Chinese cabbage assessment reaction to black rot Xanthomonas campestris (Pammel) Dowson infection

Relevance. Chinese cabbage Brassica rapa subsp. pekinensis (Lour.) Hanelt is one of the most valuable vegetable crops of the cruciferous family Brassicaceae Burnett. The sphere of use for food purposes is quite large: it is consumed fresh, boiled, stewed, and salted. In terms of nutritional and medicinal properties it is not inferior to other brassicas crops, but even surpasses them. The main problems in its cultivation are diseases caused by fungal, bacterial and viral pathogens. Black rot (caus. agent Xanthomonas campestris pv. campestris (Pammel) Dowson) currently poses a serious threat. Under favorable conditions, the disease can lead to complete plant death and serious economic losses. In the conditions of greening of agriculture, the key method of protection is the creation of resistant cultivars and hybrids, which makes it relevant to search for resistance donors. The aim of the study: to identify sources of resistance in the Chinese cabbage collection of VIR using artificial infection with a set of races of black rot. Methods. Artificial infection with four races of black rot of 50 accessions of Chinese cabbage belonging to 16 cultivar types was carried out in the NPB «Pushkin and Pavlovsk laboratories of VIR» (St. Petersburg) in 2024-2025 according to the method of A. N. Ignatov. Each accession was grown in three replications 6 plant in replication and infected. Results. Three accessions of Chinese cabbage with complex high resistance to 4 races of black rot were identified. Cultivar types with high resistance and the geographical distribution of the degree of infection by each race were established. Conclusion. The determined accessions of Chinese cabbage can be involved in the breeding process aimed at creating cultivars and hybrids with complex resistance to black rot.