Comparison of Three Sterilization Methods of Growth Substrates on Mycorrhization of Trifoliate Orange Seedlings

摘要

Mycorrhization of seedlings is a feasible approach for establishing better mycorrhizal development in nursery. The present study compared the effectiveness of three sterilizations (autoclaving, oven, and ultraviolet) of growth substrates on mycorrhization of trifoliate orange (Poncirus trifoliata) seedlings, in terms of mycorrhiza, plant growth, root system architecture (RSA), leaf chlorophyll and carbohydrates. The sterilizations obviously inhibited mycorrhizal colonization, entry points and arbuscules, significantly restricted plant growth (plant height, stem diameter, leaf number, fresh and dry weights of shoot and root) and RSA (length, projected area, surface area, volumn, and number of tips, crossings and forks), decreased leaf chlorophyll concentration, and reduced glucose concentrations of leaf and root, as compared with the non-sterilization control. The restricted extent was as follows: autoclaving > oven > ultraviolet. It concludes that the sterilizations might kill many spores of native AMF in growth substrates, thus resulting in the decreases of growth, RSA, chlorophyll and glucose. At the time of mycorrhization of trifoliate orange seedlings, the sterilizations of growth substrates can select the order of autoclaving > oven > ultraviolet.