沿海造林树种根际丛枝菌根真菌与土壤因子的通径分析

Path analysis of arbuscular mycorrhizal fungi and soil factors in coastal afforestation tree species

【目的】探讨苏北沿海土壤理化性质对当地主要造林树种根际丛枝菌根真菌(AMF)侵染及球囊霉相关蛋白数量的影响,为丛枝菌根真菌在沿海困难立地造林提供理论依据。【方法】以江苏盐城大丰林场内的8个不同树种为研究对象(薄壳山核桃、杨树、水杉、榉树、中山杉、杜仲、银杏、胡颓子),测定土壤理化性质,根据通径分析,探讨造林树种根际丛枝菌根真菌与土壤因子的关系。【结果】丛枝菌根真菌(AMF)侵染率最高为薄壳山核桃,最低为银杏;孢子密度最高为杜仲,最低为银杏;总球囊霉素最高为榉树,最低为中山杉;易提取球囊霉素最高为杨树,最低为银杏。AMF侵染率与土壤全磷含量呈极显著负相关(P<0.01);总球囊霉素与pH呈极显著负相关(P<0.01),与速效钾和有机碳呈极显著正相关(P<0.01);易提取球囊霉素与土壤全钠含量呈极显著正相关(P<0.01),与土壤全磷呈显著负相关(P<0.05);孢子密度与土壤因子并无显著性关系。通径分析显示,土壤全磷对AMF侵染率直接作用最强,土壤全钾、电导率的作用次之;土壤速效钾对总球囊霉素的直接作用最强,pH、可溶性有机碳、全钠、电导率的作用次之,硝态氮对总球囊霉素含量的影响表现在间接作用上;全钠对易提取球囊霉素的直接作用最强,电导率、全磷的作用次之,全钾对易提取球囊霉素的影响表现在间接作用上。【结论】沿海地区生长的8个树种均检测到AMF侵染,且土壤因子对AMF与树种的互利共生关系有显著影响。

【Objective】The research was conducted to analysis the effects of soil physical and chemical properties on arbuscular mycorrhizal fungi(AMF) and glomalin-related proteins in the rhizosphere soil of afforestation tree species in coastal area of Jiangsu Province, which provided a theoretical support for AMF application in afforestation of coastal area.【Method】Eight different tree species [Carya illinoensis(Wangenh.) K. Koch, Populus lasiocarpa Oliv, Metasequoia glyptostroboides Hu et Cheng, Zelkova serrata(Thunb.) Makinoz, Taxodium ‘Zhongshanshan’, Eucommia ulmoides Oliv, Ginkgo biloba Linn, Elaeagnus pungens Thunb.] of Dafeng Forest Farm were selected as objects. We certificated the relationship between AMF and soil factors based on redundancy and path analysis.【Result】 The highest colonization of AMF was C. illinoensis and the lowest was G. biloba;the highest spore density was E. ulmoides and the lowest was G. biloba. The highest content of total glomalin-related soil protein(T-GRSP) was Z. serrata and the lowest was T.‘Zhongshanshan’;the highest content easily extractable glomalin-related soil protein(EE-GRSP) was P. lasiocarpa and the lowest was G. biloba. There was a negative correlation between AMF colonization and soil total phosphorus content significantly(P<0.01). The T-GRSP was significant and negative correlation with soil pH(P<0.01), positive correlation with available potassium(P<0.01) and organic carbon in soil(P<0.01). EE-GRSP was positive correlation with total sodium(P<0.01) and negative correlation with total phosphorus content(P<0.05). There was no significant relationship between spore density and soil factors. The results of path analysis showed that soil total phosphorus had the strongest direct effect on AMF colonization rate and soil total potassium, soil conductivity was followed. Soil available potassium had the strongest direct effect on T-GRSP content, and soil pH, soluble organic carbon, total sodium, conductivity were followed;the nitrate nitrogen on T-GRSP content was showed the indirect effect. The direct role of total sodium on EE-GRSP was the strongest, the conductivity and total phosphorus were the second. And the indirect effect on EE-GRSP was total potassium.【Conclusion】AMF colonization was detected in 8 tree species and soil factors had a significant effect on the mutual symbiotic relationship between AMF and tree species.