关键词: 菌根, 马尾松, 苗木, 根际土壤浸提物, 种子萌发, 化感效应

Abstract: [Objective] This study aims to investigate the effects from ectotrophic mycorrhiza on the variety and content of the extracts from rhizospheric soil of Pinus massoniana seedlings, and elucidate the effect of soil extracts on seed germination and provides scientific basis and theoretical guidance on mycorrhizal seedlings and natural regeneration.[Method] One-year-old Pinus massoniana seedlings, inoculated ones with ECM fungi and uninoculated ones, were used to collect the rhizopheric soil extracts. Ethanol and methanol extracts were used to extract and inoculate the rhizosphere soils of the seedlings. and gas chromatography-mass spectrometry techniques was used in material identification. The variety and contents of the extracts from rhizospheric soil of different Pinus massoniana seedlings were studied, and allelopathic effects from soil extracts to seeds were also studied with bioassay method.[Result] The rhizospheric soil extracts (extracted with ethanol) of Pinus massoniana seedlings inoculated with ECM fungal strain Sl12 and Sl13 had 22 and 23 more components than those of non-mycorrhizal seedlings, respectively. Acids comprised the most abundance components of soil extracts, and accounted for 51.20%, 48.80%, and 34.17% of all detected components of mycorrhizal seedlings inoculated with Sl12 and Sl13 and non-mycorrhizal seedlings, respectively. Using methanol as the solvent, 34, 32, and 23 components were detected from the rhizospheric soil of Sl12, Sl13 and non-mycorrhizal seedlings, respectively. Acids and esters were the most abundant components of the soil extracts. Acids comprised 39.06%, 34.86%, and 33.96%, and esters comprised 32.01%, 38.91% and 35.95% of the total components of Sl12, Sl13 and non-mycorrhizal seedlings, respectively. Palmitic acid, stearic acid and 2,4-2 tertiary butyl phenol were always detected in the rhizosphere of mycorrhizal seedlings, irrelevant to the solvents; only palmitic acid was detected with non-mycorrhizal seedlings. The soil extracts (using ethanol as the solvent) of mycorrhizal seedling rhizosphere had inhibitory effects on seed germination, vigor index, hypocotyl and radical length of P. massoniana.[Conclusion] ECM fungi reconstructed the rhizosphere through altering the profiles of rhizospheric soil extracts, and increased the types and amounts. Three kinds of seedlings of soil extracts from rhizosphere all had inhibitory effect on seed germination.

Key words: mycorrhization, Pinus massoniana, seedlings, rhizospheric soil extracts, seed germination, allelopathy