. Cronartium comandrae in the Rocky Mountain States. Cronartium comandrae Rocky Mountains Region; Fungi Rocky Mountains Region. INFECTION Comandra, jack pine, ponderosa pine, and lodgepole pine have previously been infected with comandra rust in experimental trials (Adams 1919, Anderson 1960, Andrews et al. 1963, and Hedgcock and Long 1915). However, virtually nothing is reported about the processes of infection or the influ- ence of moisture, temperature, or host phenology on infection. Some information on these factors was obtained in the following trials. COMANDRA of infection spots (eviden
. Cronartium comandrae in the Rocky Mountain States. Cronartium comandrae Rocky Mountains Region; Fungi Rocky Mountains Region. INFECTION Comandra, jack pine, ponderosa pine, and lodgepole pine have previously been infected with comandra rust in experimental trials (Adams 1919, Anderson 1960, Andrews et al. 1963, and Hedgcock and Long 1915). However, virtually nothing is reported about the processes of infection or the influ- ence of moisture, temperature, or host phenology on infection. Some information on these factors was obtained in the following trials. COMANDRA of infection spots (evidenced by yellow color, swell- ing, and uredinia) on test shoots were counted. Infection of comandra occurred over a wide range of temperatures with both aeciospore and urediniospore inoculum (table 9). Although infection spots increased with longer mist periods, 12 to 24 hours was sufficient for abundant infection at mod- erate temperatures. In foUowup trials, infection occurred in as Uttle as 5 hours in a mist chamber at about 20° C. Penetration of comandra was observed with an incident light microscope and with a normal Ught microscope when leaves were cleared by the lactophenol-chloral hydrate technique (Riker and Riker 1936) and stained with aniline blue. Both aeciospores and urediniospores germinated well on leaf surfaces. Appressoria formed when germ tubes contacted stomates (fig. 13), and infection pegs could be seen penetrating between the guard cells of stomates. This was the only type of penetration seen in comandra. The influence of temperature during inocu- lation of comandra was studied under controlled con- ditions. Comandra that had been growing in flats in Logan for at least a year were used as test plants. At the time of inoculation, shoots were about 2 months old. Inoculum consisted of fresh aeciospores and urediniospores originating in Cache National Forest. Approximately equal numbers of spores were depos- ited on test shoots by the settling tower method desc
Size: 1537px × 1625px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
