At present, intelligent and sustainable agriculture presupposes a compromise between maximising crop yield and minimising its risk of genetic vulnerability. Breeding programmes should implement strategies that allow the development of superior genotypes and preserve genetic diversity, especially in perennial plants. The Macaúba palm (Acrocomia aculeata) is a species with the potential to produce oil at a level comparable to that of the oil palm, even in water-deficient areas, which motivates its commercial interest and drives an increase in demand for seedlings from natural populations for commercial plantations. Therefore, to evaluate the impact of this selection procedure on the reduction of genetic diversity and, consequently, the genetic vulnerability of commercial planting, in the present study we analysed the population mating system and the genetic diversity of Open-Pollinated Progenies (OPPs) from selected seed-trees in relation to the genetic diversity of respective native populations (NPs). To achieve this, we evaluated the mating system and genetic diversity employing 14 microsatellite markers (SSR). The mating system indices estimated for A. aculeata palm indicated that the species present a mixed mating system () with a predominance of outcrossing. However, at the population level, the outcrossing rate ranged from . The biparental inbreeding rate was considered moderate (), with some variation between populations (from 0.0005 to 0.275). The multilocus correlated paternity was , ranging from 0 to 0.112 at population level, indicating that a significant portion of the progeny consisted of half-sibs. The results demonstrate that there was no significant loss of genetic diversity of OPPs derived from artificial selection within NPs. In the OPPs the number of alleles (Na = 2.55) was similar to that of NP (Na = 2.56). Furthermore, the mean values of observed heterozygosity (H_O) between NP and OPPs were similar, with a mean of 0.366 and 0.356, respectively. In conclusion, the procedure adopted to produce commercial seedlings in the present study should not represent a high risk of genetic vulnerability. In addition, our results will provide a guidance to breeders regarding selection intensity in both natural and improved populations, aiming to optimise the advancement of generations, thereby maximising future genetic gains while preserving genetic diversity. However, we recommend verifying the outcrossing rate and genetic diversity at the population level, as these factors could have significant effects on the vulnerability of the species and the macaúba crop.

中文翻译：

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评估马卡乌巴棕榈的遗传脆弱性 [Acrocomia aculeata (Jacq.) Lodd。ex Mart.]通过交配系统和开放授粉后代的遗传多样性

目前，智能和可持续农业的前提是在最大化作物产量和最小化其遗传脆弱性风险之间取得折衷。育种计划应实施允许开发优良基因型并保留遗传多样性的策略，特别是在多年生植物中。马卡乌巴棕榈 ( Acrocomia aculeata ) 是一种即使在缺水地区也具有与油棕相当的产油潜力的物种，这激发了其商业利益并推动自然种群对树苗的需求增加用于商业种植园。因此，为了评估这种选择程序对遗传多样性减少的影响，从而评估商业种植的遗传脆弱性，在本研究中，我们分析了群体交配系统和来自开放授粉后代（OPP）的遗传多样性。根据各自本地种群（NP）的遗传多样性选择种子树。为了实现这一目标，我们利用 14 个微卫星标记 (SSR) 评估了交配系统和遗传多样性。对A. aculeata棕榈的交配系统指数估计表明该物种呈现混合交配系统（${\widehat{t}}_{米}=0.877$），以异交为主。然而，在人口水平上，异型杂交率范围为${\widehat{t}}_{米}=0.986\text{到}1.00$。双亲近交率被认为是中等的（${\widehat{t}}_{米}-{\widehat{t}}_s=0.312$），群体之间存在一些差异（从 0.0005 到 0.275）。多位点相关亲子关系为${\widehat{r}}_p=0.389$，在群体水平上范围从 0 到 0.112，表明后代的很大一部分由半同胞组成。结果表明，NP 内人工选择产生的 OPP 遗传多样性没有显着丧失。OPP 中的等位基因数量 (Na = 2.55) 与 NP 中的等位基因数量 (Na = 2.56) 相似。此外，观察到的 NP 和 OPP 之间的杂合度 ( H _O )平均值相似，平均值分别为 0.366 和 0.356。总之，本研究中用于生产商业苗木的程序不应代表遗传脆弱性的高风险。此外，我们的结果将为育种者提供关于自然群体和改良群体的选择强度的指导，旨在优化世代进步，从而在保留遗传多样性的同时最大化未来的遗传收益。然而，我们建议在种群水平上验证异交率和遗传多样性，因为这些因素可能会对物种和马卡乌巴作物的脆弱性产生重大影响。