Agrupamento de cultivares de feijão em presença e em ausência de multicolinearidade

Filho, Alberto Cargnelutti; Storck, Lindolfo; Ribeiro, Nerinéia Dalfollo

doi:10.1590/s0103-84782009000900005

Cited by 6 publications

(4 citation statements)

References 4 publications

(4 reference statements)

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“…This allowed appropriate clustering. In studies on beans, Cargnelutti et al (2009) concluded that the presence of multicollinearity changed the clustering standards, and it was necessary to deal with the effects. The authors also mention that there are other forms of dealing with multicollinearity, such as using the Mahalanobis distance as dissimilarity measure.…”

Section: Resultsmentioning

confidence: 99%

Genetic divergence among cupuaçu accessions by multiscale bootstrap resampling

et al. 2015

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This study aimed at investigating the genetic divergence of eighteen accessions of cupuaçu trees based on fruit morphometric traits and comparing usual methods of cluster analysis with the proposed multiscale bootstrap resampling methodology. The data were obtained from an experiment conducted in Tomé-Açu city (PA, Brazil), arranged in a completely randomized design with eighteen cupuaçu accessions and 10 repetitions, from 2004 to 2011. Genetic parameters were estimated by restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) methodology. The predicted breeding values were used in the study on genetic divergence through Unweighted Pair Cluster Method with Arithmetic Mean (UPGMA) hierarchical clustering and Tocher's optimization method based on standardized Euclidean distance. Clustering consistency and optimal number of clusters in the UPGMA method were verified by the cophenetic correlation coefficient (CCC) and Mojena's criterion, respectively, besides the multiscale bootstrap resampling technique. The use of the clustering UPGMA method in situations with and without multiscale bootstrap resulted in four and five clusters, respectively, while the Tocher's method resulted in seven clusters. The multiscale bootstrap resampling technique proves to be efficient to assess the consistency of clustering in hierarchical methods and, consequently, the optimal number of clusters.

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Section: Resultsmentioning

confidence: 99%

Genetic divergence among cupuaçu accessions by multiscale bootstrap resampling

et al. 2015

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“…Thus, in genetic divergence studies, the criterion of choice of quantitative traits was the significance of treatment effects (lines) in analysis of variance (P ≤ 0.05) and a low multicollinearity between the selected response variables. Multicollinearity is defined as the degree to which any variable effect can be predicted or explained by other variables as a basic assumption of the cluster analysis, and can prevent erroneous analysis results, when duly exploited (Cargnelutti Filho et al, 2009). The end value of multicollinearity observed for these nine characteristics was considered low (72.64), validating the cluster analysis performed later (Cruz et al, 2011).…”

Section: Morphological Markersmentioning

confidence: 99%

Prediction of industrial tomato hybrids from agronomic traits and ISSR molecular markers

Figueiredo¹,

Resende²,

Faria³

et al. 2016

Genet. Mol. Res.

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ABSTRACT. Heterosis is a highly relevant phenomenon in plant breeding. This condition is usually established in hybrids derived from crosses of highly divergent parents. The success of a breeder in obtaining heterosis is directly related to the correct identification of genetically contrasting parents. Currently, the diallel cross is the most commonly used methodology to detect contrasting parents; however, it is a time-and cost-consuming procedure. Therefore, new tools capable of performing this task quickly and accurately are required. Thus, the purpose of this study was to estimate the genetic divergence in industrial tomato lines, based on agronomic traits, and to compare with estimates obtained using inter-simple sequence repeat (ISSR) molecular markers. The genetic divergence among 10 industrial tomato lines, based on nine morphological characters and 12 ISSR primers was analyzed. For data analysis, Pearson and Spearman correlation coefficients were calculated between the genetic dissimilarity measures estimated by Mahalanobis distance and Jaccard's coefficient of genetic dissimilarity from the heterosis estimates, combining ability, and means of important traits of industrial tomato. The ISSR markers efficiently detected contrasting parents for hybrid production in tomato. Parent RVTD-08 was indicated as the most divergent, both by molecular and morphological markers, that positively contributed to increased heterosis and by the specific combining ability in the crosses in which it participated. The genetic dissimilarity estimated by ISSR molecular markers aided the identification of the best hybrids of the experiment in terms of total fruit yield, pulp yield, and soluble solids content.

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“…For the condition of -0.6 MPa, three selection cycles were performed, with the discarded characteristics being G, MGT and RL, based on the weight of the weighting coefficients (2.273, 1.046 and 1.100) for the last canonical variable respectively (Table 4). Table 4 -Estimation of variances ( ), accumulated variances ( ac) and standardised weighting coefficients of the canonical variables for the characteristics, thousand seed weight (TW), mean germination time (MGT), primary root protrusion at nine days (G), normal seedlings (NS), primary root protrusion at five days (PL), length of hypocotyl (HL), length of root (RL), shoot dry weight (SDW) and root dry weight (RDW) for an osmotic potential of -0.6 MPa in a solution of NaCl The effect of multicollinearity on clustering in the bean hinders the true formation of groups (CARGNELUTTI FILHO et al, 2009), the effect being more expressive under salt stress (-0.3 and -0.6 MPa). Grouping of the bean genotypes by the Tocher optimisation method differed only under conditions of severe and weak multicollinearity.…”

Section: Resultsmentioning

confidence: 99%