Influence of IAA, 28-homobrassinolide and 24-epibrassinolide on adventitious rooting in grapevine.

In this research, influence of auxin and brassinosteroids on rooting of American grapevine rootstocks (140 Ru and 41 B) was investigated. Hormones and their concentrations used were indole butyric acid (IBA); 0 (control), 1000, 1500, 2000 and 4000 ppm for 5-second dipping, and 22(S),23(S)-homobrassinolide (HBR) and 24epibrassinolide (EBR); 0 (control), 10, 0,25, 0,50 and 1,00 ppm for 10-minute dipping. In the cuttings allowed to grow and develop in a growth chamber, firstly the ratios of sprouting, rooting and healthy plant were calculated. Later, in the rooted and sprouted cuttings only, root development (root number, longest root length, root development scale, fresh and dry root weights, dry root ratio) and shoot development (primary shoot length, node number, shoot number, auxiliary shoot number) were determined. Applications of 5 second 1500 ppm IBA and 10 minute 1.00 ppm HBR were shown to stimulate rooting and healthy plant ratios in the rootstock 41 B. EBR, on the other hand, did not yield any success. Along with 1000 ppm IBA, 0.50 and 1.00 ppm HBR, all EBR treatments resulted in noticeable increase in the ratios of rooting and healthy plant in 140 Ru. Although 140 Ru had always better growth and development compared to 41 B, IBA applications did not have distinctly significant effects on root and shoot development of the two rootstocks. According to results of this study, it can be stated that brassinosteroids might be useful to induce rooting in grapevine rootstocks cuttings.