Ectomycorrhizal inoculum viability for Nothofagus species from the Patagonian forest of Argentina.

BASSANI V.M., C. BARROETAVEÑA, M. RAJCHENBERG

Belo Horizonte Brasil

Congreso; 6 International Congress of Mycorrhiza; 2009

International Mycorrhiza society

The increasing concern to recover degraded areas of Nothofagus spp. forests poses the challenge to produce ectomycorrhizal seedlings prepared to survive under unfavorable conditions. Starting an inoculation program requires selecting the best fungal species, adjusting the technology of inoculum conservancy and running nursery inoculation trials. To do that, species of ECM fungi were classified according to their aptitude to be used as spore inoculums, and their conservation tested. Taxa were classified according to the ease to be found, abundance, frequency of occurrence and spore density. 6 ECM species where selected and stored at 5ºC as spore slurries and dried sporocaps with 4 repetitions each. Viability was measured along 270 days using Thiazolyl Blue Tetrazolium Bromide.  Cortinarius xiphidipus and Thaxtherogaster sp.nov. had 3200 and 3492 spores/mm3, Austropaxillus statumm and Setchelliogaster fragilis 5820 and 6060 spores/mm3 and H. purpurea 27046 spores/mm3. After 270 days Thaxtherogaster sp.nov, C. xiphidipus and S. fragilis showed the highest viability as slurries (25.9, 19.1 and 18.8 % viable spores) while S. fragilis and A. statuum had better values conserved dried (26.3 and 21.6 % viable spores). Hallingea purpureus showed a drastic viability loss under both methods (8-11 % at 270 days). Better inoculum conservation method seems to depend on species. A. statumm and S. fragilis presented the better combination of characteristics to be used for inoculations.