GENETIC DIVERSITY IN ACCESSIONS OF Stylosanthes spp. USING MORPHOAGRONOMIC DESCRIPTORS

Abstract

-The great diversity of plants in the Brazilian Semiarid environment represents a vital natural resource for the human populations of these areas. Many of these plants have been subject to extractivism and among these, the species of the genus Stylosanthes, which have occurrence in this region, show great potential, however, studies on this topic are limited, and little is known about the existing variability among these plants. Therefore, further study is necessary, to facilitate the development of cultivars. This might reduce the scarcity of fodder supply in this region, but to commence a plant breeding programme, it is essential to identify genetic variability. Therefore, this study evaluated 25 accessions of Stylosanthes spp., to identify the most suitable candidates to be parents in a plant breeding programme for the semiarid region of the state of Bahia. Two experiments were carried out in different sites in an experimental design of randomized blocks with four replicates, with a spacing of 3.0 × 8.0 m. A large amount of genetic diversity was observed among accessions and the genotypes BGF 08-007, BGF 08-016, BGF 08-015 and BGF 08-021 were the most divergent in the overall evaluation. For the structuring of segregating populations, it is recommended to combine the genotypes BGF 08-016, BGF 08-015, BGF 08-007 and BGF 08-006, and for the interspecific crosses, a hybrid from the accession BGF-024 with the accessions BGF 08-016 or BGF 08-015. This might generate superior individuals for mass descriptors, which are the most important for animal forage breeding.Keywords: Semiarid. Native forage. Morphological descriptors. DIVERSIDADE GENÉTICA EM ACESSOS DE Stylosanthes spp. UTILIZANDO DESCRITORES MORFOAGRONÔMICOSRESUMO -A grande diversidade de plantas do Semiárido representa um recurso natural vital para as populações humanas dessa região. Muitas dessas plantas são exploradas de forma extrativista e entre elas, as espécies do gênero Stylosanthes, que são nativas tem grande potencial, porém, os trabalhos realizados têm sido modestos e pouco se conhece a respeito da variabilidade existente nessas plantas. Por isso, esforços devem ser priorizados no sentido de estudá-las, o que certamente poderá ajudar a criar formas para o desenvolvimento de cultivares e, assim, amenizar a escassez de forragem nessa região. Entretanto, para iniciar trabalhos de melhoramento, primeiro deve-se buscar variabilidade genética. Assim, este trabalho avaliou 25 acessos de Stylosanthes spp., a fim de identificar os melhores para serem genitores no programa de melhoramento genético para o Semiárido baiano. Para isso, foram conduzidos dois experimentos em diferentes locais no delineamento blocos casualizados completos com quatro repetições num espaçamento 3,0 × 0,8 m. Foi constatada grande diversidade genética entre os acessos, sendo que os genótipos BGF 08-007, BGF 08-016, BGF 08-015 e BGF 08-021, mostraram-se como os mais divergentes na avaliação geral. Para a formação de populações segregantes, recomenda-se combinar os genótipos ...

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Genetic diversity in natural populations of Stylosanthes scabra using ISSR markers

“…There are twenty-five species of Stylosanthes in Brazil and thirteen of them are found only in national territory (Santos-Garcia et al, 2011). S. scabra is a species with a large occurrence in South America (Calles and Schultze-Kraft, 2016), and this species is more common in the Brazilian Northeast, occurring in different environmental conditions (Oliveira et al, 2016). In other states from Brazil, this species occurs in Goiás, Minas Gerais, São Paulo (Brandão and Costa, 1979), Mato Grosso and Mato Grosso do Sul (Costa et al, 2008).…”

Research Article Genetic diversity in natural populations of <i>Stylosanthes</i> <i>scabra</i> Fabaceae using ISSR markers

“…There are 25 species of Stylosanthes in Brazil, of which 13 are endemic (Santos Garcia et al, 2011). Stylosanthes scabra is a species with widespread occurrence in Brazil's Northeast (Calles and Schultze Kraft, 2016) and can grown in low fertility soils, particularly low phosphorus content, conferring an advantage over other species (Gonzalez et al, 2000;Oliveira et al, 2016). Although S. scabra populations occur in various environments in Brazil, genetic studies at the DNA level have not been performed (Queiroz et al, 2001).…”