厦门市七种药用植物根围AM真菌的侵染率和多样性

王明元 Wang Mingyuan,姜攀 Jiang Pan

doi:10.5846/stxb201106030745

Abstract

调查了福建省厦门市7种常见药用植物根围丛枝菌根真菌分布情况、侵染率及其多样性。结果表明:7种药用植物均能与AM真菌形成良好的共生关系,且不同药用植物形成菌根的能力差异明显,盐肤木根围的孢子密度最高,29.0 个/g土,喜树的侵染率最高,100%。含笑根围的孢子密度最低,4.7 个/g土,鱼腥草的总侵染率最低,4.5%。共分离鉴定AM真菌4属63种,其中球囊霉属(Glomus)39种、无梗囊霉属(Acaulospora)18种、巨孢囊霉属(Gigaspora)4种、盾巨孢囊霉属(Scutellospora)2种,其中Glomus、Acaulospora为优势属,黑球囊霉G. melanosporum为优势种。盐肤木根围AM真菌种类最丰富,Shannon-Weiner指数H达到1.29。侵染率与各土壤因子均无显著相关;孢子密度与pH值极显著负相关;种的丰度与pH值显著负相关、与电导率极显著负相关、与孢子密度极显著正相关;Shannon-Weiner指数H与有机质极显著负相关;均匀度与有机质、孢子密度极显著负相关。厦门地区AM真菌资源十分丰富,多样性程度高,宿主植物不同,土壤因子对其侵染率、孢子密度、种的丰度、Shannon-Weiner指数、均匀度的影响也不同。为实现AM真菌生物技术应用于中药材规范化种植提供宝贵种质资源和理论依据。;The distribution, colonization rate and diversity of arbuscular mycorrhizal (AM) fungi in the rhizosphere of seven medicinal plants species in Xiamen, Fujian province were studied. The spores of AM fungi were isolated by modified method of wet sieving and decanting technique and identifled based on spore morphology and subcellular characters. The results showed a strong symbiotic relationship between seven medicinal plants and AM fungi. The highest spore density (29.0 cfu per g soil) was found in Rhus chinensis while the lowest (4.7 cfu per g soil) was in Michelia figo. Spores of Gigaspora occurred rarely and only in Houttuynia cordata Thunb., and Scutellospora only in Rosa laevigata Michx. Glomus melanosporum was most frequently associated with the 7 medicinal plants species. The highest mycorrhizal colonization (100%) was recorded in Camptotheca acuminata Decne while the lowest (4.5%) was in Houttuynia cordata Thunb. The results indicated that sixty three species of four genera of AM fungi were isolated, of which thirty-nine belonged to Glomus, eighteen to Acaulospora, two to Scutellospora and four to Gigaspora. Meanwhile, Glomus and Acaulospora were the dominant genera of the seven medicinal plants and G. melanosporum, A. excavata, G. ambisporum, G. clarum, and G. geosporum were the prevalent AM fungi. The highest species richness (26), Shannon-Wiener index (H) (2.29), and evenness (0.83) were found in Rhus chinensis, Rosa laevigata Michx., and Mirabilis jalapa Linn., in contrast to the lowest one in Houttuynia cordata Thunb.(9), Houttuynia cordata Thunb.(1.06) and Rhus chinensis.(0.39). The frequency (F) and importance value (I) of Glomus and Acaulospora in all the plants were higher than 50 percent. As the soil characteristic may play an important role in the ecological distribution of AM fungi, available P, available K, available N, organic matter, pH and electrical conductivity of the soil samples were investigated. In the present study, the colonization had no significant correlation with the soil factors. Spore density had a highly significantly negative correlation with pH values (P＜0.01). Species richness correlated significantly negatively with pH (P＜0.05), and had a highly significantly negative correlation with electrical conductivity, while highly positive correlation with spore density (P＜0.01). Shannon-Wiener index (H) had a highly significantly negative correlation with organic matter (P＜0.01). Evenness had a highly significantly negative correlations with soil organic matter and spore density (P＜0.01). These results indicated a high diversity of AM fungi in Xiamen. The effects of soil factors on colonization rate, spore density, species richness, Shannon-Wiener index (H) and evenness all varied with host plants. The colonization rate, spore density and species richness had negative correlations with pH values, available P, available N and electrical conductivity. The colonization rate and Shannon-Wiener index (H) had positive correlation with available K and evenness had positive correlation with available K, organic matter, pH and electrical conductivity. AM fungi may be a potent biological resource which can stimulate the growth of medicinal plants. This study provids a valuable germplasm and theoretical basis for AM fungal biotechnology to apply to medicinal standardization on planting.

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