Effect of brassinostreoidin on rooting of some grapvine rootstocks

Brassinosteroids have found themselves a place among the hormones that regulate plants? growth and development in recent years. These group of hormones affect development from seed germination to senescence. Studies that show that brassinosteroids increase seed germination of annual plants have led us to ponder on possible effects of these hormones to increase adventitious rooting of perennial plants. This research project prepared under the light of this thought was aimed to study the effects of brassinosteroids on rooting of some American grapevine rootstocks (1103P, 110R, and 99R) used frequently in producing grafted plants. For this purpose, rootstock cuttings were dipped in to five different concentrations (0.00, 0.05, 0.10, 0.15 and 0.25 ppm) of 22(S)-23(S)-homobrassinolide and planted into peat-perlite (2:1) mixture. After development was attained, some rooting characteristics (fresh-dry root weight, root number, and development level) were assessed. Some shoot growth features were also determined. At the end of the trials carried out for two seasons, the characteristics studied were observed to be under the influence of the rootstock genotype rather than the application concentrations of the chemical. Generally, the best root and shoot growth was obtained in 1103P followed by 110R. Root development was influenced by both the rootstock and the concentrations of the substance. The lowest concentration induced more roots in 1103P, while it was the 0.15 ppm that resulted in the highest root number in 99R. No significant differences were observed in 110R.Key words: grape, rootstock, brassinosteroid, rooting