Posgrado en Ciencias Biológicas, Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, México.
Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Ciudad de México, México.
J Ethnobiol Ethnomed. 2020 May 1;16(1):22. doi: 10.1186/s13002-020-00368-2.
Most reports of domesticated plants that involve a domestication gradient or inter-specific hybridization in Mexico have focused on those used as food. This study provides knowledge about these processes in two aromatic medicinal plants, Agastache mexicana (Lamiaceae) and A. m. subsp. xolocotziana, widely used in Mexican traditional medicine for the treatment of gastrointestinal ailments and for their sedative effect. Different populations of A. mexicana along a gradient of domestication are found in the foothills of the Popocatepetl volcano of central Mexico, while in this same area the subsp. xolocotziana grows only in the cultivation, possibly a product of hybridization between A. mexicana and Agastache palmeri. This study links ethnobotanical, morpho-physiological, and phytochemical evidence to document the domestication of both taxa as well as elucidates the possible hybrid origin of the subsp. xolocotziana.
We analyze three groups of data derived from (1) 80 semi-structured interviews aimed at documenting the selection criteria related to the use and management of A. mexicana; (2) a cultivation experiment under homogeneous conditions, evaluating 21 floral, vegetative, and seed characters (that were important according to ethnobotanical information) in 97 plants corresponding to 13 populations of the taxa under study; and (3) the chemical profiles of the essential oils of these plants by means of a thin-layer chromatography.
By linking the three types of evidence, two evolutionary processes are distinguished: (1) A. mexicana occurs in the encouraged-cultivated phases of the domestication gradient and (2) A. m. subsp. xolocotziana may have originated through inbreeding depression or hybridization. These two cultivated plants show a domestication syndrome based upon organoleptic differentiation due to their dissimilar phytochemical composition and gigantism in flowers, seeds, and rhizomes (the last enhancing their asexual reproductive capacity). In addition to this, A. mexicana exhibits more intense floral pigmentation and foliar gigantism while subsp. xolocotziana presents floral albinism and partial seed sterility.
Two divergent evolutionary processes are reported for the domestication of A. mexicana as a result of the intensification of its use and management. The selection processes of these plants have resulted in alternation of the organoleptic properties based upon the divergence of the phytochemical composition. Also, gigantism has been selected in culturally preferred plant parts and in correlated structures. The preceding characteristics reinforce the joint use of these plants in infusion in Mexican traditionalmedicine for the treatment of gastrointestinal diseases and for their sedative effects.
墨西哥有关驯化梯度或种间杂交的驯化植物的大多数报告都集中在作为食物的植物上。本研究提供了两种芳香药用植物（Agastache mexicana（唇形科）和 A. m. subsp。xolocotziana）在这些过程中的知识，这些植物在墨西哥传统医学中广泛用于治疗胃肠道疾病和镇静作用。在墨西哥波波卡特佩特火山山麓发现了沿着驯化梯度的不同 A. mexicana 种群，而在同一地区，subsp。xolocotziana 仅在栽培中生长，可能是 A. mexicana 和 Agastache palmeri 之间杂交的产物。本研究将民族植物学、形态生理和植物化学证据联系起来，记录了这两个分类群的驯化过程，并阐明了 subsp。xolocotziana 的可能杂种起源。
我们分析了三组数据，这些数据来自于（1）80 次半结构访谈，旨在记录与使用和管理 A. mexicana 相关的选择标准；（2）在同质条件下进行的栽培实验，评估了 21 个与民族植物学信息相关的花、叶和种子特征（在 97 株来自研究分类群的植物中）；（3）通过薄层层析法对这些植物的精油化学图谱进行分析。
通过将三种类型的证据联系起来，可以区分出两个进化过程：（1）A. mexicana 出现在驯化梯度的鼓励栽培阶段，（2）A. m. subsp。xolocotziana 可能是由于近亲繁殖衰退或杂交而产生的。这两种栽培植物表现出基于器官分化的驯化综合征，这是由于它们不同的植物化学组成和花、种子和根茎的巨大化（最后增强了它们的无性繁殖能力）。除此之外，A. mexicana 表现出更强烈的花色素沉着和叶片巨大化，而 subsp。xolocotziana 则表现出花白化和部分种子不育。
由于对 A. mexicana 的使用和管理的加强，报告了两种不同的驯化过程。这些植物的选择过程导致了基于植物化学成分差异的感官特性的交替。此外，在文化上喜欢的植物部位和相关结构中选择了巨大化。前面的特征加强了这些植物在墨西哥传统医学中联合用于治疗胃肠道疾病和镇静作用的汤剂中的使用。
