. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 149 earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old leaves bearing the latter fimgus were wintered out-doors in filter paper and in the spring were found with this ascigerous stage. The ascospores were isolated, grown in pure culture and typical conidia were produced. The ascospores also infected the host leaves successfully producing there the typical Gloeosporium. The conidial stage is the only one ordinarily seen. The acervuli are subepidermal elevating the epidermis to form a
. The fungi which cause plant disease . Plant diseases; Fungi. THE FUNGI WHICH CAUSE PLANT DISEASE 149 earlier known as Gloeosporium ribis (Lib.) Mont. & Desm. Old leaves bearing the latter fimgus were wintered out-doors in filter paper and in the spring were found with this ascigerous stage. The ascospores were isolated, grown in pure culture and typical conidia were produced. The ascospores also infected the host leaves successfully producing there the typical Gloeosporium. The conidial stage is the only one ordinarily seen. The acervuli are subepidermal elevating the epidermis to form a pustule which eventually ruptures and allows the spores to escape as a gelatinous whitish or flesh-colored mass. The spores are curved and usually larger at one end than at the other. Fabraea Saccardo (p. 147) This is a genus of some ten species of small leaf parasites which much resemble Pseudopeziza but differ from it in its 2 to 4-celled spores. F. maculata (Lev.) Atk.*^ The perfect stage is common on pear and quince leaves which have wintered naturally. When such leaves are wet the white 8-spored asci may be seen crowding through the surface in small eUiptical areas. The apothecium is paraphysate; the spores hyaline and 2-celled. Conidial form (=Entomo- sporium maculatum) on leaves and fruits; acervuli, black, subepidermal, the epidermis breaking away to expose the pio. loe.—F. maculata. i, acemiius of „„„-«„ ViiTolinr^ conidial stage in section; 3, spores. spore mass; spores hyahne After Southworth. 18-20 X 12 fi, 4-cells in a cluster, the lateral cells smaller, depressed; stipe filiform 20 x m; the other cells with long setae. Atkinson ^' proved the connection of the ascigerous with the conidial form by ctiltiv'ating the conidia from the ascospores. The conidial form is very common and destructive on pear and quince leaves and fruit. The mycelium which abounds in the diseased spot is hyaline when young, dark when old. It collects to form a. Please note th
Size: 1841px × 1358px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
