Extreme homogeneity among Brazilian wheat genotypes determined by RAPD markers

Abstract

-Random amplified polymorphic DNA markers (RAPD) were used to estimate the variability of 14 genotypes of Brazilian wheat (Triticum aestivum L.), using a set of 50 random 10-mer primers. A total of 256 reproducibly scorable DNA amplification products were obtained from 48 of the primers, 83% of which were polymorphic. Genetic distances among genotypes were calculated and a dendrogram and a principal coordinates analysis showing the genetic relationships among them were obtained. Despite the low variability found (average genetic distance of 27%), two groups of genotypes could be identified, which probably reflect how they were formed. Studies such as this one may be important in the planning and development of future improvement programs for this plant species.Index terms: Triticum aestivum, genetic variation, polymorphism, breeding methods. EXTREMA HOMOGENEIDADE ENTRE GENÓTIPOS BRASILEIROS DE TRIGO DETERMINADA POR MARCADORES DE "RAPD"RESUMO -Marcadores de RAPD (Random amplified polymorphic DNA) foram utilizados para estimar o grau de variabilidade genética entre 14 genótipos de trigo (Triticum aestivum L.) cultivados no Brasil, usando um conjunto de 50 "primers" aleatórios de 10 pares de bases (pb). Um total de 256 fragmentos de amplificação foram obtidos de 48 dos "primers" analisados. Destes, 83% eram polimórficos. Foram estimadas as distâncias genéticas entre os genótipos e a análise de um dendrograma e das coordenadas principais mostraram as relações genéticas entre eles. A despeito do baixo índice de variabilidade genética observado entre os genótipos (distância genética média de 27%), estes puderam ser reunidos em dois grupos, provavelmente relacionados à sua ancestralidade. Estudos como este podem ser importantes no planejamento e desenvolvimento de programas futuros para melhoramento desta espécie de planta.Termos para indexação: Triticum aestivum, variação genética, polimorfismo, métodos de melhoramento.

Estimation of Indian and Turkish Hexaploid Wheat Population Structure to be a Part of Improved Breeding Program

“…Although a number of advanced marker systems, both dominant and codominant as well as high throughput marker systems have developed, ISSR and RAPD have still maintained its credibility in wheat diversity studies due to some specific features like reliability and reproducibility of ISSR and cost-effectiveness of RAPD. Several workers have advocated RAPD and ISSR markers to estimate the genetic divergence in hexaploid wheat from different regions of the world (Bhutta et al, 2006;Cao et al, 1998;Du et al, 2002;Freitas et al, 2000;Hao et al, 2006, Khan et al, 2010Khavarinejad and Karimov, 2012;Malik et al, 2008;Maric et al, 2004;Mukhtar et al, 2002;Najaphy et al, 2011;Rehman et al, 2013).…”

Molecular Characterization of Hairy Fleabane Using Rapd

“…The observed similarity value is intermediary, compared with other weeds and crops. In Bidens spp., studies have determined an average similarity of 38% (VidaL et al, 2007) in populations from diferent sites, while for the wheat crops, the similarity was of 73%, which demonstrates a high homogeneity between the individuals (Freitas et al, 2000). Plants that propagate vegitatively present higher similarity, due to the lack of genetic recombination -such as in the Eichornia crassipes case (Cardoso et al, 2002).…”

Pathogenesis-related proteins in Brazilian wheat genotypes: protein induction and partial gene sequencing

“…These genotypes presented average genetic distance of 27% when random amplified polymorphic DNA markers (RAPD) were used to estimate their genetic variability (FREITAS et al, 2000).…”