The team tested three such fungi on cuttings of the MM106 rootstock, with and without two growth regulators - the rooting hormone IBA and the rooting inhibitor cinnamic acid.
It found that inoculated rootstock cuttings showed "a significantly higher percentage" of rooting, ranging from 27-58 per cent, compared to untreated controls, as well as greater growth. Rooting was highest for fungi used with IBA, but the cinnamic acid also improved growth in inoculated specimens.
Longer roots and more leaves were also recorded on plants treated with the fungi, whether or not they had been treated with IBA, and the plants also had higher levels of chlorophyll and of other compounds capable of alleviating plant stress.
Writing in the Journal of Horticultural Science & Biotechnology, the researchers said: "To obtain benefits in horticultural production systems, the inoculum should be present...in cutting propagation."
Apple growing is widespread in India and demand is rising.