Effect of some cultivars of native grapevine as rootstocks and triachenetanol on the ‎physiology of ‘Bidaneh Sefid’ grapevine scion (Vitis vinifera L.), under drought ‎stress

Use of drought tolerant grapevine rootstocks and application of garden management practices, such as the use of plant growth regulators, can be effective in achieving drought control methods. For this purpose, a factorial experiment based on a completely randomized design was conducted with three replications in greenhouse conditions in 2018 in order to study the effect of triacontanol on the physiological characteristics of grafted plantlet of grapevine on two native rootstocks of Iran under drought conditions. The treatments consisted of two rootstocks (Khoshnav, Sorkhak Ghouchan) and Bidaneh sefid (no grafting), three levels of drought stress including soil water potential of -0.2 (control), -0.7 and -1.5 MPa, and three concentrations of triacontanol (0, 50 and 100 μM). The measured traits included ratio dry weight to leaf area (LMA), membrane cell stability (MSI), total chlorophyll, proline, glycinebetaine, relative water content (RWC), catalase (CAT) and peroxidase (POX) activity. Based on the results, drought stress reduced LMA (25%), MSI (5%), chlorophyll (20%) and RWC (5%) and triacontanol treatments increased LMA (20%), MSI (4.5%), chlorophyll (14%), RWC (2.5%), glycinebetaine (27%), proline (22%), and antioxidant activity of catalase (23%) and peroxidase (8%). plantlet with Khoshnav rootstock showed better results than the control plantlet, and triacontanol improves drought tolerance in plantlets.