Avaliação de genótipos diplóides AA de Musa spp. submetidos a estresse salino

Abstract

The salinity is a common factor of abiotic stress that seriously affects the agricultural production. Currently, over 800 million hectares worldwide are affected by salinity. One of the strategies to promote reincorporation of salinity areas and the productivity increase consists in development and selection of tolerant genotypes, which allows parental identification for crossings. The diploid (AA) of bananas Germplasm Bank's Active of the National Center for Research of Cassava and Fruticulture (CNPMF/Embrapa), sources of interest genes to improvement programmes, still are not characterized for their salinity tolerance. This research aimed to identify the salinity tolerance among nine banana diploid genotypes and characterize them genetically through ISSR and RAPD markers, to obtain cultivars adapted to saline soils. In physiological assessing, the growth variables analyzed were leaf area, plant height, diameterof pseudostem, leaves number, weight of fresh and dry matter. Twenty RAPD primers and twenty ISSR primers were used in molecular evaluation. The consensus dendrogram of similarity genetic analyses grouped the genotypes Monyet with Borneo, Buitenzorg with Tjau Lagada and 0323-03 with 0116-01, in ISSR and RAPD dendrogramas. The 0116-01 genotype showed greater salinity tolerance and could be used in future improvement programs. The 0337-02 genotype, presenting minor reduction in leaf area, number of leaves and fresh/dry biomass of limbo variables, was considered the most tolerant to salinity stress, while the Borneo genotype was the most sensitive on salt presence.