S. M. Taghavi, M. Ziaee,
Volume 7, Issue 1 (4-2003)
Abstract
In order to compare Pseudomonas syringae pv. syringae (Pss) isolates from cereals, citrus, stone fruits and weeds by phenotypic characteristics, serological properties and pathogenicity, samples were taken during 1998-1999 in Fars Province, Karaj, Fereidan, Aligudarz and Shahrekord regions. From 350 fluorescent isolates, 47 were negative with respect to oxidase, potato soft rot and arginine dihydrolase tests but positive in hypersensitive reaction (HR) on tobacco, pelargonium, or both. In complementary biochemical tests, these isolates were identified as Pss. Based on LOPAT (levan, oxidase, potato soft rot, arginine dihydrolase and HR on tobacco leaves) tests, the isolates were divided into two groups, but based on the results of GATTa tests alone, isolates were divided into nine groups. Isolates from different hosts showed differences in lipolysis, syringomycin production, ice nucleation activity, lecithinase, pathogenicity, serology and protein profiles.
R. Mohammadi, A. F. Mirlohi,
Volume 7, Issue 2 (7-2003)
Abstract
A symbiotic relationship exists between the endophytic fungi of the genus Neotyphodium and many cool-season grasses. Endophytes can alter the growth as well as morphological and physiological characteristics of the host plant, thereby influencing the persistence and survival rate of infected plants. This study was conducted to evaluate the effects of endophyte on phenotypic characteristics of Iranian tall fescue (Festuca arundinacea Schreb.) and meadow fescue (Festuca pratensis Huds.). The experiment was set up as a completely randomized design with three replications in a factorial arrangement. The first factor was the two plant accessions and the secondary factor was the endophyte-infected and noninfected plants. The results showed that most of phenotypic characteristics significantly altered as a result of endophyte infection in both tall fescue and meadow fescue plants. Results of analysis of variance showed that the influence of endophyte fungus was positive and significant on tiller number, herbage yield, dry crown weight, dry root weight per plant, and crown depth. Also between plant accessions, there were significant differences for dry herbage yield, crown weight, dry root weight per plant, crown depth, and dry matter percentage. Plant by endophyte interaction was highly significant for crown depth and dry root weight per plant. Therefore, eudophytic fungi can be used to improve phenotypic characteristics in these plants.
