Phenotypic characterization of açai palm germplasm from the Marajó's archipelago and Baixo Tocantins territories

Abstract

The açai palm (Euterpe oleracea Mart.), a native of the Amazon region, is a food of great importance. Recently, due to the discovery of its nutraceutical properties, the rational production in upland areas has been encouraged. However, to support the rational implementation of its cultivation for fruit production, which is a sort of domestication process, it is necessary to identify its germplasm. The aim of this study was to evaluate and quantify the genetic diversity based on phenotypic characters among açai palm mother plants derived from 11 areas of the Amazonian estuary. Twenty-nine phenotypic descriptors were used: (i) 9 from the plant, (ii) 7 related to the fruit, and (iii) 13 of agronomic nature. Principal component analysis was used to assess the phenotypic variability from standardized data obtained from selected açai palm mother plants. In the selection of the descriptors, the methods of direct selection and selection with re-analysis were used. The disposal efficiency was estimated by comparing dissimilarity groups formed by 11 origins of the açai palms based on 29 original characters and 23 selected characters. The groups were formed using the average standardized Euclidean distance and Tocher's optimization method. All the analyses were performed using the GENES program. The selection of 79.31% of the descriptors used was significant and was considered sufficient for the evaluation of the açai palm germplasm for fruit production. The selected descriptors were shown to be capable of quantifying the phenotypic diversity of mother plants of this species, consistently grouping them using the optimization method. The cluster method showed small differences in the number and composition of the groups due to variability among the selected mother plants.