Dissertation Research: Phylogeny of Tribe Trichocereeae and Resolution of a Thorny History of Reticulate Evolution and Polyploidy in Haageocereus (Cactaceae)

仙人掌科(仙人掌科仙人掌)是一个约2000种的大科，仅限于美洲大陆，但现在在世界各地种植。虽然大多数仙人掌是在沙漠中发现的，但它们也可以在潮湿的地方作为附生植物生长。由秘鲁和玻利维亚组成的区域拥有世界上第二高的仙人掌物种多样性，也可能是该科的可能起源地。尽管仙人掌的体型和生态重要性很大，但很少有研究考察该科之间的亲缘关系。大多数南美洲的仙人掌物种属于旋毛虫族，其中约80%是各自国家特有的。旋毛虫亚科成员之间的关系和物种边界知之甚少。旋毛虫表现出很大的形态变异性和复杂的繁殖模式，传统上归因于杂交、多倍体(或基因组加倍)和营养繁殖等现象。鉴于大多数南美洲国家最大和人口最多的城市都位于这些仙人掌的自然栖息地，毛虫，特别是Haageocereus，正变得越来越容易受到人类的干扰。系统发育是更好地了解这些生物的生物学并促进随后的生态和/或保护研究的关键的第一步。毛滴虫族的系统发育将被用作一个框架：1)解决毛滴虫科各属之间的关系；2)解决毛滴虫属种之间的关系；3)确定杂交种和多倍体在毛滴虫科和其他毛滴虫科中的存在和重要性；4)研究该组的生物地理格局；5)研究濒危物种的遗传多样性。Haageocereus可能是旋毛虫科中形态最多样化的属，它将作为一个模式系统，并将利用DNA测序和微卫星技术在物种和种群水平上进行详细研究。关于毛滴虫科的研究将通过出版物、毛滴虫科网站、会议、研讨会和在仙人掌盛产地区的大学和植物机构开设的课程继续产生教育影响。重要的是，政府机构INRENA(国家自然资源研究所)将利用这项关于当地仙人掌植物保护状况的工作和附带的数据库(Arakaki和Ostolaza，2005年出版)来制定秘鲁仙人掌的管理政策。该项目还将涉及与玻利维亚和智利的植物学家合作。

The cactus family (Cactaceae) is a large family of approximately 2000 species restricted to the American continent, but now cultivated all over the world. Although most cacti are found in deserts, they can also prosper as epiphytes in humid places. The region comprising Peru and Bolivia has the second highest species diversity for Cactaceae in the world and also may represent a possible site of origin for the family. In spite of the large size and ecological importance of Cactaceae, few studies have examined relationships in the family. Most South American species of cacti belong to tribe Trichocereeae, with about 80% of them endemic to their respective countries. Relationships and species boundaries among members of Trichocereeae are poorly understood. Trichocereeae show great morphological variability and complex reproductive patterns, traditionally attributed to phenomena such as hybridization, polyploidy (or genome doubling), and vegetative propagation. The Trichocereeae, and Haageocereus in particular, are becoming more and more vulnerable to human disturbance given that the largest and most populated cities in most South American countries are located in the natural habitats of these cacti. A phylogeny is a crucial first step to obtain a better understanding of the biology of these organisms and to facilitate subsequent ecological and/or conservation studies. The phylogeny of tribe Trichocereeae will be used as a framework for: 1) resolving relationships among genera in Trichocereeae; 2) resolving relationships among species of Haageocereus; 3) determining the presence and importance of hybridization and polyploidy in Haageocereus and other Trichocereeae; 4) examination of biogeographic patterns in the group; 5) examination of genetic diversity in endangered species of Haageocereus. Haageocereus, perhaps the most morphologically diverse genus in Trichocereeae, will serve as a model system and will be investigated in detail at the species and population level employing DNA sequencing and microsatellite techniques. Studies on Trichocereeae will continue to have educational impact through dissemination of the results through publications, the Trichocereeae website, conferences, seminars and courses offered at universities and botanical institutions located in cacti-rich areas. Importantly, the governmental institution INRENA (National Institute of Natural Resources) will use this work on the conservation status of endemic Cactaceae and accompanying database (Arakaki and Ostolaza 2005 in press) to establish management policies for Peruvian cacti. The project will also involve collaboration with botanists in Bolivia and Chile.