Physiological response of rosemary plants to some vitamins

ABSTRACT

The effect of foliar application of nicotineamide, ascorbic acid and thiamine [25, 50 and 75 mg/l] on vegetative growth and chemical constituents of rosemary plants was studied. Most criteria of vegetative growth were significantly affected by application of the vitamins. Foliar application of nicotineamide to rosemary plants significantly promoted plant height, number of branches and fresh and dry weights of herb. Increasing nicotineamide concentration to 75 mg/l caused increase in the growth of the two cuttings. Ascorbic acid treatments significantly increased plant height, number of branches, fresh and dry weights of herb in both cuttings as well as chemical constituents. The highest recorded results were obtained in plants treated with 75 mg/l ascorbic acid. Foliar application of thiamine to rosemary plants significantly promoted plant growth and chemical constituents of the herb. Increasing thiamine concentration to 50 mg/l caused increase in plant growth, while increasing it to 75 mg/l led to a decrease in the growth parameters in the two cuttings. The GC-MS analysis of essential oil extracted from Rosmarinus officinalis L. plants treated with these vitamins revealed that 1,8 cineole, camphor and bornyl acetate are the major constituents [more than 9%] in all treatments, while alpha-pinene and linalool are also dominant in all treatments, respectively, except the essential oil of plants treated with 25 mg/l [NA] that recorded 4.95% alpha-pinene. Plants treated with 25 mg/l [AA] showed that alpha-bisabolol and alpha- humulene recorded the most dramatic changes and reached their maximum values of 11.31% and 4.85%, respectively, which may be at the expense of 1,8-cineole and linalool which decreased dramatically and showed the least value compared with the other treatments