Cannabinoids are important chemotaxonomic markers unique to Cannabis. Previous studies show that a plant's dry-weight ratio of Δ(9)-tetrahydrocannabinol (THC) to cannabidiol (CBD) can be assigned to one of three chemotypes and that alleles B(D) and B(T) encode alloenzymes that catalyze the conversion of cannabigerol to CBD and THC, respectively. In the present study, the frequencies of B(D) and B(T) in sample populations of 157 Cannabis accessions were determined from CBD and THC banding patterns, visualized by starch gel electrophoresis. Gas chromatography was used to quantify cannabinoid levels in 96 of the same accessions. The data were interpreted with respect to previous analyses of genetic and morphological variation in the same germplasm collection. Two biotypes (infraspecific taxa of unassigned rank) of C. sativa and four biotypes of C. indica were recognized. Mean THC levels and the frequency of B(T) were significantly higher in C. indica than C. sativa. The proportion of high THC/CBD chemotype plants in most accessions assigned to C. sativa was <25% and in most accessions assigned to C. indica was >25%. Plants with relatively high levels of tetrahydrocannabivarin (THCV) and/or cannabidivarin (CBDV) were common only in C. indica. This study supports a two-species concept of Cannabis.

The unbranched nonarticulated laticifer, including its latex, and capitate glandular trichomes from Cannabis sativa L. were analyzed in fresh and cryostat preparations with histochemical procedures for the presence of cannabinoids, alkaloids, and other selected cellular components. A positive response to cannabinoid indicators, Duquenois-Negm, fast blue salt B, Gibb, and Beam reagents occurred in laticifers, as well as exuded latex and in disc cells of epidermal capitate glandular trichomes. No response or only an apparent background response to these reagents was detected in other cells. Alkaloids were detected histochemically in laticifers and exuded latex with Wagner, Dittmar, Ellram, chromic acid, Hager, and Dragendorff

No abstract

No abstract

Chromic acid, iodine‐potassium iodide and Dragendorff reagent were employed to identify reactive cells that may indicate sites of alkaloid accumulation in fresh tissues and latex of C. roseus. Laticifers in all parts of the mature plant and certain parenchyma cells in the cortex and pith regions accumulated reaction products of these alkaloid indicators. These same cells showed primary fluorescence, accumulated vital dyes and lipid indicators in excess of other cells, and exhibited a more intense nadi reaction than other cells. Tests on fresh tissues are interpreted to indicate possible qualitative and quantitative differences in alkaloid content between subterranean and aerial portions of the plant and between mature and immature tissues. These studies showed that reactive products are unevenly distributed in cells and organs of the plant and can be microscopically detected only in laticifers and specialized parenchyma cells.