东寨港红树林丛枝菌根真菌侵染和孢子密度及其影响因子研究

丛枝菌根(AM)结构存在于多种红树植物根内,但目前对于红树林中AM真菌的研究还未能完全揭示其存在的原因和状况。研究通过对海南东寨港红树林中不同潮位16种红树植物根内AM侵染情况、AM真菌孢子密度以及土壤理化因子开展调查,以了解东寨港红树林中AM真菌的存在状况及其影响因素。结果表明12种红树植物与AM真菌存在共生关系,其中海漆(Excoecaria agallocha)、许树(Clerodendrum inerme)、水黄皮(Pongamia pinnata)和黄槿(Hibiscus tiliaceus)侵染率较高,均高于55%;16种植物根际土壤中均检测到AM真菌孢子,每25 g土壤的平均孢子密度为(25.7±2.7)个。方差分析表明,不同宿主植物根内AM侵染情况差异显著;潮位对AM侵染率和孢子密度均具有显著影响,表现为高潮位显著高于中、低潮位,而中低潮位间无显著差异。线性回归分析表明土壤含水率、电导率和有效磷含量可能是影响东寨港红树林生境中AM侵染率和孢子密度的主要土壤因子。

Arbuscular Mycorrhizal Fungi Colonization and Spore Density in Mangrove Species and Their Influence Factors in Dongzhaigang Nature Reserve

Arbuscular mycorrhizal (AM) fungi exist in the root of a variety of mangrove plants, but our current research has failed to explain the reason and situation of their existence. This study intended to explore the AM fungi status and their influencing factors in mangrove species in Dongzhaigang National Nature Reserve. 16 mangrove species were investigated for their AM colonization rate, rhizosphere soil AM fungi spore density and soil parameters. The results showed that 12 of the total 16 plant species existed AM colonization, among which Excoecaria agallocha, Clerodendrum inerme, Pongamia pinnata and Hibiscus tiliaceus showed higher colonization rate than others (above 55%). AM fungi spores were detected from all rhizosphere soil samples, and the average AM fungi spore density was 25.7±2.7 spores per 25 g air dried soil. One-way analysis of variance (ANOVA) revealed that AM colonization status was significantly different among different host plants. Tide level could also significantly influence AM colonization rate and spore density. Both AM colonization rate and spore density were significantly higher in high tide level than middle or low tide level, but no difference existed between middle and low tide level. Linear regression analysis showed that soil moisture content, electrical conductivity and available P content may be the main influencing soil factors of AM fungi in Dongzhaigang mangrove ecosystem.