. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 137. Fig. 91.—S. urnula, monilifoTin conidia with disjuDctois. After Woronin. possess Botrytis forms (see pp. 141 and 578), others Monilia (see pp. 139 and 558) forms of conidial fructification. In addition to these there may be gonidia, which appear to be degenerate, f unctionless conidia. In some species there is no known spore form except that in the ascus. S. ledi Now. is of especial interest as the one .fungus outside of the Uredinales that exhibits hetercecism.^^^ Many forms found upon sepa
. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 137. Fig. 91.—S. urnula, monilifoTin conidia with disjuDctois. After Woronin. possess Botrytis forms (see pp. 141 and 578), others Monilia (see pp. 139 and 558) forms of conidial fructification. In addition to these there may be gonidia, which appear to be degenerate, f unctionless conidia. In some species there is no known spore form except that in the ascus. S. ledi Now. is of especial interest as the one .fungus outside of the Uredinales that exhibits hetercecism.^^^ Many forms found upon separate hosts and presenting shght differences under the micro- scope, often even no microscopic differences, have been named as separate species. Only long careful culture studies and inoculation ex- periments will determine which of these species are valid, where more segregation, where more aggregation is needed. The mere association of Botrytis or Monilia conidial forms with Sclerotinia, in the same host, has repeatedly led to the assumption that such forms were genetic- ally connected. Such assumptions are not warranted. Only the most careful study and most complete evidence justify such conclusions. The genus contains some fifty species which are divided into two subgenera; Stromatinia Boud., forming sclerotia in the fruits of the host; Eusclerotinia Rehm forming sclerotia in or on stems and leaves of the host. When conidia are known those of Stromatinia are of the Monilia type and those of Eusclerotinia of the Botrytis type. Each group contains important economic species. S. fructigena, S. cinerea and S. laxa.^"- "• ^s. 291-295 These forms are perpetuated chiefly by their conidia. The ascus-forms are much less often seen. When the conidia fall upon the peach, the mycelium develops and penetrates even the soimd skin, then rapidly induces a brown rot. The mycelium within the tissue is septate, much branched, and light brown in color. It soon proceeds to form a s
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
