Genetic diversity assessed by microsatellite markers in the amphicarpic species Trifolium polymorphum Poir.

ABSTRACT Trifolium polymorphum Poir. is an amphicarpic forage legume from southern Brazil, Uruguay, Argentina, Paraguay and Chile. Information on the genetic diversity of natural populations in natural grasslands in southern Brazil is limited. In order to increase the knowledge about this species, an analysis of the genetic diversity was carried out in 10 natural populations of T. polymorphum with the use of 20 microsatellite markers. The expected heterozygosity in T. polymorphum populations ranged from 0.40 to 0.43, with a mean of 0.42. A total of 193 alleles were detected with a mean of 9.3 alleles per locus and polymorphic information content (PIC) for these markers of 0.62 to 0.89 with a mean of 0.84.The grouping based on the Jaccard’s coefficient of similarity classified populations, regardless of their regions of origin, into two groups with a mean similarity coefficient of 0.32, reflecting the high genetic variability of the populations, especially those located in the Campanha phytogeographic region. This information on diversity can be used to plan future germplasm collection strategies for conservation purposes and also for the breeding of the species

Caracterização morfológica e dissimilaridade genética entre variedades crioulas de melão Morphological characterization and genetic dissimilarity in melon landraces

Variedades crioulas de melão (Cucumis melo) são cultivadas no Sul do Brasil para consumo familiar e também para comercialização dos frutos. No entanto, existe uma carência de trabalhos relativos a sua caracterização. Este trabalho teve por objetivo caracterizar e avaliar a variabilidade genética de variedades crioulas de melão do Sul do Brasil mantidos no Banco Ativo de Germoplasma de Cucurbitáceas da Embrapa Clima Temperado. Foram caracterizados 14 acessos utilizando 26 descritores morfológicos de fruto. Os dados foram analisados pelos métodos de agrupamento de Tocher e hierárquico UPGMA. Os métodos de agrupamento foram parcialmente concordantes. O acesso C88 possui características distintas, ficando isolado dos demais, pois é o único entre todos os avaliados que apresenta formato piriforme e sem gomos, cor de epicarpo creme, cor de polpa branca e ruptura profunda no fruto. Existe grande variabilidade genética, para caracteres de frutos, nas variedades crioulas de melão conservadas nesse Banco Ativo de Germoplasma, com potencial para uso no melhoramento genético, destacando-se o acesso C71 por possuir sabor adocicado e polpa de cor laranja e o C72, por apresentar elevados valores de peso de fruto e espessura de polpa.<br>Melon landraces (Cucumis melo) are cultivated in South of Brazil for family consumption and also for marketing fruits. However, there is a lack of works related to characterization of these landraces. The objective of this work was to characterize and evaluate genetic variability of melon landraces from South of Brazil which are maintained in the Cucurbitaceae Genebank at Embrapa Clima Temperado, trough morphological characterization. Fourteen accessions were characterized in 26 morphological fruit descriptors. Data were analyzed by Tocher grouping method and UPGMA hierarchical. The two methods agreed partially. The accession C88 has unique characteristics, being isolated when compared to the other accessions, it is the only one among all evaluated with pyriform shape and fruit ribs absent, cream skin color, white flesh color and deep groove in the fruit. There is great genetic variability for fruit traits in the melon landraces from South of Brazil maintained in this Gene Bank, with potential use in plant breeding, with an emphasis on the accession C71 due to its sweet taste and orange pulp and the C72 due to its high values for fruit weight and flesh thickness