Desempenho agronômico de clones de bananeira 'Prata-Anã" em área com histórico do Mal-do-Panamá

Abstract

Panama disease, caused by the fungus Fusarium oxysporum f. sp. cubense, has assumed large importance in the North of Minas Gerais. In the irrigated perimeter from Jaiba there is presence of a supposedly tolerant material in which the disease was not established after 15 years of cultivation even in the presence of the pathogen. Thus, it was aimed to evaluate the genetic diversity, agronomic performance and behavior of clones of 'Prata-Ana' banana in the presence of Panama Disease. In an area of one hectare of 'Prata-Ana' banana explants were collected from the rhizomes and young leaves from twenty-four families, 11 were characterized in the moment of the collection as diseased being called (OPD 1, OPD 2, OPD 3, OPD 7, OPD 8, 9 OPD, OPD 10, OPD 11, OPD 12, OPD 14 and OPD 15), and apparently healthy 13 (OPS 16, OPS 17, OPS 18, OPS 19, OPS 20, OPS 21, OPS 22, OPS 23, OPS 24, OPS 25, OPS 27, OPS 28 and OPS 29) being OPD = origin of diseased plants and OPS = origin of healthy plants. The materials from which were obtained healthy clones of each family were taken to the micropropagation laboratory of the Universidade Estadual de Montes Claros Campus Janaúba. For analysis of genetic diversity, they were used 12 RAPD primers, 11 of them generated polymorphic bands, totaling 82 bands, 27 polymorphic (33%) and 55 monomorphic (67%). The average genetic distance was 43.5%. The genetic distances ranged from 11.8 to 85%. After cluster analysis, the clones were divided into eight groups, but he genotypes did not cluster according to the characteristic presence/absence of symptoms of the Panama disease. After acclimatization, the clones were taken for commercial property located in the irrigated perimeter from Jaiba being planted at a spacing of 4 x 2 x 1.7 m. The used irrigation system was micro sprinkler. The experimental design was in randomized blocks with 24 treatments (clones of Prata-Anā banana) being 20 plants per plot and six central useful plants, with three replicates. The evaluated characteristics were: pseudostem length, pseudostem diameter, leaf number, bunch mass, hands mass, e stem mass, number of hands and number of fingers, length and perimeter of the central fruit of the second hand, percentage of dead plants and incidence and severity of the Panama disease at the time of harvest. The individuals OPS 17, OPS 21 and OPS 23 were outstanding in two production cycles as tolerant to Panama disease. The individuals OPS 16, OPS 17, OPS 23 and OPS 27 show larger pseudostem diameters at ground level and at 30 cm from that as well plant height.