Divergência genética em genótipos de feijão comum cultivados em Mato Grosso do Sul

Abstract

Genetic divergence in common bean genotypes grown in the State of Mato Grosso do SulThe common bean breeding is based, mainly on the hybridization of cultivars and lines, so it is important to know the dissimilarity among the parents to obtain superior genotypes. The objectives of this work were: to cluster the genotypes by multivariate techniques using hierarchical method (nearest neighbor) and the canonical variables; to point the relative contribution of the analyzed traits for genetic dissimilarity and to point out the most promising hybrid combinations to produce superior recombination using as dissimilarity measure the square of the Euclidean distance. Thus, thirteen bean genotypes (Phaseolus vulgaris L.), involving commercial varieties and advanced lines, were assessed at the experimental Campus at the Universidade Estadual de Mato Grosso do Sul -UEMS, in Aquidauana, Mato Grosso do Sul State, Brazil. The experiment was carried out in a randomized complete block design with three replications in the "dry" crop season, in the period 2005/2006. There were assessed the following traits: number of pods per plant (POD), number of seeds per pod (SEED), mass of 100 seeds (MHS) and grain yield (YD). The beans O melhoramento do feijoeiro (Phaseolus vulgaris L.) baseia-se, principalmente, na hibridação de cultivares e linhagens, sendo importante o conhecimento da dissimilaridade entre os genitores para a obtenção de genótipos superiores. Este trabalho teve por objetivo promover o agrupamento de genótipos de feijoeiro comum, entre cultivares e linhagens, em função da dissimilaridade genética apresentada, indicar a contribuição relativa dos caracteres avaliados para a dissimilaridade genética e apontar as combinações híbridas mais promissoras para produzir recombinações superiores, utilizando-se de procedimentos multivariados. Desta forma, 13 genótipos de feijão comum, entre cultivares e linhagens avançadas, foram avaliados no ano agrícola 2005/2006, no período da "seca", na área experimental da Universidade Estadual do Mato Grosso do Sul, em Aquidauana. O experimento foi conduzido no delineamento de blocos casualizados, com três repetições, avaliando-se os caracteres: número de vagens por planta (NVP), número de grãos por vagem (NGV), massa de 100 grãos (MCG) e produtividade de grãos (PROD). Os genótipos foram reunidos em três grupos pelo método hierárquico do vizinho mais próximo e em cinco grupos pelas variáveis canônicas. O cultivar IAC Carioca Eté mostrou-se o mais dissimilar, podendo ser estrategicamente utilizado em hibridações artificiais dirigidas. O caráter "MCG" apresentou a maior contribuição relativa para a dissimilaridade genética total e as associações mais divergentes foram: "CNFv 8025 x IAC Carioca-Eté", "Rudá x IAC Carioca-Eté" e "CNF 7135 Bambuí x IAC Carioca-Eté". Palavras-chave:Phaseolus vulgaris, análise multivariada, variabilidade genética.

Morphoagronomic characterization and genetic diversity of a common bean RIL mapping population derived from the cross Rudá x AND 277

“…As in the present study, an evaluation of 13 genotypes (advanced lines and commercial cultivars) also detected that M100 was the trait that most contributed to the genetic dissimilarity in the common bean (Corrêa and Gonçalves, 2012). Similarly, Benin et al (2002) reported that the mass of thousand beans was the most important trait for the genetic dissimilarity in bean plant genotypes.…”

Genetic divergence in the common bean (Phaseolus vulgaris L.) in the Cerrado-Pantanal ecotone

“…Similar genotypes are not recommended for use in genetic breeding programs by hybridization, because the genetic variability of segregating populations should not be restricted (Correa and Gonçalves, 2012); genetically similar parents tend to share many genes or alleles, and their crossing results in a low level of allelic heterozygosity (Cruz et al, 2014). The most divergent pair according to the Euclidian distance was 'Ametista' (1) and 'CNFC 10762' (10) (D = 2.00), while according to the Mahalanobis distance, it was 'BRS Esplendor' (3) and 'CNFC 10762' (10) (D 2 = 690.10).…”

“…The crop is highly susceptible to biotic and abiotic stressors, its architecture is inappropriate for mechanical harvesting, and its productivity and grain quality need improving . When starting a genetic breeding program, one of the most crucial aspects is the choice of parents (Correa and Gonçalves, 2012). Genetic divergence between individuals or populations is important in breeding programs that involve hybridization, because it facilitates the identification of parents that produce heterotic progeny and results in a higher probability of obtaining superior genotypes in segregating generations (Vidigal et al, 1997;Bertan et al, 2003;Benitez et al, 2011).…”

“…Falconer and Mackay (1996) stated that hybrid heterosis is caused by dominance effects of the trait involved and the square of the difference in allele frequencies with their parents, in addition to the epistatic effects that are usually neglected. Genetic divergence in the common bean has been estimated by Coelho et al (2007), Gonçalves (2012), andGonçalves et al (2014).…”

Genetic Divergence Among Cotton Genotypes Grown in the Main Season and Off Season

“…The use of agronomic characters and multivariate techniques is common for plant breeding of different crops, such as maize (MORO; SILVEIRA; CARGNELUTTI FILHO, 2007, CARDOSO et al, 2009SIMON;KAMADA;MOITEIRO, 2012;MIRANDA, 2003), common bean (ELIAS et al, 2007;BARELLI et al, 2009;CORREA;GONÇALVES, 2012), castor bean (RODRIGUES et al, 2010) and cassava (ZUIN et al, 2009). According to Hallauer and Miranda Filho (1981), in addition to the high genetic divergence, the plant performance related to the desired characteristics in the desired environment is greatly important for choose the plant parents, in order to successfully obtaining superior lines.…”