GENETIC SIMILARITY AMONG ACCESSIONS OF GUAVA AND BRAZILIAN GUAVA ARACAZEIROS BASED ON AFLP MARKERS

Species of the genus Psidium, like guava and Brazilian guava trees, are economically important and have the area of primary genetic diversity in Brazil. It was determined the genetic relationships based on AFLP marker for accessions of Psidium Germplasm Bank (PGB) of Embrapa Semiarid to guide improvements and management of genetic resources of the genus. Eighty-eight accessions were analyzed, 64 of guava and 24 of Brazilian guava, collected in ten Brazilian States, adopting for the cluster dendrogram UPGMA, considering the similarity matrix of Jaccard's coefficient of 149 polymorphic AFLP bands from 16 combinations of primers EcoRI and MseI. Analysis of variance of molecular data was performed considering the variation between and within populations of guava from the ten states. The dendrogram showed good definition, with cophenetic coefficient of 0.94. Two major groups were identified: one formed by accessions of guava and other with access to Brazilian guava, including some accessions of guava. Specific groups were observed in the dendrogram only for individuals guava collected in Goias and Roraima. These accessions showed similarity ranging from 28 to 98%, suggesting a high genetic variability of them. The variation among accessions was estimated at 0.16 (phi(ST)), indicating moderate genetic differentiation among guava populations from the ten states. To increase the genetic variability of the ABG studied, it is suggested to collect more hits in the states of Goias and Roraima, due to the high degree of similarity among accessions from these states, as well as extensive collections in other Brazilian states. Crosses among the few accessions of guava which are positioned in the group of Brazilian guava were also suggested for the development of interspecific hybrids in the genus Psidium.