| Abstract: | Hevea brasiliensis is one of the important economic trees with a greateconomic value for natural rubber production. Symbiosis between roots of H. brasiliensis and arbuscular mycorrhizal fungi (AMF) is widely recognized, and canprovide a range of benefits for both of them. Hainan Island harbors is one of thelargest plantations of H. brasiliensis in China, whereas the information regardingthe diversity of AMF in the rhizosphere of H. brasiliensis on this island is scarce.The diversity of AMF species in the rhizosphere of rubber tree plantations in Hainanwas investigated in this study. A total of 72 soil samples from the rhizosphere of H.brasiliensis RY7-33-97 were collected. These included 48 samples from plantationsin 11 cities or counties that had been planted for 15–25 years, and 24 samples from ademonstrating plantation site of the China National Rubber Tree Germplasm Repository representing plantations with tree plantation ages from one to 40 year-old.Collectively, a total of 68 morphotypes of AMF, belonging to the genera of Archaeospora (1), Glomus (43), Acaulospora (18), Entrophospora (3), Scutellospora (2),and Gigaspora (1) were isolated and identified, as per morphological characteristicsof spores presented in the collected soil samples. Glomus (Frequency, F = 100%) andAcaulospora (F = 100%) were the predominant genera, and A. mellea (F = 63.9%)and A. scrobiculata (F = 63.9%) were the predominant species. AMF species differedsignificantly among collected sites in spore density (SD, 290.7–2,186.7 spores per100 g dry soil), species richness (SR, 4.3–12.3), and Shannon-Weiner index of diversity (H, 1.24–2.24). SD was negatively correlated with available phosphorus level inthe soil; SR was positively correlated with soil total phosphorus content; and H waspositively correlated with levels of soil organic matter and total phosphorus. Similarly, SD, SR, and H were also correlated with H. brasiliensis plantation age, andan increasing trend was observed up to 40 years. These results suggest that theAMF community was complex and ubiquitous in the island plantation ecosystemsof H. brasiliensis, with high species abundance and diversity. Soil factors and plantation age dramatically affected AMF diversity at species level. |
