A single nucleotide polymorphism assay sheds light on the extent and distribution of genetic diversity, population structure and functional basis of key traits in cultivated north American cannabis

Morphometric approaches to Cannabis evolution and differentiation from archaeological sites: interpreting the archaeobotanical evidence from bronze age Haimenkou, Yunnan

Cannabis grains are frequently reported from archaeological sites in Asia, and hypothesized centers of origins are China and Central Asia. Chinese early cannabis remains are often interpreted as evidence of hemp fabric production, in line with early textual evidence describing ritualistic hemp cloth use and hemp cultivation as a grain crop. Modern measurements on cannabis varieties show distinct sizes between fibre or oil/fibre and psychoactive varieties, the former having larger seeds on average than the latter. This paper reviews the current macro-botanical evidence for cannabis across East, Central and South Asia and builds a comparative framework based on modern cannabis seed measurements to help identify cannabis use in the past, through the metric analysis of archaeologically preserved seeds. Over 800 grains of cannabis were retrieved from the 2008 excavation of Haimenkou, Yunnan, Southwest China, dating to between 1650 and 400 bc. These are compared with other known archaeological cannabis and interpreted through the metric framework. This offers a basis for exploration of the seed morphometrics potential to infer cannabis cultivation and diversification in uses. At Haimenkou, cannabis seeds size mostly plot in the range of overlapping psychoactive/fibre types; we therefore suggest that the cannabis assemblage from Haimenkou is indicative of a crop beginning to undergo evolution from its early domesticated form towards a diversified crop specialized for alternative uses, including larger oilseed/fibre adapted varieties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00334-023-00966-6.

Recent advances in Cannabis sativa genomics research

Cannabis (Cannabis sativa L.) is one of the oldest cultivated plants purported to have unique medicinal properties. However, scientific research of cannabis has been restricted by the Single Convention on Narcotic Drugs of 1961, an international treaty that prohibits the production and supply of narcotic drugs except under license. Legislation governing cannabis cultivation for research, medicinal and even recreational purposes has been relaxed recently in certain jurisdictions. As a result, there is now potential to accelerate cultivar development of this multi-use and potentially medically useful plant species by application of modern genomics technologies. Whilst genomics has been pivotal to our understanding of the basic biology and molecular mechanisms controlling key traits in several crop species, much work is needed for cannabis. In this review we provide a comprehensive summary of key cannabis genomics resources and their applications. We also discuss prospective applications of existing and emerging genomics technologies for accelerating the genetic improvement of cannabis.