title: Damping-off in conifer seedling nurseries in Noshahr and Kelardasht.
abstract: To study the damping-off of conifer seedlings, we have collected samples from the roots of conifer seedlings (Pinus nigra, Picea excelsa, Abieces spp, Cupressus arizonica, Cupressus sempervirens) from nurseries in the south of Iran (Noshahr and Kelardasht). After disinfecting the samples, we have used standard media like PDA, MA and CLA. The following fungi were identified: Fusarium solani, Fusarium oxysporum, Fusarium sambucinum, Clamydosporium, Rhizoctonia solani, Cylindrocarpon spp., Alternaria spp, Macrophomina phaseoli. Amongst the above mentioned fungi, Fusarium spp. were the commonest ones. Pathogenecity tests of Fusarium spp. and Rhizoctonia solani on seedlings were done. Isolated fungal colonies were purified using single mycelium and single spore methods. Fungal isolates were identified after subculturing on PDA and CLA media by Nelson method. These isolates were Fusarium solani, F. oxysporium, F. sambucinum and F. clamydosporum. Other fungal isolates were Rhizoctonia spp. In order to determine the infectivity of Fusarium on their hosts, seeds of Pinus nigra, Cupressus arizonica and Cupressus sempervirens var. horizontalis were cultured in four repetitions each containing 2 seedlings. After a seasonal growth, seedlings were inoculated with a suspension of Fusarium spores (4.5 +/- 0.3 x 1016 spore/ml). Infection of P. nigra, Cupressus arizonica and Cupressus sempervirens var. horizontalis with F. solani and Pinus nigra and Cupressus semperivirens var. horizontalis with F. oxysporum was high whereas that of Cupressus arizonica with F. sambucinum, F. mondiforme and F. clamydosporum was moderate.
authors.affiliation: College of Agriculture, University of Tehran, Tehran, Iran.
authors.forename: S J
authors.initials: SJ
authors.lastname: Zad
authors.forename: M
authors.initials: M
authors.lastname: Koshnevice
mesh_terms: D028202:Abies / Q000254:growth & development / Q000382:microbiology; D029781:Cupressus / Q000254:growth & development / Q000382:microbiology; D005658:Fungi / Q000254:growth & development* / Q000302:isolation & purification / Q000472:pathogenicity; D005670:Fusarium / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity; D007492:Iran; D028223:Pinus / Q000254:growth & development / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology*; D012988:Soil Microbiology; D064028:Tracheophyta / Q000254:growth & development / Q000382:microbiology*