Abstract

N. K. Srivastava*and R. K. Lal

Intraspecific variations in four widely cultivated cultivars of vetiver (Vetiveria zizanioides L) were analyzed for physiological basis of regulation of essential oil accumulation. The cultivars had the same biosynthetic route of oil accumulation but differed with respect to yield parameters. Among the four cultivars, Gulabi showed highest yield of oil while Kesari incorporated maximum 14C into essential oil indicating efficient biosynthetic use of leaf assimilated metabolites transported to roots. Among the metabolite fraction in root, Gulabi had maximum 14C content in ethanol soluble and ethanol insoluble fraction whereas in leaf sugar, amino acid and organic acid had higher content. The leaf photosynthetic rate showed significant positive association with root biomass. The 14C label in metabolite sugar showed significant positive association with oil content in root, root biomass and oil yield. Efficient cultivar translocated a higher portion of leaf carbon assimilate towards the root and also towards the biosynthesis of essential oil. Thus, the physiological capacity of cultivars in terms of shoots photosynthetic capacity, assimilation of 14CO2 and partitioning of metabolites between shoot and root regulate accumulation of essential oil.