Hart Jeffrey A
Harvard University Herbaria, 22 Divinity Avenue, Cambridge, MA 02138, U.S.A.
Cladistics. 1988 Dec;4(4):339-366. doi: 10.1111/j.1096-0031.1988.tb00519.x.
Abstract- The classical view of rust phylogeny is that rusts found on ferns and conifers are primitive, while rusts that parasitize angiosperms are advanced. This belief was based on the theory that primitive hosts harbor primitive parasites; that is, it assumed coevolution (co-speciation) of hosts and parasites. A cladistic analysis of 30 genera and 28 characters representative of the major patterns of rust fungi diversity is presented. The results of this analysis suggest that tropical short-cycle rusts on angiosperms form the cladistically basal group of rusts, while the rusts on conifers and ferns (Melampsoraceae sensu lato) form a nested terminal clade. These results suggest that rusts and their hosts have not undergone a long period of parallel cladogenesis (co-speciation); host transfer has probably been at least as frequent as co-speciation. The cladograms indicate evolutionary trends of spore stages and life history: urediniospores evidently preceded the evolution of aeciospores and pycniospores within Uredinales, and heteroecism is a derived condition which evolved at least several times. This study stresses the importance of making use of independent cladistic analyses of both host and parasite in order to test assumptions of coevolution and host transfer.
摘要——锈菌系统发育的传统观点认为，在蕨类植物和针叶树上发现的锈菌较为原始，而寄生于被子植物上的锈菌则较为进化。这种观点基于原始宿主携带原始寄生物的理论，也就是说，它假定宿主和寄生物是共同进化（共同物种形成）的。本文对代表锈菌真菌多样性主要模式的30个属和28个性状进行了分支系统分析。该分析结果表明，被子植物上的热带短周期锈菌构成了锈菌的分支基部类群，而针叶树和蕨类植物上的锈菌（广义的栅锈菌科）则形成一个嵌套的末端分支。这些结果表明，锈菌及其宿主并未经历长时间的平行分支发生（共同物种形成）；宿主转移可能至少与共同物种形成一样频繁。分支图显示了孢子阶段和生活史的进化趋势：在柄锈菌目内，夏孢子显然先于锈孢子和性孢子进化，转主寄生是一种衍生状态，至少进化了几次。本研究强调了利用宿主和寄生物的独立分支系统分析来检验共同进化和宿主转移假设的重要性。
