Table_1_Natural and Cultural Processes Influencing Gene Flow Among Wild (atoq papa), Weedy (araq papa and k’ipa papa), and Crop Potatoes in the Andean Region of Southern Peru.DOCX

The Andean region is one of the areas with the earliest signs of food production systems and highest agrobiodiversity of the world, which resulted from millennia of domestication in a context of high ecosystem heterogeneity and human cultures valuing diversity for risk management. FAO has reported nearly 4000 varieties of cultivated potatoes still grown in the Andes, 3000 of them currently occurring in Peru. Such diversity has enormous sources of variation in wild (atoq papa) and weedy (araq papa and k’ipa papa) potatoes that coexist with crops, but their variation, interactions and mechanisms influencing diversification processes still require studies. In order to have a panorama of the variation and mechanisms influencing it in a regional setting, we studied biocultural factors favoring potatoes diversity in communities of Cusco and Apurimac, Peru. Our study documented the regional variation of wild, weedy, and cultivated potatoes recognized by local Quechua people and conducted semi-structured interviews to document their use, cultural value, and strategies of gene flow management implemented. We also studied their phenology, floral biology, flower visitors, and conducted experimental crosses between the wild S. candolleanum and 30 varieties of cultivated potatoes. We identified the wild potatoes S. acaule, S. brevicaule and S. candolleanum and 53 varieties of araq papa used and managed by local people. The latter provide nearly one third of the annual consumption of tubers by people interviewed and are, therefore, highly valued, maintained and managed in crop fields (chacras). People recognized that crosses between wild, weedy, and cultivated potatoes occur, and identified flower visitors and frugivores consuming their berries. Overlap of blooming periods and flower visitors of wild, weedy, and cultivated potatoes was recorded. Almost all flower visitors are shared among the different potato species and varieties, the bumble bees being particularly relevant in pollination of all taxa studied. We recorded seed production in nearly 35% of the experimental crosses. K’ipa papas are sets of mixtures of plants resulting from remaining tubers of cultivated potatoes, but also those from seeds that may result from hybridization of wild, weedy, and cultivated potatoes. Since local people commonly use k’ipa papa varieties and some of them are kept for planting in chacras, sexual reproduction in k’ipa papas is possibly one main mechanism of variation and source of new varieties of crops. Maintaining wild and weedy potatoes, and the natural and cultural mechanisms of gene flow is crucial for in situ conservation and generation of potato variation.

安第斯地区是全球最早出现粮食生产体系迹象、农业生物多样性（agrobiodiversity）最为富集的区域之一，这一格局是数千年来在高生态系统异质性的环境中历经驯化，且当地人类文化重视利用多样性进行风险管理共同塑造的结果。联合国粮食及农业组织（FAO）报告显示，目前安第斯地区仍种植着近4000个栽培马铃薯品种，其中约3000个品种现分布于秘鲁境内。这类多样性拥有丰富的变异来源，涵盖与栽培作物伴生的野生马铃薯（atoq papa）及杂草型马铃薯（araq papa与k’ipa papa），但目前学界对这些类群的变异特征、种间互作关系以及影响其多样化进程的机制仍有待深入研究。为全面厘清区域尺度下马铃薯多样性的变异特征及其影响机制，我们针对秘鲁库斯科与阿普里马克地区的社区开展了有利于马铃薯多样性保护的生物文化因子研究。本研究记录了当地克丘亚族群所认知的野生、杂草型及栽培马铃薯的区域变异情况，并通过半结构化访谈梳理了当地对这些马铃薯类群的利用方式、文化价值以及所采用的基因流管理策略。此外，我们还对其物候特征、花生物学特性及访花昆虫类群进行了调查，并开展了野生种S. candolleanum与30个栽培马铃薯品种间的杂交实验。研究共鉴定出当地居民利用和管理的野生马铃薯类群S. acaule、S. brevicaule与S. candolleanum，以及53个araq papa品种。该类杂草型马铃薯约占受访人群块茎年消费量的三分之一，因此在当地农田（chacras）中受到高度重视、维护与管理。当地居民证实，野生、杂草型与栽培马铃薯之间存在自然杂交现象，并识别出访花昆虫以及取食其浆果的食果动物类群。研究记录显示，野生、杂草型及栽培马铃薯的开花期与访花昆虫类群存在重叠，且几乎所有访花昆虫类群在不同马铃薯类群与品种间共享，其中熊蜂在所有研究类群的传粉过程中均发挥了尤为关键的作用。杂交实验结果显示，近35%的组合成功结籽。K’ipa papa是由栽培马铃薯块茎残留萌发形成的植物混合群体，同时也包含由野生、杂草型与栽培马铃薯杂交产生的种子萌发形成的植株。由于当地居民普遍种植k’ipa papa类群，且部分类群被留种用于农田种植，因此k’ipa papa的有性生殖可能是产生马铃薯变异并形成新品种的核心机制之一。维持野生与杂草型马铃薯种群，以及基因流的自然与文化调控机制，对于马铃薯的原位保护及变异类型的产生至关重要。