Cannabis is suddenly big business. Declared illegal in many (most?) countries in the 1920s and 30s, there has been a huge resurgence in interest since its medicinal uses and relative recreational safety have been re-investigated. As a result of increased legality, a multi-billion industry has been born almost overnight in medical and recreational cannabis, and alongside this a restriction (both perceptual and actual) has been lifted from the industrial hemp sector.
From a plant breeding perspective, cannabis is interesting because there is no other developed world commercial crop so poorly characterised by science, both genetically and agronomically. For much of the last century cannabis has been bred by enthusiastic amateurs in an underground fashion. Creating and characterising germplasm collections has been difficult. Indeed, now that well funded research operations have got to work with a mass of popular varieties it has become clear – to quote Greg Baute of Aurora – there is “no evidence of consistent phenotypic, genetic or chemical differentiation between sativa and indica varieties”.
So, there is a lot of work to do, and a race to do it. Breeders are working to create homogeneity within their strains, understand how environment affects the chemotype of their varieties, and use more systematic and genetic level understanding to develop varieties with specific characteristics.
Supply and demand economics are also influencing breeding priorities. As supply grows and prices fall, the cost and efficiency of traditional indoor growing methods are coming under scrutiny. This is especially the case where the CBD will be extracted, a market which does not rely on the aesthetic appearance of the perfect “bud”, and where the extract itself is increasingly commoditised.
This has driven a move towards outdoor growing, a transition facilitated by the 2018 Farm Bill in the USA and by the attraction of a deep-rooted and potentially high margin addition to farmers’ rotations. Outdoor growing, along with concerns about pest management, is one of the reasons the sector is increasingly moving towards propagation from seed rather than from labour-intensive cuttings. Outdoor growing has also driven up the research agenda the importance of understanding the mechanisms that underpin how daylight affects flowering behaviour.
Despite the advances in genomic selection in breeding programmes, growing, crossing and selfing actual plants remains critical in these endeavours, which presents particular pollination control challenges.
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