Barr D J
Biosystems. 1978 Apr;10(1-2):153-65. doi: 10.1016/0303-2647(78)90037-0.
Thallus development, zoospore size, zoospore ultrastructural complexity and organization, and flagellum length are cited as important in phylogeny of the Chytridiales (chytrids) and should be the bases for this classification. Discharge of zoospores is also cited as important although emphasis is not placed on operculation. It is proposed that simple, eucarpic, monocentric chytrids which discharge zoospores following dissolution of the sporangium wall evolved into multipapilliate species of Rhizophydium and 2 lines of evolution from these species are documented with examples. In one line they evolved into single-pored species such as R. pollinis-pini, then to Chytridium and tendochytrium-like chytrids and to polycentric chytrids such as Nowakowskiella and Cladochytrium. The second line evolved from multipapilliate Rhizophydium species to Phlyctochytrium and Entophlyctis, and to the order Blastocladiales. Rhizophlyctis rosea and some olpidiaceous chytrids, because of a fibrillar rhizoplast in their zoospores do not appear close to Rhizophydium-related chytrids and may require separate subordinal rank in classification. It is proposed that zoospores of the advanced members of the class Chytridiomycetes have reached limits for further zoospore development because of size; however, the zoospore is no longer essential for them because they have developed a filamentous habit of growth.
菌体发育、游动孢子大小、游动孢子超微结构的复杂性与组织以及鞭毛长度被认为在壶菌目（壶菌）的系统发育中很重要，应作为该分类的依据。游动孢子的释放也被认为很重要，尽管重点不在于孔盖。有人提出，那些在孢子囊壁溶解后释放游动孢子的简单、真果、单核壶菌进化成了多乳头的根壶菌属物种，并举例说明了从这些物种开始的两条进化路线。在一条路线中，它们进化成单孔物种，如松花粉根壶菌，然后进化成像壶菌属和腱壶菌属那样的壶菌，再进化成多核壶菌，如诺瓦科夫斯基壶菌属和枝壶菌属。第二条路线从多乳头的根壶菌属物种进化到集壶菌属和内集壶菌属，再进化到芽枝霉目。由于其游动孢子中有纤维状的根丝体，玫瑰集壶菌和一些油壶菌科壶菌似乎与根壶菌属相关壶菌关系不密切，在分类中可能需要单独划分亚目等级。有人提出，壶菌纲高级成员的游动孢子由于大小原因已达到进一步发育游动孢子的极限；然而，游动孢子对它们来说已不再是必需之物，因为它们已形成丝状生长习性。
