Short Communication Comparison of methods for estimates of molecular genetic diversity in genus Croton: influence of coefficients, clustering strategies and data projection

Abstract

ABSTRACT. We investigated 10 similarity (and disimilarity) coefficients in a set of 40 wild genotypes of Croton linearifolius subjected to analyses using hierarchical grouping methods, grouping methods by optimization and data projection in two-dimensional space. Genotypes were characterized by analyzing DNA polymorphism with the use of 15 ISSR and 12 RAPD markers. The distance measurements were compared by the Spearman correlation test, projection in twodimensional space and grouping efficiency evaluation. The Spearman correlation coefficients between the 10 coefficients evaluated were 5567 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (3): 5566-5573 (2014) Comparison of coefficients in Croton with molecular markers significant (P < 0.001) and indicated significant changes in genotype ranking due to type of coefficient used (0.76 ≤ r s ≤ 1). Wide variation was also observed in the efficiency of clustering methods, where the unweighted pair group method with arithmetic mean was the most suitable (0.3 ≤ D ≤ 1.5 ; 0.41 ≤ r c ≤ 0.77; 5.99 ≤ S ≤ 12.61). Projection efficiencies in two-dimensional space showed high-stress values (65 < S < 89%). Similar to the results observed for hierarchical clustering methods and for projection in two-dimensional space, the formation of groups with grouping methods by optimization showed variations when using different coefficients. We believe that the results confirm the influence of coefficients in studies of genetic diversity, showing the need to use criteria and standards for selecting appropriate methods for genetic studies of the genus Croton.

Genetic diversity of native populations of Croton tetradenius Baill. using ISSR markers

“…Several studies on genetic diversity in medicinal plants have been carried out using ISSR molecular markers, such as those in Croton (Lira Neto, 2011;Scaldaferri et al, 2014;Rocha et al, 2016), in Varronia curassavica Jacq. (Brito et al, 2016), in Capparis spinosa L. (Liu et al, 2015), in Rheum (Tabin et al, 2016), in Withania somnifera (Khan and Shah, 2016), and in Panax stipuleanatus Tsai (Trieu et al, 2016).…”

Caracterização e seleção de marcadores moleculares em Croton linearifolius Mull. Arg. como subsídio para estudos genéticos

“…O sucesso na seleção das 14 combinações de iniciadores RGA e dos 16 iniciadores ISSR, tendo por critérios a resolução das marcas e os padrões polimórficos atesta que os marcadores RGA e ISSR são potencialmente úteis para subsidiar estimativas genéticas para Croton linearifolius. Os iniciadores selecionados, em conjunto com os métodos de estimativa de diversidade previamente caracterizados por Scaldaferri et al (2014) deverão potencializar a obtenção de informações populacionais associadas a diversidade e estrutura genética em populações naturais de C. linearifolius.…”

Transferability of microsatellite loci from Croton floribundus Spreng. to Croton urucurana Baill. (Euphorbiaceae)

“…Because of this great medicinal importance, genetic studies are essential to develop conservation strategies and also products (Alves et al, 2012). For Croton genus there are some research related to genetic diversity (Angelo et al, 2005;Silvestrini et al, 2015;Rinthong et al, 2011;Scaldaferri, 2013Scaldaferri, , 2014Oliveira et al, 2016;Almeida-Pereira et al, 2017;Silva et al, 2018), however, molecular information are still scarce; for species C. urucurana they are almost non-existent and it is necessary to advance in the genetic diversity characterization of this species.…”