Resistance to Brown Spot Disease (Alternaria alternata Tobacco Pathotype) in Three Tobacco Cultivars

1AgriBioInstitute, BG-1164 Sofia, Bulgaria
2Laboratory of Plant Pathology, Agricultural Faculty, Kobe University, Kobe, Japan


SLAVOV, S., S. MAYAMA and A. ATANASSOV, 2004. Resistance to brown spot disease (Alternaria alternata tobacco pathotype) in three tobacco cultivars. Bulg. J. Agric. Sci., 10: 7-14

Inheritance of tobacco resistance to brown spot disease was studied using tobacco cultivars Shiroenshu 1, Shiroenshu 601 and Beinhart 1000.1. Crosses between Shiroenshu 601 x Shiroenshu 1 and Beinhart 1000.1 x Shiroenshu 1 were done. Reversed crosses between those cultivars also were performed. F1 and F2 progenies were cultivated. Haploid plants from Shiroenshu 601, Shiroenshu 1 and F1 progenies of crosses Shiroenshu 601 x Shiroenshu 1 and Shiroenshu 1 x Shiroenshu 601 were obtained. All plants (parents, F1 and F2 progenies, and haploids) were tested for resistance to brown spot disease by artificial inoculation under laboratory conditions. Beinhart 1000.1 displayed resistant, Shiroenshu 601 were deemed moderately resistant and Shiroenshu 1 - susceptible to Alternaria alternata tobacco pathotype. Results showed that resistance of Beinhart 1000.1 is governed by a single factor and resistance of Shiroenshu 601 is most probably polygenic. It is suggested that maternal effects contribute to the resistance observed in Shiroenshu 601.

Key words: Nicotiana tabacum, Alternaria alternata, resistance, segregation