Abstract:
Crop diversity is shaped by biological and social processes interacting at different spatiotemporal scales. Here, we combined population genetics and ethnobotany to investigate date palm (Phoenix dactylifera L.) diversity in Siwa Oasis, Egypt. Based on interviews with farmers and observation of practices in the field, we collected 149 date palms from Siwa Oasis and 27 uncultivated date palms from abandoned oases in the surrounding desert. Using genotyping data from 18 nuclear and plastid microsatellite loci, we confirmed that some named types each constitute a clonal line, that is, a true-to-type cultivar. We also found that others are collections of clonal lines, that is, ethnovarieties, or even unrelated samples, that is, local categories. This alters current assessments of agrobiodiversity, which are visibly underestimated, and uncovers the impact of low-intensity, but highly effective, farming practices on biodiversity. These hardly observable practices, hypothesized by ethnographic survey and confirmed by genetic analysis, are enabled by the way Isiwans conceive and classify living beings in their oasis, which do not quite match the way biologists do: a classic disparity of etic versus. emic categorizations. In addition, we established that Siwa date palms represent a unique and highly diverse genetic cluster, rather than a subset of North African and Middle Eastern palm diversity. As previously shown, North African date palms display evidence of introgression by the wild relative Phoenix theophrasti, and we found that the uncultivated date palms from the abandoned oases share even more alleles with this species than cultivated palms in this region. The study of Siwa date palms could hence be a key to the understanding of date palm diversification in North Africa. Integration of ethnography and population genetics promoted the understanding of the interplay between diversity management in the oasis (short-time scale), and the origins and dynamic of diversity through domestication and diversification (long-time scale).
摘要:
作物多样性是由在不同时空尺度上相互作用的生物和社会过程形成的。这里,我们将种群遗传学和民族植物学相结合,研究了锡瓦绿洲的椰枣(PhoenixdactyliferaL.)多样性,埃及。根据对农民的访谈和实地实践的观察,我们从Siwa绿洲收集了149个枣树,从周围沙漠的废弃绿洲中收集了27个未耕种的枣树。使用来自18个核和质体微卫星基因座的基因分型数据,我们证实了一些命名类型各自构成了一个克隆系,也就是说,真正的品种。我们还发现其他人是克隆系的集合,也就是说,民族品种,甚至是不相关的样本,也就是说,本地类别。这改变了目前对农业生物多样性的评估,明显被低估了,揭示低强度的影响,但是非常有效,关于生物多样性的耕作方法。这些几乎观察不到的实践,通过人种学调查假设并通过遗传分析证实,通过Isiwans对绿洲中的生物进行构思和分类的方式来实现,这与生物学家的做法并不完全吻合:一种经典的eticvs.emic分类。此外,我们确定Siwa枣树代表了一个独特且高度多样化的遗传簇,而不是北非和中东棕榈多样性的一个子集。如前所述,北非枣树显示出野生亲戚凤凰城theophrasti渗入的证据,我们发现,来自废弃绿洲的未种植的枣树与该物种共享的等位基因比该地区的栽培棕榈更多。因此,对Siwa枣树的研究可能是理解北非枣树多样化的关键。人种学和种群遗传学的整合促进了对绿洲多样性管理之间相互作用的理解(短期规模),以及通过驯化和多样化(长时间尺度)实现多样性的起源和动态。