Addressing microbial-induced pre- and post-harvest quality reduction in cannabis

随着大麻合法化（大麻，2018年10月，加拿大的大麻（大麻），用于医疗和娱乐市场的干大麻花（芽）和大麻衍生产品的生产和供应有所增加。大多数大麻生产（90%）发生在温室中，每个作物周期需要10周的时间来收获。收获后，将大麻花干燥至含水量为10-12%（重量）。持牌生产商（LP）面临的最大挑战是由于微生物和病原体入侵花卉造成的收获前后损失以及由于环境扰动造成的不可预测的花卉质量。此外，病毒病原体的日益流行正在造成尚未确定的质量损失。总酵母和霉菌（TYM）水平是大麻产品最终价值的一个关键因素-生产过程中高水平的微生物可能导致产品降级或拒收，每年可能导致数百万美元的损失。此外，由于环境压力、疾病或收获后损害造成的花发育不良会降低花的质量和毛状体中药用和精神化学品的水平。由于还没有开发出适当的方法来评估它们，因此很难对收获前后的花朵质量进行测量。拟议的研究将提供一些重大的科学和技术进步，这些进步可以作为提高加拿大大麻质量的创新工艺和技术加以实施，具体如下：㈠采用可预测的培养和分子方法来估计大麻生产设施中的TYM，以指导生产者最佳利用资源，尽量减少收获后的损失;（二）确定环境条件、大麻基因型和最大限度地减少TYM的收获后处理方法;（三）基于毛状体成熟分析的计算机辅助视觉方法，以评估最佳花朵质量;（四）更好地了解大麻中的病毒病复合体。这一为期三年的研究项目的一项重要成果是，加拿大各地的其他研究机构和大麻生产者可以利用一些新的研究方法，使加拿大人受益。

Following legalization of cannabis (Cannabis sativa L., marijuana) in Canada in October, 2018, production and supply of dried cannabis flowers (buds) and cannabis-derived products for medicinal and recreational markets have increased. Most cannabis production (90%) occurs in greenhouses, and each crop cycle requires a 10 week period to harvest. After harvest, cannabis flowers are dried to a moisture content of 10-12% (by weight). The greatest challenge facing licensed producers (LPs) is pre-and post-harvest losses due to microbial and pathogen invasion of flowers and unpredictable flower quality due to environmental perturbations. In addition, the increasing prevalence of viral pathogens is causing as-yet-undetermined losses in quality. The total yeast and mold (TYM) levels is a critical factor for final value of cannabis products - high levels of microbes during production can result in downgrading or rejection of product, potentially leading to millions of dollars in losses annually. In addition, poor flower development due to environmental stress, diseases or post-harvest damage can reduce flower quality and levels of medicinal and psychotropic chemicals in trichomes. Measurements of pre-and post-harvest flower quality are difficult to make as appropriate methods have not been developed to assess them. The proposed research will provide a number of significant scientific and technological advancements that can be implemented as innovative processes and technologies to improve cannabis quality in Canada, as follows: (i) a predictable culture and molecular based method to estimate TYM in cannabis production facilities to guide producers in optimal usage of resources to minimize post-harvest losses; (ii) identification of environmental conditions, cannabis genotypes and post-harvest handling methods that minimize TYM; (iii) a computer-assisted visual method based on trichome maturation analysis to assess optimal flower quality; (iv) a better understanding of the viral disease complex in cannabis. A number of novel research methodologies that can be utilized by other research institutions and cannabis producers across Canada to benefit Canadians will be an important outcome of this 3-year research project.