Repeatability and genetic dissimilarity using biometric traits of black wattle seeds.

• Autor(a) principal: FLÔRES JUNIOR, P. C.
• Data de Publicação: 2018
• Outros Autores: IKEDA, A. C., SCHUHLI, G. S. e, SILVA, L. D., HIGA, A. R.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1093520
• topic: Black wattle; Number of measurements; Coeficiente de repetibilidade; Acácia Mearnsii; Principal component analysis; Repeatability

Selecting superior individuals requires a careful genetic evaluation. For this reason, repeated measurements of biometric traits need to be carried out in the same individual. This index is a strategic tool aimed to assist in providing accurate observations and further selection. The objectives of this study were to estimate the repeatability coefficient in many seed traits for black wattle clones; test the best method to estimate the optimal number of measurements required; and to analyze genetic dissimilarity. Seed weight, longitudinal length, transversal length, thickness and hilum size were evaluated in nine clones measuring 50 seeds per clone The following methods were employed in the evaluation: analysis of variance, principal component analysis (PCA) based on the correlation and covariance matrices, and structural analysis. Mahalanobis distance was calculated and a scatter plot was created to evaluate genetic dissimilarity. The results showed that the most effective method to determine the repeatability coefficient was PCA based on the covariance matrix. Twenty measurements are needed in order to achieve a coefficient of determination of 90%. Based on the measures of genetic dissimilarity, it was possible to differentiate clones and to recognize two genetically distinct groups.