Evolution of Clonally-propagated Crops Under Human Influence: The Example of the Andean Tuber Crop Oxalis tuberosa

营养繁殖作物在养活世界方面发挥着巨大的作用，但我们对它们在进化和保护需求方面与种子繁殖作物的区别知之甚少。 克隆生长如何与人类对作物的选择和传播相互作用，从而影响植物驯化和作物进化，目前还知之甚少。 本研究使用安第斯山的块茎作物"奥卡"，紫花苜蓿，研究人类交换网络如何分布作物克隆的地理位置，以及它们如何影响克隆多样性在传统的自给农业。 具体而言，该项目比较了不同地区和其他克隆植物之间的奥卡的多样性，并使用空间统计分析模式的克隆和遗传结构的奥卡在秘鲁安第斯山脉。 DNA指纹（荧光AFLP）区分是否相似的外观块茎遗传克隆。 同样的数据也比较了奥卡和野生酢浆草物种，以检验关于奥卡多染色体组（多倍性）起源的假设（基于以前的DNA序列数据），培训讲习班和秘鲁学生参与研究将建立保护安第斯地区丰富的农业生物多样性的国际能力。 为了改善信息的获取，将以英文和西班牙文在科学论文和介绍以及非技术出版物中传播成果。 密歇根州立大学菲尔德博物馆和秘鲁利马国际马铃薯中心之间的合作有助于建立机构能力。 社会效益包括改进保护克隆作物多样性的战略，并增加对其驯化的了解。 由于对传统农业中任何作物的无性系分布知之甚少，这一结果不仅对保护奥卡的多样性很重要，而且将提高我们对人类对其他植物繁殖作物影响的理解。

Vegetatively-propagated crops play an enormous role in feeding the world, but we understand poorly how they differ from seed-propagated crops in their evolution and needs for conservation. Little is known about how clonal growth interacts with selection and dispersal of crops by humans to influence plant domestication and crop evolution. This research uses the Andean tuber crop "oca," Oxalis tuberosa, to study how human exchange networks distribute clones of the crop geographically and how they affect clonal diversity in traditional subsistence agriculture. Specifically, this project compares the diversity of oca among different localities and to other clonal plants, and uses spatial statistics to analyze patterns of clonal and genetic structure of oca across the Peruvian Andes. DNA fingerprinting (fluorescent AFLP) distinguishes whether similar-looking tubers are genetic clones. The same kind of data also compares oca to wild Oxalis species to test hypotheses (based on previous DNA sequence data) about the origins of oca's multiple chromosome sets (polyploidy).Training workshops and involvement of Peruvian students in the research will build international capacity for protecting the rich agricultural biodiversity of the Andean region. To improve access to information, results will be disseminated, in both English and Spanish, in scientific papers and presentations as well as in non-technical publications. Collaboration between The Field Museum, Michigan State University, and the International Potato Center in Lima, Peru, reciprocally builds institutional capacity. Societal benefits include improving strategies to conserve the diversity of clonal crops and increasing understanding of their domestication. Because so little is known about clonal distributions of any crop in traditional agriculture, the results will not only be important to conserve oca's diversity, but will improve our understanding of the human influence on other vegetatively-propagated crops.