Parasitism of macroconidia, chlamydospores and hyphae of Fusarium culmorum by mycoparasitic Pythium species

Abstract

Parasitism of macroconidia and endoconidial chlamydospores of Fusarium culmorum by Pythium oligandrum was studied on water agar (WA), corn-meal agar (CMA) and glass slides. Loss of cytoplasmic content in F. culmorum spores was followed by complete degradation, and P. oligandrum produced an abundance of oogonia on the parasitized macroconidia. A simple method for assessing the relative aggressiveness of isolates is presented, based on the percentage of macroconidial cells devoid of cytoplasm. Parasitism of macroconidia by P. acanthophoron, P. oligandrum and P. periplocum, but not by the plant pathogenic species, P. tracheiphilum, was demonstrated by this method. Interactions between hyphae of P. oligandrum and F. culmorum on WA resulted in an increase in the number of oogonia of P. oligandrum and a decrease in the sporulation of F. culmorum. The ability of isolates of P. oligandrum, P. periplocum, P. acanthophoron and P. mycoparasiticum to suppress disease symptoms caused by F. culmorum on barley seedlings was demonstrated in a greenhouse test.

Biological control of one species belonging to the dominant mycobiota of rice of Valencia

“…In different studies, the antagonist Clonostachys rosea reduced and suppressed conidia of Botrytis cinerea (Sutton et al, 1997;Morandi et al, 2003). This behaviour was also observed when mycoparasitic Pythium oligandrum was confronted against Fusarium culmorum in dual culture (Davanlou et al, 1999). Studies of dual cultures of T. harzianum and other species revealed inhibition of germination but no suppression of conidia (Lorito et al, 1993a(Lorito et al, , 1993bZimand et al, 1996;Kapat et al, 1998;Golam Mortuza and Ilag, 1999).…”

“…Previously the authors investigated other interactions and all studies confirmed this technique. There are few researches and the usual techniques to study fungal relations are tedious SEM preparations or light microscopical observations (Madi et al, 1997;Davanlou et al, 1999;Moussa, 2002;Zadworny et al, 2004).…”

Management of Collar Rot of Chickpea (Cicer Arietinum) by Trichoderma Harzianum and Plant Growth Promoting Rhizobacteria

“…Trichoderma harzianum is an effective biocontrol agent which mycoparasitized on Sclerotium rolfsii, Rhizoctonia solani and Pythium aphanidermatum (Elad et al 1980(Elad et al , 1983Sivan et al 1984;Benhamou and Chet 1996;Chet 1987Chet , 1990. The process involved in mycoparasitism may consist of sensing the host, followed by directed growth, contact, recognition, attachment, penetration, and exit (Chet et al 1981;Benhamou et al 1999;Davanlou et al 1999).…”

Efficacy of Trichoderma harzianum in suppression of Fusarium culmorum

“…Also, Phytium species are mycoparasites of this pathogen fungus, and attach to its hyphae, macroconidia and chlamidosphores (Foley and Deacon 1985;Hockenhull 1996, Laing andDeacon 1991). Davanlou et al (1999) showed that the initial contact between P. oligandrum and macroconidia of F. culmorum was followed by coagulation, lost of cytoplasmatic content and degradation of its cell wall.…”