Effects of Salinity and Mycorrhizal Inoculation (Glomus fasciculatum) on Growth Responses of Grape Rootstocks (Vitis spp.)

A pilot experiment was conducted to determine the effects of soil salinity and inoculation with arbuscular mycorrhizalfungus (Glomus fasciculatum) on growth (shoot length, leaf number, internode length, and total dry weight), sporecount and root colonisation of grape rootstocks (Salt Creek, St. George, Dogridge and 1613). Analysis of varianceresults revealed that increasing salinity reduces growth, spore count and root colonisation, with St. George rootstockshowing the highest reduction. Although all rootstocks responded positively to mycorrhizal inoculation, the extentof host preference varied significantly. Dogridge was the least preferred, while the 1613 rootstock was the mostpreferred. The arbuscular fungal symbiosis increased vegetative growth, with 1613 attaining the highest growthunder saline conditions. All the inoculated rootstocks exhibited longer internodes, indicating the beneficial roleof mycorrhizal inoculation for improving plant growth and salt tolerance. Based on overall growth and total drymatter accumulation, the salt tolerance ranking of the four rootstocks, in decreasing order, was Dogridge, SaltCreek, 1613 and St. George