降香黄檀土壤微生物数量的时空动态特征

【目的】研究降香黄檀土壤微生物数量在时间和空间上的动态特征,可为降香黄檀栽培技术的完善提供数据支持。【方法】采用稀释平板涂布法,比较分析降香黄檀根际和非根际土壤微生物三大类群(细菌、放线菌、真菌)数量的季节及垂直分布情况。【结果】(1)降香黄檀根际和非根际土壤均表现为春季细菌、真菌数量较多,冬季细菌数量较少,秋季真菌数量较少;非根际土壤放线菌冬季数量较多,秋季数量较少。(2)细菌的根际效应最为明显,其R/S为0.12~62.96;真菌次之,其R/S为0.22~2.46;放线菌的根际效应较小,其R/S为0.32~1.01。(3)降香黄檀上层土(0~20 cm)的微生物数量普遍高于其他土层;随着土层加深,微生物数量表现为逐渐下降或先下降后升高2种变化趋势。【结论】降香黄檀土壤微生物数量的分布受季节和土层的影响。

Spatiotemporal characteristics of soil microbial communities associated with rosewood,Dalbergia odorifera

[Aim] We studied the spatiotemporal characteristics for number of soil microorganism of Dalbergia odorifera so as to provide basis for improvement of cultivation technology of D. odorifera.[Method] Using the dilution plate coating method, seasonal and vertical distribution of the soil microbial community (bacteria, actinomycetes and fungi) in the rhizosphere and non-rhizosphere soil around D. odorifera individuals were compared.[Results] (1) The number of bacteria and fungi in the soil were the highest in spring. The lowest number of bacteria was found during winter, while the number of fungi was the lowest during autumn. The number of non-rhizosphere actinomycetes was the highest in winter and the lowest in autumn. (2) Rhizosphere effect of bacteria was more obvious, their R/S being 0.12-62.96, followed by the fungi with an R/S of 0.22-2.46, and of actinomycetes, with an R/S of 0.32-1.01. (3) The numbers of soil microorganisms were higher in the top soil layer (0-20 cm) than in deeper soil layers. The numbers of soil microorganism gradually decreased with depth; in some cases, however, the first decrease was followed by an increase.[Conclusion] The number distribution of soil microbial community of D. odorifera is influenced by season and soil layer.