EFFECT OF ADDING CARROT, DAUCUS-CAROTA VARIETY SATIVA, TO MEDIA IN THE RHIZOMORPH PRODUCTION OF ARMILLARIA SPECIES

Rhizomorph production of Armillaria spp. was stimulated by adding carrot (Daucus carota L. var. sativa DC.) and it's hot-water extract to media. Rhizomorph production of 23 isolates, collected in Hokkaido Prefecture, was assayed on three kinds of nutrient agar media, a control medium (glucose: 10 g, malt extract: 10 g, yeast extract: 3 g, agar: 15 g, tag water: 1,000 ml), a carrot medium which was the same as the control medium supplied with the extract instead of tap water and an ethanol medium which was supplemented with 99.5% (v/v) ethanol (20 ml) in the control medium. Seventeen and 21 isolates tested were stimulated rhizomorph production on the carrot and the ethanol media, respectively, on the basis of rhizomorph production time in comparison with the control medium. Further more, rhizomorph growth of 23 isolates was stimulated on the carrot and the ethanol media. Dry weights of mycelium containing rhizomorph were larger on two media than on the control medium. Ratios of the weights to control were from 1.09 to 2.06 on the carrot medium and from 1.01 to 3.12 on the ethanol medium. On the other hand, rhizomorph production of two isolates, HFP-Am 82-10 and HFP-Am 82-14 which were suitable for artificial cultivation and belonged to the above 17 isolates, were tested on sawdust medium. Incubation periods taken to produce results in the production of rhizomorph from spawns after inoculation were 6.2 days on the former and 8.2 days on the latter at 22-degrees-C and 70% humidity in the dark. By interposing carrot, ground and autoclaved between the spawn and the medium, the incubation periods were reduced to 4.3 and 4.7 days, respectively. In addition, incubation periods after inoculation to fulfillment of mycelium on the media were shortened 13.1% on HFP-Am 82-10 and 6.0% on HFP-Am 82-14 in comparison with no interposing carrot. Moreover, the yield, the yield pattern and the quality of fruiting bodies were not affected by using carrot.