Response of grapevine rootstocks to inoculation by arbuscular mycorrhizal fungi

Abstract

Grapevine is highly dependent on arbuscular mycorrhizae fungi (AMF). Grapevine rootstocks have
different rooting abilities, and some of them show difficulties to root. The present study intended to evaluate the effects of inoculation of different AMF on rooting and vegetative growth of grapevine rootstocks with different rooting abilities. The experiment was carried out at Eldorado do Sul, RS, with two Vitis sp. used as rootstock
cultivars (101-14 and 420-A) and three AMF species (Acaulospora scrobiculata, Glomus clarum and Scutellospora heterogama). Rootstock cuttings were placed in greenhouse conditions, in pots with a soil substrate:sand: decomposed bark residue of Acacia mearnsii (2:2:1), which had been previously desinfested (phormaldehyde at 10%),
amended or not with AMF inoculum. Rootstock ‘101-14’ presented the highest rooting ability (95%, compared to 80% of the ‘420-A’) the highest number of roots/plant (41, compared to 12 of the ‘420-A’), and the highest reserve contents (33,36% in the cuttings and 28,06% in the roots, compared to, respectively, 30,53% and 25,3% on ‘420-A’).
Acaulospora scrobiculata and G. clarum did not affect rooting ability, vegetative growth and the reserve contents of both cultivars while inoculation with S. heterogama resulted in leaf area reduction on ‘420-A’, though not influencing the other evaluated parameters.