Reação fenotípica de genótipos de abóboras ao vírus da mancha anelar do mamoeiro, estirpe melancia (Pappaya ringspot virus, strain watermelon – PRSV-W)

Abstract

The Pappaya ringspot virus, watermelon strain - PRSV-W is the most important viral disease of Cucurbita spp. in the tropical conditions. The study evaluated the phenotypic resistance and the pattern of symptoms presented by the genotypes of Cucurbita spp. to PRSV-W. The experiment was conducted in completely randomized design with four replications. The plants were evaluated for symptoms 30 days after inoculation, using a scale where: Note - 1: plants with no symptoms of mosaic and; note - 5: plants with leaves showing mosaic intense with blistering and the presence of more severe leaf deformation. Nine genotypes were evaluated, three landraces [ABTO#01; ABTO#02 (C. maxima) e ABTO#03 (C. moschata) and six commercial cultivars [cv.Caserta (C. pepo); cvs. Menina Brasileira; Paulista; Baianinha; Jacarezinho (C. moschata) and the interspecific hybrid Tetsukabuto or Kabutiá (C. moschata x C. maximum)]. Inbred progenies from ABTO#01 were also evaluated. All commercial genotypes were susceptible and symptoms were blistering, mosaics, leaf narrowing and underdevelopment. The genotype ABTO#01 and their inbred progeny presented no virus symptoms during the evaluation period, being considered resistant and a promising genotype to be used in breeding programs of the Cucurbita spp. aiming resistance to PRSV-W.