6种外生菌根真菌对西南桦幼苗的接种效应

Effect of six ectomycorrhizal fungi inoculation on Betula alnoides clonal seedlings

摘要:

【背景】西南桦是兼具内生、外生菌根的典型菌根营养型树种，菌根化育苗是其壮苗培育的有效措施。【目的】揭示外生菌根真菌对西南桦无性系幼苗生长和养分含量的影响，为其菌根化育苗筛选优良外生菌根真菌提供科学依据。【方法】以BY1、FB4、FB4+和A5等4个西南桦优良无性系为研究对象，选用土生空团菌(Cenococcum geophilum)、松乳菇(Lactarius deliciosus)、黄硬皮马勃(Scleroderma flavidum)、多根硬皮马勃(S. polyrhizum)、褐环乳牛肝菌(Suillus luteus)和红绒盖牛肝菌(Xerocomus chrysenteron) 6个外生菌根真菌进行盆栽接种试验，分析接种处理间及无性系间苗高、地径、生物量以及养分含量差异。【结果】6个菌种均能与西南桦无性系幼苗形成外生菌根共生体，接种多根硬皮马勃与黄硬皮马勃显著促进了幼苗生长和养分吸收(P<0.05)，说明其与幼苗的亲和力明显优于其它菌种。尽管菌根侵染率在4个无性系之间无显著差异(P≥0.05)，但各菌种对FB4、BY1幼苗生长的促进作用显著强于其它2个无性系。【结论】多根硬皮马勃和黄硬皮马勃可作为西南桦菌根化育苗的优选菌种。

Abstract:

[Background] Betula alnoides is a typical mycorrhizal nutritional tree species with both arbuscular mycorrhizae and ectomycorrhizae, and mycorrhizal inoculation is an effective measure to grow its robust seedlings. [Objective] The objectives of this study are to reveal the effects of ectomycorrhizal fungi (ECMF) inoculation on seedling growth performance and nutrient contents of B. alnoides clones, and to screen suitable ectomycorrhizal fungi species as well as to provide scientific evidence for growing mycorrhizal seedlings of these species. [Methods] Seedling height, root collar diameter, biomass and nutrient contents of four B. alnoides clones, BY1, FB4, FB4+ and A5, were studied under inoculations of six ECMF including Cenococcum geophilum, Lactarius deliciosus, Scleroderma flavidum, Scleroderma polyrhizum, Suillus luteus and Xerocomus chrysenteron through a pot cultivation trial, and their differences were analyzed among different ECMF and clones. [Results] Seedling roots of four B. alnoides clones could be colonized by all six ECMF, in particular, S. polyrhizum and S. flavidum could remarkably promote growth and nutrient absorption of B. alnoides seedling after inoculation (P<0.05), inferring that these two ECMF demonstrated stronger affinity for clonal seedlings than other ECMF. There were not significant differences in mycorrhizal colonization rate among four clones, whereas the positive effects of ECMF on seedling growth of FB4 and BY1 were remarkably better than those of the other two clones. [Conclusion] It is recommended that S. polyrhizum and S. flavidum be applied in growing mycorrhizal seedling of B. alnoides.