Resistencia de nuevos híbridos de tabaco (Nicotiana tabacum L.) derivados del cultivar Beinhart-1000-1 frente a Phytophthora nicotianae Breda de Haan.

The objective of the work was to evaluate the resistance of new tobacco (Nicotiana tabacum L.) hybrids to Phytophthora nicotianae Breda de Haan by incorporating resistance genes from 'Beinhart-1000-1'. Two hundred plants per genotype were included in seedbed experiments, where a randomized block design with three replicates was used. The percentage of plants affected by the disease was evaluated until the susceptible control 'KY-14' reached 100% of diseased plants. For the plantation experiment, 45 day old plants were transplanted from another developed seedbed, and a completely randomized design with two replications was used. Each cultivar occupied a plot with five furrows of 20 plants each. The data on the percentage of diseased plants in both experiments allowed determining the Area Under the Disease Progress Curve (AUDPC) to subsequently perform a Simple Ranked Analysis of Variance, Fixed Effects Model. The AUDPC values were higher (less resistant) at the seedling stage than at the planting stage in both experiments, and it was observed that the hybrids and 'Beinhart-1000-1' showed the lowest AUDPCvalues in the two years of research. The female parents achieved higher AUDPC values (less resistant) and differed from their respective F1 offspring. All five tobacco hybrids showed high levels of resistance to P. nicotianae, exceeding the resistance of the female parents, but not that of the male parent 'B-1000-1'. [ABSTRACT FROM AUTHOR]