| Popis: |
An accurate knowledge of the life-histories of fungi is of the greatest importance, not only to taxonomy, but especially to plant pathology. As many parasitic fungi possess two or more fruiting stages, in some cases occurring on different hosts, it is necessary to have a full knowledge of their complete course of development in order to know how they are reproduced and distributed, and to devise adequate methods of combating or preventing them. The fungi producing the diseases known as anthracnoses, which attack a great variety of wild and cultivated plants, have been described chiefly as species of Gloeosporium and Colletotrichum. The positive connection of these conidial forms with ascogenous stages was, so far as we are aware, first demonstrated by means of pure cultures by Professor G. F. ATKINSON, as reported by Miss STONEMAN" in i898. F-UCKEL2 in i869 gave Gloeosporium juglandis Lib. (Marsonia juglandis (Lib.) Sacc.) as the spermagonial form of Gnomonia leptostyla (Fr.) Ces. & De Not., which occurs on Juglans regia. It has uniseptate conidia, and the ascospores are also uniseptate, which facts seem to indicate that it is not congeneric with the organisms with which we are concerned at present. F-UCKEL'S statement in regard to the connection between these two forms was based simply upon the association of the two on the same leaf, and was merely a guess. KLEBAHN3, however, has recently demonstrated by pure cultures and infection experiments that FtCKEL was correct in this case. Other forms studied by KLEBAHN, which have passed under the name of Gloeosporium, are G. nervisequum (Fuck.) |
