Spatio-temporal Soil Water Changes in Fairy-ring Colony of Tricholoma matsutake

摘要

Water is critically important for Tricholoma matsulake(Tm) growth because it is the major component of the mushroom by over 90%. The mushroom absorbs water through the below ground hyphal colony. Therefore, the objectives of our study were to investigate spatio-temporal water changes in Tm colonies. This study was carried out at Tm fruiting sites in Sogni Mt National Park, where the below-ground fairy-ring colonies have been irrigated. To identify spatial water status within the Tm soil colony soilmoisture and ergosterol content were measured at six positions including a mushroom fruiting position on the line of the colony radius. To investigate temporal soil moisture changes in the soil colony, Time Domain Reflectometry(TDR) sensors were established at the non-colony and colony front edge, and water data were recorded with CR10X data logger from late August to late October. Before irrigation, whereas it was 12.8% at non-colony, the soil water content within Tm colony was 8.0% at 0 approx 5cm from the colony front edge, 6.2% at 10 approx 15cm and 6.5 approx 7.5% at 20 approx 40cm. And the content was 12.1% at 80cm distance from the colony edge, which is similar to that at the non-colony. In contrast, ergosterol content which is proportional to the live hyphal biomass was only 0.4 mu g/g fresh soil at the uncolonized soil, while 4.9 mu g/g fresh soil at the front edge where the hyphae actively grow, and 3.8 mu g/g fresh soil at the fruiting position, 1.1 mu g/g at 20cm distance and 0.4 mu g/g inthe 40cm rear area. Generally, in the Tm fungal colony the water content changes were reversed to the ergosterol content changes. While the site was watered during August to October, the soil water contents were 13.5 approx 23.0% within the fungal colony, whereas it was 14.5 approx 26.0% at the non-colony. That is, soil water content in the colony was lower by 1.0 approx 3.0% than that in the non-colonized soil. Our results show that Tm colony consumes more soil water than other parts. Especially the front 30cm within the hyphal colony parts is more critical for soil water absorption.