Alginate gel entrapped ectomycorrhizal inoculum promoted growth of cuttings of Eucalyptus clones under nursery conditions

Abstract

Plant inoculation with ectomycorrhizal fungi (EMF) maximizes the productive potential of forest stands. Thus, the inoculation efficiency of calcium alginate gel entrapped EMF vegetative mycelium was evaluated in a commercial nursery using cuttings of Eucalyptus clones GG100 and GG680. The cuttings were inoculated with Pisolithus microcarpus G. Cunn. (Cooke & Massee), Hysterangium gardneri E. Fisch., and Scleroderma areolatum Ehrenb. The cuttings were cultivated under low phosphate fertilization and compared with uninoculated control treatments with reduced phosphate (low P control) and full phosphate (high P control) fertilization. Pisolithus microcarpus inoculation increased shoot height, root collar diameter, shoot dry mass, total dry mass, and frequency of maximum score for root ball formation of the two clones compared with the low P control treatment. Also, in relation to the low P control treatment, H. gardneri inoculation increased shoot dry mass in GG100 rooted cuttings. Scleroderma areolatum inoculation did not enhance any characteristic of Eucalyptus rooted cuttings. Inoculation of vegetative mycelium with EMF impregnated in calcium alginate gel intensified rooted cutting growth in a commercial Eucalyptus nursery and decreased the phosphate dose required. Based on the comparison of two Eucalyptus clones, efficiency of the inoculants in promoting benefits depends on the fungus and the Eucalyptus clone. Pisolithus microcarpus is most promising for inoculation in Eucalyptus cuttings.