. The fungi which cause plant disease . Plant diseases; Fungi. 204 THE FUNGI WHICH CAUSE PLANT DISEASE Germ tubes from ascospores or conidia enter the cortex and develop a rich mycelimn in the sieve tubes and soft host. This advances most rapidly during the dormant period of the bast. White or yellow stromata the size of a pin- head appear and bear numerous conidia. Later come the red perithecia whose ascospores ripen in winter or spring. N. ribis (Tode) Rab. Fig. 144.—n. ipo- Cespitose, Stroma compact; perithecia sub- of perithecia. globose, smooth; ostiole papillate; asci subclavate, After H
. The fungi which cause plant disease . Plant diseases; Fungi. 204 THE FUNGI WHICH CAUSE PLANT DISEASE Germ tubes from ascospores or conidia enter the cortex and develop a rich mycelimn in the sieve tubes and soft host. This advances most rapidly during the dormant period of the bast. White or yellow stromata the size of a pin- head appear and bear numerous conidia. Later come the red perithecia whose ascospores ripen in winter or spring. N. ribis (Tode) Rab. Fig. 144.—n. ipo- Cespitose, Stroma compact; perithecia sub- of perithecia. globose, smooth; ostiole papillate; asci subclavate, After HaUted. 90-100 x 15; spores elongate or fusoid, hyaline, 1-septate, 18-20 x 5-6 mm. On currant. N. ipomoese Hals. Perithecia clustered, ovate, roughened, red; asci cylindric- clavate; spores elliptic; conidial phase (Fusarium) appearing as a white mold-like covering of the host; conidia several-celled, falcate. Halsted ^* inoculated sterilized egg-plant stems with the Nectria spores and the Fusarium form developed, followed by the asci- gerous stage. Ascospores in hanging drop were also seen to give rise to the Fusarial stage. The Nectrias found upon egg-plant and sweet potato, morphologically alike, were proved by cross inoculations to be identical. N. rousseUiana Tul. and N. pandani Tul. are parasitic on Buxus and Pandanus respectively,*' the former with the conidial stage. Volutella buxi. N. solani Ren. & Bert, is said by Massee to be the ascigerous form of Fusarium solani.** Perithecia crowded on a stroma, minute, conic-globose, smooth, blood-red; asci clavate; spores hyaline, 8-9 x 5 n; paraphyses slender, tips strongly clavate. Conidia (=Fusariiun solani) hyaline, 3 to 5-septate, fusiform, 15-40 x 5-^ fi, but very variable, borne on erect, simple or branched Fig. 145.—n. ipo- COnidiophores. moea, the Fusa- •KT a • 1 rw- num stage. After a. coneicola Zimm. is on cacao and vanilla; Halsted. N. bainii Mas. N. amerunensis A. & Str. and N. diversispora Petch. ar
Size: 1705px × 1465px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectfungi, bookyear1913
