. The British rust fungi (Uredinales) their biology and classification. Rust fungi. BASIDIOSPORES â , moreover, the four cells may not be formed ; the " basidium " ly resemble, more or less, an ordinary germ-tube and possibly ly function as such. Even if the four cells are formed, they ly germinate by the protrusion of a germ-tube, which pre- mably can cause infection by penetrating the cuticle (see )ons, 1912, p. 225). But, with access of air, each cell forms a jrigma and a basidiospore as previously described. These aidia are obviously adapted for wind-dispersion. If they [ght on a
. The British rust fungi (Uredinales) their biology and classification. Rust fungi. BASIDIOSPORES â , moreover, the four cells may not be formed ; the " basidium " ly resemble, more or less, an ordinary germ-tube and possibly ly function as such. Even if the four cells are formed, they ly germinate by the protrusion of a germ-tube, which pre- mably can cause infection by penetrating the cuticle (see )ons, 1912, p. 225). But, with access of air, each cell forms a jrigma and a basidiospore as previously described. These aidia are obviously adapted for wind-dispersion. If they [ght on a suitable surface, they send forth a short tube which variably bores straight through the cuticle into the under- ing epidermal cell of the plant, and there begins to form mycelium. The only instance in Fuccinia known to the con- aryi, out of the many observations that have been made and jured of this process, is De Bary's record of the case (Ann. â¢d. Nat. Bot. 4. xx, 1863, pp. 88-9) where the germ-tubes of the basidiospores of Puccinia Dianthi () penetrated through the stom- atal openings of Dianthus harbatus (Fig. 24). In grasses and sedges, it is easy to see that the siliceous cuticle would present a great ob- g. 24. Basidiospores (6) of , , , ,, ^ » , , , Puccinia Dianthi, sermina- stacle to the entry ot such a tube, ting on leaf of Dianthus, ^^jj^jg j^q^ impeding germ-tubes showing the germ-tubes mak- . i i ing straight for the stomata which enter through a stoma, and (afterDeBary'sfigure). x390. ^j^-^ -^ probably the reason why cidia are so rare on the order Glumiflorse. In the heteroecious )ecies no one has yet brought forward indisputable evidence ) show that basidiospores can infect the host which bore the sleutospores, although statements to that effect are made. The shapes of basidiospores are not irregular; they are lore or less constant in each group. In Puccinia and Uromyces ley are ovate, somewhat flattened on one side, or kidney- laped. In the Phragmi
Size: 2132px × 1172px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishercambr, bookyear1913
