Studies on Dual Mycorrhizas of Eucalyptus globulus and E.urophylla Ⅱ.Inoculant Efficacy on the Growth

The second part of the results based on a glasshouse experiment.The inoculant effectiveness of 4 VAmycorrhizal fungi and 1 ectomycorrhizal fungus alone or in combination on the growth of Eucalyptus globulus and E.urophylla saplings was reported.There were substantial differences on the growth among treatments (P 0.005).Large responses of height growth and biomass stimulated by fungal inoculation were observed for both plants during 16 week growing in a sterilized Karrakatta yellow sand.Average heights of inoculated E.globulus and E.urophylla seedlings were respectively increased by up to 28.86% (Lacc aria +Scutellospora, LS) and 86.65% (Laccaria+Glomus, LG),compared to those of uninoculated ones at 16 weeks after inoculation.Dry weights of sapling were up to 129.93% (tops) and 119.93% (roots) for E.globulus, 133.34% (tops) and 174.83% (roots) for E.urophylla respectively relative to controls.The growths of both plants weremore significantly enhanced by dual inoculation with Laccaria and one of 4 VAmycorrhizal fungi than those inoculated individually.There were strong interactions between fungal colonization and plant growth,which reflected the inoculation efficacy.Ectomycorrhizal fungi had amajor impact on root systemformsubstantially reducing the proportion of fine roots (specific root length),but this did not occur when only VAmfungi were present.The results also revealed that phosphorus level in soils greatly affected the growth of plants and interacted fungal efficacy as well.