The United Graduate School of Agricultural Sciences, Tottori University, Japan.
Microbes Environ. 2013;28(1):105-11. doi: 10.1264/jsme2.me12118. Epub 2012 Dec 19.
We examined the colonization rate and communities of arbuscular mycorrhizal fungi (AMF) in the roots of Pyrus pyrifolia var. culta (Japanese pear) in orchards to investigate the effect of phosphorus (P) fertilization on AMF. Soil cores containing the roots of Japanese pear were collected from 13 orchards in Tottori Prefecture, Japan. Soil-available P in the examined orchards was 75.7 to 1,200 mg kg(-1), showing the extreme accumulation of soil P in many orchards. The AMF colonization rate was negatively correlated with soil-available P (P <0.01). AMF communities were examined on the basis of the partial fungal DNA sequences of the nuclear small-subunit ribosomal RNA gene (SSU rDNA) amplified by AMF-specific primers AML1 and AML2. The obtained AMF sequences were divided into 14 phylotypes, and the number of phylotypes (species richness) was also negatively correlated with soil-available P (P <0.05). It was also suggested that some AM fungi may be adapted to high soil-available P conditions. Redundancy analysis showed the significant effects of soil pH, available P in soil, and P content in leaves of P. pyrifolia var. culta trees on AMF distribution. These results suggested that the accumulation of soil-available P affected AMF communities in the roots of Japanese pear in the orchard environment.
我们研究了果园中 culta 梨（日本梨）根系中丛枝菌根真菌（AMF）的定植率和群落，以调查磷（P）施肥对 AMF 的影响。从日本鸟取县的 13 个果园中采集了含有 culta 梨根系的土壤芯。研究果园中的土壤有效磷含量为 75.7 至 1200 mg kg(-1)，表明许多果园土壤中磷的积累量极高。AMF 的定植率与土壤有效磷呈负相关（P <0.01）。根据 AMF 特异性引物 AML1 和 AML2 扩增的核小亚基核糖体 RNA 基因（SSU rDNA）的部分真菌 DNA 序列检查了 AMF 群落。获得的 AMF 序列分为 14 个系统发育型，系统发育型的数量（物种丰富度）也与土壤有效磷呈负相关（P <0.05）。这表明一些 AM 真菌可能适应高土壤有效磷条件。冗余分析表明，土壤 pH、土壤有效磷和 culta 梨叶片中 P 含量对 AMF 分布有显著影响。这些结果表明，土壤有效磷的积累影响了果园中日本梨根系中的 AMF 群落。
