes at the leaf margins. In cabbage, typical V-shaped chlorotic lesions or through stomata, causing round lesions. Warm and humid condition favors the disease development and splashing water from rain or sprinkler spreads the pathogen from plant to plant. Xcc is also introduced primarily from infected seeds in the greenhouse or field. The bacterium can survive in the soil if infected plant residues are not decomposed. Since temperature generally remains low during the vegetative growth stage of crucifer plants, one would not always expect the diseased plant to be easily detected (Schaad, 1982) [18] . In favorable condition, black rot disease can reduce crop yield by more than 50 per cent (Williams, 1980) [23] . However, farmers in Tanzania have reported up to 100 per cent yield loss in cabbage (Massomo et al. 2004) [11] . Use of pathogen-free seeds, seed treatment, sound sanitation practices, including the elimination of potential inoculum sources, such as infected crop debris (Williams, 1980; Kocks et al., 1998) [23, 7] and weeds (Williams, 1980; Schaad and Dianese, 1981) [23, 17] and use of resistant cultivars and crop diversification and rotation are crucial methods for managing black rot (Williams, 1980) [23] . Kocks and Ruissen (1996) [8] showed that increased field resistance reduced the development of black rot in time and space in cabbage. Moreover, the use of resistant cultivars is one of the most sustainable options, in comparison with chemical products used to control various diseases (Rodrigues et al., 2004; Seabra et al., 2008) [16, 19] . Thus, the evaluation of the resistance of cabbage cultivars to black rot is very important for material recommendation and resistance source selection (Morais et al., 2012) [12] . Numerous studies have been carried out to identify new sources of resistance in crucifers against black rot. In cabbage, Bain (1952) [2] initially found resistance in the cv. ‘Huguenot’ and in the