Data from: Mating system and genetic composition of the macaw palm (Acrocomia aculeata): implications for breeding and genetic conservation programs

Acrocomia aculeata (Arecaceae), a palm endemic to South and Central America, is a potential oil crop. Knowledge of the mating system of this species is limited to its reproductive biology and to studies using molecular markers. The present study analyzed genetic diversity between its developmental stages and determined its prevailing mating system in order to support genetic conservation and breeding programs. We tested nine microsatellite markers in 27 mother trees (adult plants) and 157 offspring (juvenile plants) from the southeastern region of Brazil. Heterozygosity levels differed between the two studied life stages, as indicated by the fixation index of adult and juvenile trees, suggesting that selection against homozygotes occurs during the plant life cycle. The mating system parameters analyzed indicate that A. aculeata is predominantly outcrossing (allogamous). However, its low levels of selfing suggest that there is individual variation with regard to self-incompatibility, which can be a survival strategy in isolated or fragmented habitats. Deviations in variance effective size were detected because of high mating rates among relatives and correlated matings. These findings indicate that the main source of inbreeding results from biparental inbreeding in the population and that the progenies are predominantly composed of full-sibs. The information provided by this study on the ecology and reproduction dynamics of A. aculeata should be useful to both breeding and genetic conservation programs, allowing the development of more precise mathematical models and the estimation of the appropriate number of mother trees for seed collection.刺叶椰子（Acrocomia aculeata，棕榈科Arecaceae）是中南美洲特有的棕榈物种，具有潜在油料作物开发价值。目前针对该物种交配系统的认知，仅覆盖其繁殖生物学特征以及基于分子标记的相关研究。本研究分析了其不同发育阶段的遗传多样性，并明确了其主流交配系统，以期为遗传保护与育种计划提供支撑。本研究针对巴西东南部地区的27株母树（成年植株）与157株子代（幼龄植株），开展了9个微卫星标记（microsatellite markers）的检测工作。两个研究生活史阶段的杂合度水平存在显著差异，成年与幼龄植株的固定指数（fixation index）也印证了这一点，表明植物生命周期中存在针对纯合子的选择作用。交配系统参数分析结果显示，刺叶椰子以异交（outcrossing，allogamous）为主。但其较低的自交率提示，自交不亲和性存在个体间差异，这或许是物种在孤立或生境破碎化环境下的生存策略。研究还检测到方差有效种群大小（variance effective size）出现偏差，这源于较高的近亲交配率与相关交配事件。上述发现表明，种群内的近交主要来源于双亲近交（biparental inbreeding），且子代群体主要由全同胞家系（full-sibs）构成。本研究揭示的刺叶椰子生态学与繁殖动态信息，可为育种与遗传保护计划提供参考，助力构建更精准的数学模型，并确定种子采集所需的适宜母树数量。