Time course of cannabinoid accumulation and chemotype development during the growth of Cannabis sativa L

Abstract

The time course of cannabinoid accumulation in the leaves of individual plants of three Cannabis accessions was determined by gaschromatographic analysis in greenhouse-grown plants. The total amounts and the concentration ratios of CBD, THC and CBG were determined; two accessions (an experimental hybrid, (21R £ 15R) £ NL, and plants from a seized seed lot) were found chemotypically uniform, with all plants belonging to chemotpe II (mixed) and I (high THC) respectively. The Carmagnola accession showed chemotypic heterogeneity, with a majority of plants belonging to chemotype III. The CBD/THC and CBG/CBD ratios were shown to be largely constant in the leaves, since 28 and until 103 days after sowing, and consistent with the ratios determined on mature inXorescences. CBD and THC maximum amounts in the leaves showed a peak in the leaves around 80 days from sowing, and were shown to be simultaneous during the growth period, irrespective of the chemotypes. Callus cultures were obtained from all the Wve diVerent chemotypes (I, II, III, IV, V), and GC analyses were performed. Independently of the type and amount of cannabinoids in the mother plants, it was conWrmed that callus cultures of Cannabis were not able to produce detectable amounts of any cannabinoids.

Characterisation of cannabinoid composition in a diverse Cannabis sativa L. germplasm collection

“…Chemotypes have previously been classified on the basis of CBD total : THC total log 10 histogram frequency distributions (Hillig and Mahlberg 2004;Pacifico et al 2008;Staginnus et al 2014;Tipparat et al 2012), with CBD total : THC total log 10 ratio of 0.0 (Pacifico et al 2008) and -1.0 being used as an arbitrary division between chemotype I and II (Hillig and Mahlberg 2004;Tipparat et al 2012). In the present study chemotype II B THCAS B CBDAS genotypes were found to exceed these log 10 ratios, albeit the latter log 10 ratio of -1.0 was only exceeded by a single individual I-3 (-1.15).…”

“…4). Selecting for chemotype III B CBDAS genotypes may prove especially beneficial for development of uniform plant lines for hemp fibre, seed, and pharmacological production, given the strong association between chemotype III and THC content \0.2 % DW (Pacifico et al 2008;, and growing interest in CBD(V)A and CBD(V) derivatives as pharmacological entities (De Petrocellis et al 2011;Gallily et al 2015;Hill et al 2013;Iseger and Bossong 2015). However, additional cannabinoid profiling is required in order to differentiate cannabinoid homologue compositions and to characterise CBD total :-THC total chemotype II variability accurately.…”

“…Residues of THCA in chemotype III are thought to be due to an imperfect capacity of CBDA synthase to form CBDA (De Meijer et al 2003). Chemotype III individuals have been observed to deviate transitionally from III to II during early stages of plant development (Pacifico et al 2008). THCA residue formation may have occurred in H-3 during this period and the remaining CBGVA substrate catalysed to CBDVA during later developmental stages.…”

Cultivation and Breeding of Cannabis sativa L. for Preparation of Standardized Extracts for Medicinal Purposes

“…From sequential harvesting studies on C. sativa chemotype it is evident that the concentration of cannabinoids in the flowers increases as the plant develops in the full flowering phase (Barnicomparini et al 1984;Vogelmann et al 1988;Pacifico et al 2008;Muntendam et al 2012). In basic experiments from the past it is obvious that the overall cannabinoid levels are significantly influenced by other factors: the plant's sex (Fetterma et al 1971;Fairbairn and Rowan 1975), the strain type , phytogeographic area (Hillig and Mahlberg 2004a, b), light intensity (Mahlberg and Hemphill 1983), UV-B radiation (Zhang and Bjorn 2009), dry and windy conditions can raise cannabinoids content, and indoor cultivation conditions and infrastructure (Vanhove et al 2011).…”

“…On the assumption that production of Δ 9 -THC is the main objective then harvesting is done when the crop is in full bloom (Vogelmann et al 1988;Pacifico et al 2008;De Backer et al 2012). There minor published information on the methods of harvesting C. sativa.…”