Abstract
Seedlings of winter rye collected from yellowing patches during October to November 1985—1987 showed oospores of Pythium species in apparently healthy as well as in discolored roots. Examination of 1550 root pieces of rye on CMA yielded fungi belonging to 35 genera. The most commonly isolated ones were Fusarium spp, Penicillium spp, Mucor spp, Mortierella spp. and Cladosporium spp. Pythium spp. were isolated from 35 root pieces on CMA. Identified species were P. splendens, P. irregulare, P. dissimile, a species resembling P. aristosporum and a species resembling P. ultimum. In in vitro and in vivo, tests on the cereals winter rye, spring wheat, oats and barley the pathogenicity of some Pythium isolates varied from high (P. splendens, P. irregulare) to moderate (P. irregulare, P. dissimile) and low (a species resembling P. ultimum).
Highlights
Pythium species are common in agricultural soils and they parasitize a wide range of hosts (Domsch et al 1980)
Surface sterilized seeds (1 min in 1 % NaOCl) were pregerminated for five days at room temperature until the seedling was approx. 4 cm long; long seedlings were thereafter planted into white plastic pots (3 dl, 5.5 cm deep) at a depth of 2 cm, five in each
Pathogenicity of Pythium strains in vivo Isolate P 9 significantly decreased shoot dry weight, while the isolates P 2 and Pl 7 (P. irregulare) caused an increase as compared to the control
Summary
Pythium species are common in agricultural soils and they parasitize a wide range of hosts (Domsch et al 1980). All spring and winter small grains and forage grasses are susceptible to root rot caused by one or several Pythium species acting singly or in combination (Wiese 1977). Root rot on rye caused by species of Pythium has been reported only in a few cases. The species Pythium aphanidermatum (Edson) Fitz (Sechler & Luke 1967) and P. myriotylum Drechs. 1970, Mitchell 1975) have caused seedling damping-off and root rot in the southern parts of the U.S.A. Several species of Pythium cause a browning root rot in barley. The disease has been encountered in the U.S.A. P. arrhenomanes Drechs., P. aphanidermatum, P. graminicola
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
