Effects of greenhouse soil sterilization and Glomus mosseae on growth and nutrients absorption of cucumber (Cucumis sativus L.) seedlings

【Objective】To investigate effects of Glomus mosseae and continuous cropping soil sterilization on the growth and nutrients absorption of cucumber seedlings，so as to explore the potential of this fungus in alleviating continuous cropping obstacles.【Method】Jinchun No.3 cucumber was taken as tested variety.A pot experiment was carried out in greenhouse，and 2 factors of continuous cropping soil treatment and G.mosseae were designed according to complete solution to set 4 treatments.For the soil treatments，two levels，sterilization and no sterilization were set.For G.mosseae at nursery stage，two levels，inoculation and no inoculation with G.mosseae，were set.Growth parameters of seedlings，total nitrogen，total phosphorus，total potassium and mycorrhizal infection rate of above-ground parts and other indicators were determined.【Result】Soil sterilization could significantly promote the root growth of cucumber seedlings： When cucumber seedlings were not inoculated with G.mosseae，root vigor and dry weight of seedlings grown on sterilized soil were significantly higher than those of seedlings grown on unsterilized soil（P<0.05，the same below）.Meanwhile，soil sterilization and G.mosseae had synergistic effect:Under condition of unsterilized soi，dry weight of above-ground part，root dry weight and leaf area of cucumber seedlings inoculated with G.mosseae were obviously higher than those of other treatments.Seedling growth was promoted by G.mosseae on sterilized soil，and such result was not only related to the nutrition improvement in above-ground parts，but also related to the significant increase of available nutrient content in sterilized soil.For one，after soil sterilization，the mycorrhizal effect reached 31.4% and total nitrogen，total phosphorus and total potassium in above-ground parts of mycorrhizal seedlings were 1.18，1.33 and 1.31 times higher than those of seedlings that were not inoculated with G.mosseae.Moreover，G.mosseae contributed more than 40.0% to nitrogen，phosphorus and potassium absorption.For another，contents of alkali-hydrolysable nitrogen，available phosphorus and available potassium significantly increased after the soil sterilization；alkaline hydrolysable nitrogen，available phosphorus and available potassium contents were significantly higher than those of unsterilized treatments；alkali-hydrolysable nitrogen，available phosphorus and available potassium contents of sterilized soil were respectively 1.28 times，1.31 times and 1.52 times of unsterilized treatments and pH increased at the same time.【Conclusion】 Alkali-hydrolysable nitrogen，available phosphorus and available potassium contents can be significantly increased by high temperature sterilization.Furthermore，the growth and nitrogen，phosphorus and potassium absorption of Jinchun No.3 cucumber seedlings can be promoted by inoculating with G.mosseae on the sterilized continuous cropping soil.