Department of Plant Sciences, Mail Stop 2, University of California, Davis, One Shields Avenue, Davis, California 95616, USA.
Am J Bot. 2012 Mar;99(3):585-604. doi: 10.3732/ajb.1100326.
Understanding patterns and processes associated with domestication has implications for crop development and agricultural biodiversity conservation. Semi-domesticated crops provide excellent opportunities to examine the interplay of natural and anthropogenic influences on plant evolution. The domestication process has not been thoroughly examined in many tropical perennial crop species. Chrysophyllum cainito (Sapotaceae), the star apple or caimito, is a semi-domesticated species widely cultivated for its edible fruits. It is known to be native to the neotropics, but the precise geographic origins of wild and cultivated forms are unresolved.
We used nuclear ribosomal ITS sequences to infer phylogenetic relationships among C. cainito and close relatives (section Chrysophyllum). We employed phylogeographic approaches using ITS and plastid sequence data to determine geographic origins and center(s) of domestication of caimito.
ITS data suggest a close relationship between C. cainito and C. argenteum. Plastid haplotype networks reveal several haplotypes unique to individual taxa but fail to resolve distinct lineages for either C. cainito or C. argenteum. Caimito populations from northern Mesoamerica and the Antilles exhibit a subset of the genetic diversity found in southern Mesoamerica. In Panama, cultivated caimito retains high levels of the diversity seen in wild populations.
Chrysophyllum cainito is most closely related to a clade containing Central and South American C. argenteum, including subsp. panamense. We hypothesize that caimito is native to southern Mesoamerica and was domesticated from multiple wild populations in Panama. Subsequent migration into northern Mesoamerica and the Antilles was mediated by human cultivation.
理解与驯化相关的模式和过程对作物开发和农业生物多样性保护具有重要意义。半驯化作物为研究自然和人为因素对植物进化的相互作用提供了极好的机会。许多热带多年生作物的驯化过程尚未得到彻底研究。番荔枝科（番荔枝科）的星苹果或 caimito 是一种半驯化的物种，因其可食用的果实而被广泛种植。它被认为原产于新热带地区，但野生和栽培形式的确切地理起源尚未解决。
我们使用核核糖体 ITS 序列推断 C. cainito 及其近亲（Chrysophyllum 节）的系统发育关系。我们采用 ITS 和质体序列数据的系统地理学方法来确定 caimito 的地理起源和驯化中心。
ITS 数据表明 C. cainito 与 C. argenteum 密切相关。质体单倍型网络揭示了个别分类群特有的几个单倍型，但未能为 C. cainito 或 C. argenteum 确定明显的谱系。来自中美洲北部和安的列斯群岛的 caimito 种群表现出中美洲南部发现的遗传多样性的一部分。在巴拿马，栽培的 caimito 保留了野生种群中所见的多样性的高水平。
Chrysophyllum cainito 与包含中美洲和南美洲 C. argenteum 的一个分支最密切相关，包括 subsp. panamense。我们假设 caimito 原产于中美洲南部，并从巴拿马的多个野生种群中驯化而来。随后向北迁移到中美洲和安的列斯群岛是由人类栽培介导的。
