Amer. J. Bot. 64(6): 687-693. 1977
Jocelyn C. Turner, John K. Hemphill & Paul G. Mahlberg
Department of Plant Sciences, Indiana University, Bloomington 47401
Keywords: Cannabis sativa, Cannabaceae, Cannabinoid, gland, distribution, clones
The relationship between glandular trichomes and cannabinoid content in Cannabis saliva L. was investigated. Three strains of Cannabis, which are annuals, were selected for either a drug, a non-drug, or a fiber trait and then cloned to provide genetically uniform material for analyses over several years. The distribution of the number and type of glands was determined for several organs of different ages including the bract and its subtending monoleaflet leaf and the compound leaf on pistillate plants. Quantitation of glands on these structures was integrated with gas chromatographic analyses of organ cannabinoid profiles. A negative correlation was found between cannabinoid content and gland number for each of the three clones. Isolated heads of the capitate-stalked glands also were analyzed for cannabinoid content and found to vary in relation to clone and gland age. These studies indicate that cannabinoids may occur in plant cells other than glandular trichomes. The results of these studies emphasize the need for stringent sampling procedures in micromorphological studies on trichome distribution and analytical determinations of cannabinoid content in Cannabis.