Decomposition of canola stubble by solid-state fermentation with Cyathus olla.

Cyathus olla is being studied for its potential as an inoculant to accelera te decomposition of canola stubble, and hence to reduce the incidence of st ubble-borne diseases of this crop. Stubble infested by C. olla appears soft and macerated, but the extent of decomposition incited by th is fungus is not known. Composition of stubble fiber of five canola cultivars was determ ined with the Goering Van Soest method of fiber determination. Sterile cano la (cv. Cyclone) substrate was inoculated with C. olla and incubated at 25 degreesC for 45 days, followed by fiber analyses to detect changes in the f iber content. All cultivars were variable with respect to cell wall composi tion. Canola substrate inoculated with C. olla f. brodiensis had 60.6% of t he original lignin remaining after incubation, compared to 65.9% for the su bstrate incubated with C. olla f. olla and 71.8% with C. olla f. anglicus. Hemicellulose content was reduced as only 75.3, 78.6, and 81.6% of the orig inal hemicellulose content remained after incubation with C. olla f, brodie nsis, C. olla f. olla, and C. olla f. anglicus, respectively. Cellulose was also degraded, and the neutral detergent soluble fraction increased. Cyath us olla was capable of degrading lignin in vitro, but field testing must fo llow to assess its decomposing activity under natural conditions.