相思菌根的菌种筛选及其接种效应研究

Mycorrhizal Fungal Screening and Inoculant Effectiveness for Two Acacia Species

VA菌根、外生菌根及菌根菌剂对马占相思和厚荚相思幼苗的接种结果表明 :VA菌根和外生菌根都可对两种相思幼苗形成侵染 ,菌根感染率达 4 9.5%～ 73.33% ;5个月后的马占相思苗木高比对照增加 53.9%～ 14 8.99% ,厚荚相思苗高增加 31.7%～ 95.39% ;马占相思生物量比对照增加 2 0 8%～ 396 % ,厚荚相思生物量增加 2 94 %～ 4 4 1.5% ;对 VA菌的菌根依赖性 (MD)测定结果表明 ,除厚荚相思对 B930 2菌株的依赖属中等外 ,两种相思对其它菌种的依赖性较强 (MD>30 0 )。在外生菌根方面 ,除厚荚相思对 992 15和 94 0 70两菌株依赖性属中等外 ,对其它菌种的依赖性均较强 ,特别是马占相思对 94 39菌株 ,其 MD值达 542 ;对 6种菌剂而言 ,以美 2菌剂效果最好 ,MD值均大大高于其它菌株。试验结果还表明 ,就两个类型菌根比较而言 ,VA菌根对苗木的促生效果优于外生菌根的效果 ;就几种菌株比较来看 ,B930 1和 B930 2两个 VA菌和 94 39、992 15及 94 0 70三个外生菌对马占相思效果好 ,而 VA菌 990 0 4、930 1和外生菌根菌 99132、94 39菌株对厚荚相思效果好 ;

Preliminary results showed that the seedlings of Acacia mangium and A. crassicarpa were capable of forming ectomycorrhizal (ECM) and vesicular arbuscular mycorrhizal (VAM) associations. The average infective rates of both mycorrhizal associations varied from 49.5 % to 73.33%. Five months after inoculation,the average heights of A.mangium and A.crassicarpa were increased by 53.9%～148.99% and 31.7%～95.39% respectively compared to those of controls. The biomass was accordingly increased by 208%～396% and 294%～441.5% respectively.Seedilings of both tree species indicated strong mycorrhizal dependency (MD) on inoculant fungi,except relatively weak MD for A.mangium on either VAM fungus isolate B9302 or ECM fungus 99215 and 94070.The highest MD were 542 of A. crassicarpa on ECM isolate 9439. Another experiment with various inoculum products showed that American inoculum No.2 posed the best effectiveness on the growth of seedlings. Among these fungal isolates,more compatible isolates for the two Acacia species were screened and can be further tested in field trials. Experimental results also indicated tha[WT5,5”BZ]t inoculation with mycorrhizal fungi could enhance nodule formation by rhizobia.