Clonality may provide reproductive assurance for many threatened plants while limiting sexual reproductive success either through energetic tradeoffs or because clones are self-incompatible. Most stands of the Australian arid-zone plant Acacia carneorum, flower annually but low seed set and an absence of sexual recruitment now suggest that this species and other, important arid-zone ecosystem engineers may have low genotypic diversity. Indeed, our recent landscape-scale genetic study revealed that stands are typically monoclonal, with genets usually separated by kilometers. An inability to set sexually produced seed or a lack of genetically diverse mates may explain almost system-wide reproductive failure. Here, using microsatellite markers, we genotyped 100 seeds from a rare fruiting stand (Middle-Camp), together with all adult plants within it and its 4 neighboring stands (up to 5 km distant). As expected, all stands surveyed were monoclonal. However, the Middle-Camp seeds were generated sexually. Comparing seed genotypes with the single Middle-Camp genotype and those of genets from neighboring and other regional stands (n = 26), revealed that 73 seeds were sired by the Middle-Camp genet. Within these Middle-Camp seeds we detected 19 genotypes in proportions consistent with self-fertilization of that genet. For the remaining 27 seeds, comprising 8 different genotypes, paternity was assigned to the nearest neighboring stands Mallee and Mallee-West, approximately 1 km distant. Ironically, given this species' vast geographic range, a small number of stands with reproductively compatible near neighbors may provide the only sources of novel genotypes.

中文翻译：

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孤立和缺乏潜在配偶可能威胁到濒临灭绝的干旱区金合欢

克隆性可以为许多受威胁的植物提供繁殖保证，同时通过能量权衡或因为克隆是自我不相容的而限制有性繁殖成功。澳大利亚干旱区植物 Acacia carneorum 的大多数林分每年开花，但结实率低且无性补充现在表明该物种和其他重要的干旱区生态系统工程师可能具有较低的基因型多样性。事实上，我们最近的景观尺度遗传研究表明，林分通常是单克隆的，基因通常相距数公里。无法设置有性繁殖的种子或缺乏遗传多样性的配偶可能解释了几乎整个系统的生殖失败。在这里，我们使用微卫星标记对来自稀有果树（Middle-Camp）的 100 粒种子进行基因分型，连同其中的所有成年植物及其 4 个相邻的林分（最远 5 公里）。正如预期的那样，所有调查的林分都是单克隆的。然而，中营种子是通过性方式产生的。将种子基因型与单一 Middle-Camp 基因型和来自邻近和其他区域林分 (n = 26) 的基因型进行比较，发现有 73 粒种子是 Middle-Camp 基因的后代。在这些 Middle-Camp 种子中，我们检测到 19 种基因型，其比例与该基因的自体受精一致。对于剩余的 27 粒种子，包括 8 种不同的基因型，亲子关系被分配到最近的相邻植株 Mallee 和 Mallee-West，相距约 1 公里。具有讽刺意味的是，鉴于该物种的广阔地理范围，