Glomus macrocarpum:: a potential bioinoculant to improve essential oil quality and concentration in Dill (Anethum graveolens L.) and Carum (Trachyspermum ammi (Linn.) Sprague)

The effects of application of two arbuscular mycorrhizal (AM) fungi Glomus macrocarpum and G. fasciculatum on shoot biomass and concentration of essential oil in Anethum graveolens L. and Trachyspermum ammi (Linn.) Sprague fruits were evaluated. Results revealed significant variation in effectiveness of the two AM fungal species. AM fungal inoculation in general improved the growth of the plants. On mycorrhization, the concentration of essential oil increased up to 90% in dill and 72% in carum over their respective controls. Glomus macrocarpum was more effective than G. fasciculatum in enhancing the oil concentration. The constituents of the essential oils were characterized by gas liquid chromatography. The levels of limonene and carvone were enhanced in essential oil obtained from G. macrocarpum-inoculated dill plants, while G. fasciculatum inoculation resulted in a higher level of thymol in carum.