Molecular characterization of elephantgrass accessions through RAPD markers

Abstract

Elephantgrass pastures are limited by yield variations and reductions in forage quality and availability, thus making the search for genotypes with reduced seasonality a major concern. In order to verify the extent of genetic variability among contrasting cultivars, ten elephantgrass accessions were analyzed through DNA amplification by RAPD technique. A total of 160 DNA bands were generated with the use of 44 random primers and 23% of these bands were monomorphic for all accessions. Gel-obtained binary data (1 for presence and 0 for absence) were used for generating a genetic distance matrix, which was utilized in a UPGMA grouping analysis. Elephantgrass cultivars Cameroon and Vruckwona were the accessions mostly divergent from the others, with an average genetic distance of 0.34. The accessions with the lowest average genetic distances from the others were Pioneiro and CNPGL 27-5, both with a distance of 0.25. Overall, genetic distances ranged from 0.06 to 0.43, indicating little genetic variability for the set of accessions, despite the contrasting morphology of the studied genotypes.Index terms: molecular markers, elephantgrass, RAPD, DNA. RESUMOO cultivo do capim-elefante é limitado por variações na produção de biomassa e por reduções na qualidade e disponibilidade de forragem, tornando prioritária a busca de genótipos com menor sazonalidade de produção. Para verificar a extensão da variabilidade genética entre cultivares contrastantes, 10 acessos foram analisados via amplificação do DNA pela técnica RAPD. Foram utilizados 44 primers aleatórios, que produziram um total de 160 bandas de DNA, sendo que 23% das bandas analisadas foram monomórficas para todos os acessos. Os dados binários, originados dos géis (1-presença, 0-ausência), foram utilizados para gerar uma matriz de distâncias genéticas, que foi utilizada para uma análise de agrupamento segundo o método da média das distâncias (UPGMA). Os acessos mais divergentes dos demais foram Cameroon e Vruckwona, com distâncias genéticas médias de 0,34. Os acessos com menores distâncias genéticas médias dos demais foram Pioneiro e CNPGL 27-5, ambos com uma distância genética média de 0,25. As distâncias genéticas, considerando todas as análises, variaram de 0,06 a 0,43, indicando uma variabilidade genética pouco acentuada, embora os acessos estudados sejam bastante contrastantes em relação à morfologia e fisiologia. Termos para indexação:Marcadores moleculares, Capim-Elefante, RAPD, DNA.

Research Article Diversity among elephant grass genotypes using Bayesian multi-trait model.

“…This fact is confirmed by observing the mean values of the evaluated traits, where Mercker 86-Mexico obtained high means for the agronomic traits %DM and DWM, while Mercker Pinda México presented higher means for the industrial traits %CEL and %ADF. These results differ from those found in the literature, where a classification of the elephant grass germplasm variability is reported in four morphological groups: Napier, Merker, Cameroon, Anão, and interspecific hybrids (Pereira, 1992), or a division considering clustering results based on molecular analysis with the formation of two groups, where group I is constituted by morphologically closer accesses from the cultivars Napier and Merker, while group II presents greater morphological identification with the cultivar Cameroon (Passos et al, 2005;Pereira et al, 2008). From the results obtained in this study, the genotypes Mercker Pinda Mexico and Mexico-86 Mercker do not belong to the same group where Napier's access based on the biomass quality and morpho-agronomic traits have been allocated.…”

“…Currently, some research has been conducted to estimate the diversity among elephant grass genotypes based on morphological and agronomic (Shimoya et al, 2001;Shimoya et al, 2002;Rocha et al, 2017), cytogenetics (Techio et al, 2002) and molecular traits (Daher et al, 2002;Passos et al, 2005;Pereira et al, 2008;Azevedo et al, 2012;Wanjala et al, 2013). However, studies on genetic diversity in elephant grass for bioenergy purposes based on biomass quality are scarce in the literature.…”

Diversidade genética entre acessos de capim-elefante obtida com marcadores moleculares

“…Considerando-se a distância genética relativa de 0,80, os acessos estudados neste trabalho podem ser divididos em dois grandes grupos. Resultado semelhante também foi encontrado por Passos et al (2005), que utilizaram marcadores RAPD para avaliar a diversidade genética entre dez acessos de capim-elefante. O Grupo 3, formado pelo acesso Kizozi, destacou-se pela posição isolada no dendrograma, demonstrando ser um material genético muito diverso dos demais acessos avaliados.…”

Research Article Prediction of genetic gains by selection indices using mixed models in elephant grass for energy purposes.

“…Manual crossings were performed according to Silva et al (2014), pollen grains of elephant grass genotypes (male genitor) were collected in paper bags and then brought to female genotypes when their inflorescences, duly protected with a paper bag, had receptive stigmas. Emasculate process was not needed because of protogyny (Passos et al, 2005). The crossing was carried out between 8:00 and 10:00 am in 2013.…”