Genetic divergence among white-type acai palm accessions based on morpho-agronomic characters

Abstract: The objective of this work was to quantify the genetic divergence among accessions of white-type acai palm, through morpho-agronomic characters. The accessions belong to the active acai palm germplasm bank of Embrapa Amazônia Oriental. Thirteen characters were evaluated in 26 accessions, originated from six municipalities in the state of Pará, Brazil. The data were subjected to deviance and multivariate analyses, based on the average Euclidean distance, and were grouped by Tocher’s method and the unweighted pair group method with arithmetic mean (UPGMA). The accessions differed for eight characters. The distances among accessions ranged from 0.64 to 2.62, with an average of 1.36, and four groups were formed by Tocher’s method and two by the UPGMA. Seven major components explained 88.03% of the variation, whose graphic dispersion showed the tendency of forming four groups. The characters weight of 100 fruits, number of rachillae per bunch, and fruit yield per bunch contributed the most to the divergence, and the accessions from the municipalities of Breves, Curralinho, and Limoeiro do Ajuru were the most divergent. Therefore, the accessions of white acai palm show strong divergence and variability, which favor the selection of desirable individuals.

摘要：本研究旨在通过形态农艺性状量化白型阿萨伊棕榈（white-type acai palm）种质间的遗传分化程度。供试种质均采自巴西农业研究公司东亚马孙分院（Embrapa Amazônia Oriental）的活性阿萨伊棕榈种质资源库。研究对26份源自巴西帕拉州6个市镇的种质材料的13项性状进行了评价。基于平均欧氏距离（Euclidean distance）对数据开展偏差分析与多元分析，并分别采用托彻聚类法（Tocher’s method）与非加权组平均法（unweighted pair group method with arithmetic mean, UPGMA）进行聚类分组。结果显示，8项性状在供试种质间存在显著差异。供试种质间的遗传距离范围为0.64至2.62，平均值为1.36；托彻聚类法将供试种质划分为4个类群，非加权组平均法则将其划分为2个类群。7个主成分解释了88.03%的总变异，其图形散点分布显示供试种质存在形成4个类群的趋势。百果重、每穗小穗轴数量以及单穗果实产量对遗传分化的贡献最大；来自布雷维斯、库拉林纽和利莫埃鲁杜阿尤鲁的种质材料遗传分化程度最高。综上，白型阿萨伊棕榈种质间存在较强的遗传分化与遗传变异，可为优良单株的选育提供有利条件。