Platonia insignis Mart. (Clusiaceae) is widespread throughout the Amazon and adjacent areas. The fruits (known locally as "bacuri") have significant commercial potential, but the species is under threat from agro-industrial expansion. The genetic variability within 72 genotypes of P. insignis belonging to ten populations collected in the Brazilian states of Maranhão and Piauí, and maintained in the germplasm collection of Embrapa Meio-Norte, has been determined, and the organization of genetic diversity within populations, between populations and among geographic groups verified. Eighteen selected inter simple sequence repeat primers allowed amplification of 236 loci of which 221 (93.64%) were polymorphic, indicating a high level of genetic diversity. At the population level, the Shannon and Nei diversity indices ranged from 0.082 to 0.323 and from 0.120 to 0.480, respectively. The global coefficient of genetic differentiation (G(ST)) was 0.4730 indicating that differentiation between populations was significant, a finding that was confirmed by analysis of molecular variance (Φ(ST) = 0.28). UPGMA cluster analysis revealed that the genotypes could be stratified into groups that were well defined and consistent with those identified in the dendrogram constructed using pair wise Φ(ST) values. The high genetic diversity established in this study may facilitate the management and conservation of the germplasm of P. insignis.

ABSTRACT. We evaluated genetic variability of mango (Mangifera indica) accessions maintained in the Active Germplasm Bank of Embrapa Meio-Norte in Teresina, Piauí, Brazil, using RAPDs. Among these accessions, 35 originated from plantings in Brazil, six from the USA and one from India. Genomic DNA, extracted from leaf material using a commercial purification kit, was subjected to PCR with the primers A01, A09, G03, G10, N05, and M16. Fifty-five polymorphic loci were identified, with mean of 9.16 ± 3.31 bands per primer and 100% polymorphism. Application of unweighted pair group method using arithmetic average cluster analysis demonstrated five genotypic groups among the accessions examined. The genotypes Rosa 41, Rosa 48 and Rosa 49 were highly similar (94% similarity), whereas genotypes Sensation and Rosa 18 were the most divergent (only 7% similarity). The mango accessions were found to have considerable genetic variability, RAPD analysis of the genetic diversity of mango germplasm demonstrating the importance of analyzing each genotype in a collection in order to efficiently maintain the germplasm collection.

We described the isolation and characterization of 23 microsatellite loci from the stingless bee (Melipona subnitida). Out of 52 microsatellite primer pairs screened, 17 loci displayed polymorphism and 6 were monomorphic. The analysis of variability was performed in 56 individuals. The number of alleles per locus ranged from 2 to 22 among populations; values for expected and observed heterozygosities ranged from 0.125 to 1.000 and from 0.121 to 0.923, respectively. These are the first microsatellite markers characterized for M. subnitida and they will be useful in obtaining estimates of population-level genetic diversity studies in a near future.

The objective of this study was to characterize sixteen genotypes of P. insignis available in the Embrapa Meio-Norte germplasm collection (Teresina, Piauí, Brazil) with respect to 33 morphological traits relating to leaves, flowers, branches, fruits and seeds. Phenotypic variance among genotypes was estimated using the Mahalanobis distance technique and the unweighted pair group method with arithmetic mean analysis (UPGMA). The method of Singh (1981) was used to determine which of the traits contributed most to diversity within genotypes. The occurrence of phenotypic variability among P. insignis genotypes indicated that it would be possible to achieve positive gains with selection. The most distant genotypes were BGB 16 and BGB 48, while crosses between genotype BGB 48 and genotypes BGB 32 and BGB 56 offers the greatest potential as parental types for this fruit tree breeding programs . The flesh content, ovary and fruit length , ratio between fruit length and diameter were the characters that most contributed to diversity among the studied genotypes. Keywords: phenotypic diversity, Platonia insignis, Mahalanobis distanceAnálise multivariada da morfologia reprodutiva e vegetativa do bacurizeiro Resumo O objetivo do trabalho foi caracterizar dezesseis genótipos de bacurizeiro disponível na Coleção de Germoplasma da Embrapa Meio-Norte (Teresina, Piauí, Brasil) com base em 33 caracteres relacionados à folha, flor, ramos, fruto e semente. A divergência fenotípica entre os genótipos foi estimada pela distância de Mahalanobis e a análise de agrupamento dos genótipos por meio do método hierárquico da ligação média não ponderada (UPGMA). O método de Singh foi utilizado na determinação de quais caracteres mais contribuem para a diversidade dos genótipos. Observou-se diversidade fenotípica significativa entre os genótipos estudados, indicando que é possível obter ganhos genéticos importantes por meio da seleção. Os genótipos BGB 16 e BGB 48 são os mais divergentes. Entretanto, cruzamentos entre o genótipo 48 e os genótipos BGB 32 e BGB 56 oferecem potencial como parentais em programas de melhoramento da frutífera. O teor de polpa, comprimento do fruto, comprimento do ovário e relação comprimento / diâmetro do fruto são os caracteres que mais contribuem para a diversidade entre os genótipos estudados.Palavras-chave: diversidade fenotípica, Distância de Mahalanobis, Platonia insignis

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