DISSERTATION RESEARCH: Systematics of Cupressus and Chamaecyparis (Cupressaceae)

康奈尔大学的凯文·尼克松博士和达蒙·利特尔先生获得了一笔赠款，用于研究柏属（柏树）与乔木（崖柏）和杜松（杜松）等密切相关物种的进化关系。这些物种因其有吸引力的万年青树叶和宜人的“雪松”香味而被广泛种植。他们的木材是一些经济上的重要性，由于其耐用性和抗腐性（用于例如，铅笔、雪松箱、壁板、甲板和屋顶瓦）。由于其狭窄的地理分布，一种柏树被美国政府列为濒危物种，另一种被列为受威胁物种。这些物种的DNA序列和形态特征将被用于推断进化历史和划定柏树的物种（关于物种数量存在很大争议）。其他将被调查的问题包括进化专门适应极端生境类型，种子传播机制的进化，以及柏树物种之间的杂交。这项研究的结果将突出这些物种的诊断特征，并提供识别键和其他信息，以便专家和非专家（例如，林务员、植物育种家、园艺家、生态学家等）可以很容易地识别标本。此外，将提供所有柏树物种的完整描述。其他专家将能够利用在这项研究过程中开发的工具来研究其他针叶树的进化。

A grant has been awarded to Dr. Kevin Nixon and Mr. Damon Little at Cornell University to study the evolutionary relationships of the genus Cupressus (cypress) and closely related species such as arborvitae (Thuja) and junipers (Juniperus). These species are widely cultivated for their attractive evergreen foliage and pleasant "cedar" scent. Their wood is of some economic importance due to its durability and resistance to rot (used in e.g., pencils, cedar chests, siding, decks, and roofing shingles). Due to their narrow geographic distributions, one species of cypress is classified by the United States government as endangered and another is listed as threatened. DNA sequences and morphological characteristics of these species will be used to infer the evolutionary history and delimit the species of cypress (there is great controversy concerning the number of species). Other questions that will be investigated include the evolution specialized adaptations to extreme habitat types, evolution of seed dispersal mechanisms, and hybridization between cypress species.The result of this research will highlight diagnostic characteristics of these species and provide identification keys and other information so specialists and non-specialists (e.g., foresters, plant breeders, horticulturists, ecologists, etc.) can easily identify specimens. In addition a complete description of all cypress species will be provided. Other specialists will be able to the tools developed during the course of this research to study evolution in other conifers.