Structure of the phenotypic variability of fruit and seeds of Dipteryx alata vogel (Fabaceae)

Abstract Dipteryx alata Vogel (“baru tree”) is a fruit species native to the Brazilian Cerrado and presents a multiplicity of uses, constituting a priority species for domestication and cultivation studies. The objective of the current study was to characterize fruit and seeds of D. alata from several regions of the Brazilian Cerrado biome to support strategies for ex situ conservation and utilization of the genetic variability of the species. Fruits were collected from 25 subpopulations, sampling six mother plants per subpopulation, with collection of at least 25 fruits per plant. The physical trait data of the fruits and seeds were submitted to descriptive analysis, analysis of variance and correlation among traits. There was significant variation for all traits among subpopulations and among individuals within subpopulations. The highest proportion of variability was observed among individuals within subpopulations. The phenotypic differentiation among subpopulations was higher for fruit traits compared to seed traits. The correlation analysis showed the existence of significant correlations for most of the traits pairs in the different hierarchical levels. It was concluded that D. alata presents phenotypic variability to support germplasm collection programsand formation of base populations for breeding programs, recommending the sampling in several locations to ensure an adequate representativeness of the phenotypic variability.

摘要：巴拉鲁树（Dipteryx alata Vogel，baru tree）是原产于巴西塞拉多（Brazilian Cerrado）生物群区的果树物种，兼具多种开发用途，是驯化与栽培研究的优先物种。本研究旨在对巴西塞拉多生物群区多个区域的巴拉鲁树果实与种子进行表型性状分析，为该物种的迁地保护（ex situ conservation）及遗传变异利用策略提供支撑。研究共采集25个亚种群的果实样本，每个亚种群选取6株母株，每株母株至少采集25颗果实。对果实与种子的物理性状数据开展描述性统计分析、方差分析及性状间相关性分析。结果显示，所有性状在亚种群间及亚种群内个体间均存在显著变异，且亚种群内个体间的变异占总变异的比例最高。相较于种子性状，亚种群间的果实性状表型分化程度更高。相关性分析表明，在不同层级下，绝大多数性状对之间均存在显著相关性。研究结论显示，巴拉鲁树具有丰富的表型变异，可为种质资源（germplasm）收集计划及育种项目基础种群构建提供支撑，建议在多个区域开展采样以确保表型变异的充分代表性。