Reaction of interspecific hybrids of Passiflora spp. to Xanthomonas axonopodis pv. passiflorae

Elisiane Fuhrmann Nilton Tadeu Vilela Junqueira Luiz Eduardo Bassay Blum Murilo Werneck Braga Graciele Bellon Keize Pereira Junqueira About the authors

The aim of this study was to evaluated the degree of resistance of 36 clones of passion obtained through mass selection progenies of seven interspecific hybrids, to three different isolates of X. axonopodis pv. passiflorae. The progenies were obtained by crossing among a commercial cultivate Passiflora edulis "yellow passion fruit" with wild species P. caerulea, P. edulis "purple passion fruit" and P. setacea. The bacterial isolates used were obtained in Rio Claro,SP, Planaltina,DF and Limeira,SP. Individual cloned were inoculated with bacterial solution in concentration with 108cfu ml-1 to 120 days of sowing. Symptoms were evaluated at 5, 10 and 15 days after inoculation, by measuring the longitudinal and transverse diameter of the lesion. Then, it was calculated the area under the lesion progress curve (AUPLC). A complete randomized block design with split plots was used, the treatments were the tested genotypes replicated in four blocks. All genotypes in each block had a three-plant plot. The bacterial isolates were inoculated in one plant of the plot, totaling three plants with different isolates. The plants of the genitors species P. caerulea (AUPLC=0.17) and P. setacea (AUPLC=14.50) presented high degree of resistance when compared to control plants BRS 'Gigante Amarelo' (AUPLC=4089.25), while hybrids genotypes presented intermediary values (AUPLC of 15.67 the 768.42), showing the importance of these wild Passiflora species as source of resistance to bacterial disease.

passion fruit; resistance; wild species; genotype selection; Passiflora caerulea; Passiflora setacea; interspecific hybridization

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