IMPACT OF OSMOTIC AND MATRIC WATER STRESS GROWTH IN FUSARIUM SOLANI ETIOLOGICAL AGENT OF PEANUT BROWN ROOT ROT IN ARGENTINA

REYNOSO M.M.; MEZA, L; CASASNOVAS, F.; RAMIREZ, M.L.; CHULZE, S,N,; TORRES, A.M.

Alghero, Italia

Workshop; X International Fusarium Workshop and Fusarium Genomics Workshop 2008; 2008

Peanut brown root rot caused by species within Fusarium solani species complex is an important disease in peanut in Argentina. The main impact of the disease is observed under periods of drought stress. Few data on ecophysiological characterists on the etiological agent are available. The present study was conducted to determine the effect of osmotic (NaCl, glycerol) and matric (PEG8000) water stress on growth of two Fusarium solani strains, over the water potential range of  0.7 to 14.0 MPa at 18 and 25º C. The maximum growth rates were obtained at 0.7 MPa and 25º C on osmotically (ionic and non-ionic) amended medium. On the matrically modified media, maximun growth rates were also obtained at 0.7 MPat 25º C, but were lower than those obtained on osmotically modified media. Similar behavior was observed at 18º C. The results obtained suggest that F. solani mycelial extension is more sensitive to matric than osmotic potential stress. Also this study enables a better understanding of the survival and growth strategy employed by F. solani for survival, growth and establishment in natural ecosystems.