Evaluación de la resistencia de cuatro variedades de brócoli a Plasmodiaphora brassicae Woronin

Abstract

This research aims to: evaluate the resistance of four varieties of broccoli (avenger, Legacy, Coronado, SK6) to Plasmidiophora brassicae Woronin in the province of Chimborazo to develop in the future of efficient management alternatives. A completely randomized design was used with eight treatments and eight repetitions, Treatment 1 Avenger inoculum, treatment 2 Legacy inoculum, treatment 3 Coronado inoculum, treatment 4 SK6 inoculum, treatment 5 Avenger without inoculum, treatment 6 Legacy without inoculum, treatment 7 Coronado without inoculum and treatment 8 SK6 without inoculum, at 25 days after sowing the inoculum was performed with the pathogen Plasmodiophora brassicacea, Woronin. The same ones that were transplanted into polyethylene bags, the development of the disease was evaluated every 20 days after transplantation using a scale proposed by Hourichi and Hori, as amended by Strelkov where the rate of the disease was calculated in percentage and corresponded to the presence of hernias in the roots, also the pH of the both soil and root were evaluated. Treatments without inoculum had an index of 0% disease, treatments with inoculum: Avenger, Legacy and Coronado had different percentage rate of disease in different data collections, being greater than 100 days after the inoculum: 42,57%; 51,84%; 46,97%, respectively, presenting hernias in more than two thirds of the roots, treatment SK6 with inoculum presented an index of 0% throughout the test indicating the absence of symptoms, it means hernias, the pH was maintained at neutral values throughout the test so that was not the optimal but it was not a limiting factor for the development of the disease by the results, it is concluded that the SK6 variety is resistant to the pathogen Plasmodiophora brassicae, Woronin. Keywords: broccoli varieties, genetic modification, severity, illness index.