中国菊科植物上拟盘梗霉属的新种和新组合*

拟盘梗霉属(Bremiella G.W.Wilson)霜霉,全世界已报道2个种。本文报道寄生于我国菊科植物上的1个新种及2个新组合。新种是寄生于茼蒿上的Bremiella multiformis Tao et Y.Qin sp.nov.。新组合是欧茼蒿上的Bremiella chrysanthemi-coronarii(Sawada)Tao comb.nov。及黄花蒿上的Bremiella artemisiae-annuae(Ling et M. C.Tai)Tao comb.nov.。对新种作了汉文及拉丁文描述,并附有形态图,还讨论了新种和新组合与近似种之间的区别。

NEW SPECIES AND NEW COMBINATION OF THE GENUS BREMIELLA ON COMPOSITAE OF CHINA

The genus Bremiella of Peronosporaceae was erected by Wilson in 1914, based upon a fungus described by Berlese as Peronospora megasperma. Two species of this genus were hitherto known from the world. In this paper, one new species and two new combinations parasitic on Compositae are reported. The new species is Bremiella multifermis sp. nov. on Chrysanthemum coronarium var. spatiosum Bailey. Two new combinations are: B. chaysanthemi-coronarii (Sawada) comb. nov. on Chrysanthemum coronarium L. and B. artemisiae-annuae (Ling et M. C. Tai) comb. nov. on Artemisia annua L. Bremiella multiformis sp. nov. is closely related to B. megasperma (on Viola spp.) and B. baudysii (on Berula erecta), but may be distinguished from the latter by its host plant, distribution, the polymorphous branches of sporangiophores and the shorter ultimate branchlets. New combinations of B. chrysanthemi-coronarii and B. artemisiaeannuae are transferred from the genus Plasmopara and Peronospora respectively. The common important characteristic of these two new combinations is the swollen ends of the sporangiophores. Differences between these new combinations and their related species are also discussed. Chinese and Latin diagnoses are given for the new species. Type specimens of the new species are deposited in Sichuan Agricultural College, Ya'an Sichuan, China.