Impact of water potential on growth and germination of Fusarium solani soilborne pathogen of peanut

Studies were conducted to determine the effect of osmotic and matric stress on germination and growth of two Fusarium solani strains, the etiological agent responsible of peanut brown root rot. Both strains had similar osmotic and matric potential ranges that allowed growth, being the latter one narrower. F. solani showed the ability to grow down to -14 MPa at 25 °C in non-ionic modified osmotic medium, while under matric stress this was limited to -8.4 MPa at 25 °C. However, both strains were seen to respond differently to decreasing osmotic and matric potentials, during early stages of germination. One strain (RC 338) showed to be more sensitive to matric than osmotic (non ionic) and the other one (RC 386) showed to be more sensitive to osmotic than matric imposed water stress. After 24 h of incubation, both isolates behaved similarly. The minimum water potential for germination was -8.4 MPa on glycerol amended media and -5.6 MPa for NaCl and PEG amended media, respectively. The knowledge of the water potential range which allow mycelia growth and spore germination of F. solani provides an inside to the likely behaviour of this devastating soilborne plant pathogen in nature and has important practical implications.

Attenuation of radiosensitivity in trichoderma viride through culturing on extracts of more radioresistant fungal sp

The response of Trichoderma viride and Fusarium moniliforme to gamma radiation was investigated. Trichoderma viride was sensitive and a dose of 2.0 KGy was lethal, while F. Moniliforme was resistant to doses up to 4.0 KGy. Inoculation of Trichoderma viride conidia on media amended with extracts from F. moniliforme cultures as well as filtrate produced more radioresistant cultures of Trichoderma. So, it could be suggested that the mycelial cells of Fusarium contained endogenous compounds [s] which were responsible for radioresistance