The physical and chemical features of Cannabis plants grown in the United Kingdom of Great Britain and Northern Ireland from seeds of known origin--Part II: second generation studies.Bull Narc. 1983 Jan-Mar; 35(1):51-62.BN
A second generation of Cannabis plants has been grown from seeds produced by first generation plants which were raised in the United Kingdom of Great Britain and Northern Ireland from seeds taken from imported cannabis of known geographical origin and chemistry. The gross physical appearance of the second generation plants, in general, resembled their parents and the cannabis produced therefrom was not usually distinguishable from that derived from first generation plants. Although cannabinoid patterns were, in some cases, similar to those of both parents and original seedstock cannabis, there were many exceptions. The yields of cannabis were significantly higher than from first generation plants, but the tetrahydrocannabinol contents were lower. Although higher than in the original imported cannabis, the tetrahydrocannabinolic acid to tetrahydrocannabinol ratios in cannabis from second generation plants were lower than in cannabis produced from first generation plants.