Inoculation of eucalyptus urophylla with spores of Scleroderma in a nursery in south China: Comparison of field soil and potting mix

Non-pasteurized soil or soil-based rooting media are being used to raise eucalypts in nurseries in south China. It is unclear whether these practices are optimal for the growth of eucalypt plants or the development of ectomycorrhizal associations. Therefore, there is a need to optimize nursery practices to meet the demand for high quality seedlings and clonal lines of Eucalyptus urophylla and hybrids, for outplanting in the region. Inoculation with spores of ectomycorrhizal fungi is accepted as desirable due to potential yield benefits in the field. Previous studies have shown that spores of some collections of Scleroderma are vigorous colonizers on E. urophylla seedlings. These could be used in inoculation programs in China if nursery conditions were suitable for ectomycorrhizal development and the fungi persisted in the field. Therefore, effects of rooting medium and inoculation with Scleroderma on the growth of E. urophylla were examined in a nursery in south China. A complete randomized block design consisting of five rooting media and eight fungal inoculation (six fungi in non-sterile media, two uninoculated controls either in non-sterile or sterile media) was used. Four types of soil taken from eucalypt plantations in south China were compared to a potting mix with vermiculite, peat and sand. Spores of six Scleroderma taxa were taken from basidiomes collected from under eucalypt plantations in Western Australia and south China. Soil substrates significantly affected the growth of seedlings with large variation in both height and biomass. Seedlings grown in the potting mix were larger (90–220% in shoot height, and 110–420% in total dry weight) than those in soil. Inoculation with spores of Scleroderma to non-sterile soil generally promoted the growth of seedlings and their nutrient acquisition. Inoculation increased the growth of seedlings by 19–55% in shoot height and 25–41% in total biomass, compared to uninoculated plants in each soil. Although the ability t