Estudo citogenético e molecular em nove espécies do gênero Solanum L. (Solanaceae A. Juss)

Abstract

Mitotic chromosomes of nine Solanum L. (Solanaceae A.Juss.) species were cytogenetically analyzed using the conventional technique, CMA/DAPI and florescent in situ hybridization. S. atropurpureum Schrank, Solanum dulcamara L., S. gilo L., S. melongena L. and S. nitidibaccatum Bitter., showed a diploid chromosome number 2n=24. While Solanum luteum Mill., S. nigrum L., and S. laciniatum Ait., showed 2n=48, 2n=72, 2n=92, respectively.The species karyotype were symmetric, with morphology metacentric or submetacentric and the interphasic nucleus were semi-reticulated type. The condensation pattern was always from the telomere to the centromere. S. luteum showed heteropcnotic chromosomes pair in metaphases. S. dulcamara, S. atropurpureum and S. luteum, two CMA3 +/DAPI- terminals blocks were observed in one chromosome pair. Solanum nitidibaccatum showed two subdivided satellites with the application of fluorochromes. We also observed in this species in several CMA3 +/DAPI- blocks in telomeres. In Solanum laciniatum and S. nigrum were observed four CMA3 +/DAPI- blocks in two chromosome pair. The application of DNAr 45S probes in the FISH technique was applied only in S .luteum, S. nigrum, and in S. laciniatum, and showed two hybridization sites of rDNA 45S in the fist one, and four sites in the others. We noticed that the localization of species-specific marker was successful, allowing the identification of the analyzed species. The estimation of the genetic diversity in Solanum species was also made using ISSR markers. A total of 27 primers were tested giving 299 polymorphic bands with a average of 97,4%. However the intra-specific average was lower 16,7%. We realized that the application of just one UBC 841 or 846 primer can be used to identify the genotypes of S. melongena safely. The dendrogam gendered by UPGMA method grouped the species analyzed in four groups.