Sampling of introduced and improved access to composition of a core collection of corn

Abstract

Aiming at the selection of accessions to compose a core collection of maize, were sampled access introduced and improved of Active Germplasm Bank at Embrapa Milho e Sorgo, located in Sete Lagoas, MG, Brazil. The sampling strategy was based in multivariate analysis, and adopted a sampling rate of 20% of accesses. Stratification of introduced accessions was in according with the country of origin, place of assessment and type of grain. For improved access was considered mainly the type of grain and the institution responsible for improvement of access. There is a need to perform the characterization and evaluation of many introduced and improved. It was possible to observe the existence of genetic variability among accessions. The plant height and thousand grain weight were the main contributors to the discrimination of genotypes. The combined use of the method of Tocher and as dissimilarity measure the Euclidian distance reversed and graphic dispersion analysis based on the first three principal components was effective. It was possible the selection of accessions to compose a core collection of maize based on multivariate analysis from the characterization and evaluation data.