V. Vilich et al., CHAETOMIUM SPP COLONIZATION OF BARLEY FOLLOWING SEED TREATMENT AND ITS EFFECT ON PLANT-GROWTH AND ERYSIPHE-GRAMINIS F-SP HORDEI DISEASE SEVERITY, Zeitschrift fur Pflanzenkrankheiten und Pflanzenschutz, 105(2), 1998, pp. 130-139
Experiments were carried our to determine the effect of saprophytic fu
ngal endophytes (Chaetomium spp.) on barley (cv. 'Tapir') plans growth
, bacterial colonization of the rhizosphere and in vitro/in vivo inhib
ition of challenged Erysiphe graminis f. sp. hordei. Seed treatments w
ith C. globosum and C. funicola resulted in an increase in root fresh
weight. Shoot fresh weight was not affected. Total bacterial density (
cfu/g on Tryptic-Soy-Agar) of rhizosphere soil was not altered by the
presence of the endophytes. After seed inoculation and 3 weeks of cult
ivation, the fungi were re-isolated initially from the roots and later
fr om the leaves without causing any symptoms. Frequency of endophyte
re-isolation from plant tissue was higher for C.funicola (max. 95 %)
than for C. globosum (max. 44 %). The use of sport suspensions for ino
culation led to better colonization of the tissues as indicated by the
higher re-isolation. rates than alginate pellets. Culture filtrates o
f the fungal endophytes inhibited in vitro the germination of mildew c
onidia on solid media (max. 41 % reduction). Abnormal morphological st
ructures were nor: detected Following exposure to the metabolites. iri
vivo experiments tinder greenhouse condition revealed an antagonistic
effect of C. globosum on powdery mildew development on primary leaves
of barley cv, 'Jana' which is also shown to be colonized by this endo
phyte. Reductions in disease severity varied from 16-48 % compared to
the untreated control. The potential of saprophytic endophytes for pla
nt health purposes is discussed.