Genetic and epigenetic stability in Cannabis sativa mother plants

大麻母株的遗传和表观遗传稳定性

• 批准号: 555969-2020
• 负责人: Jones, Andrew
• 金额: $ 3.86万
• 依托单位: University of Guelph
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=722773
• 关键词: Genetic; epigenetic; stability; Cannabis; sativa

Medicinal and recreational Cannabis has become a mult-billion dollar industry in Canada and is rapidly expanding around the world. Due to the variability among seedlings and Health Canada's stringent requirements, Cannabis is propagated using clonal means to produce uniform plants and products. This requires mother plants to be maintained indefinitely as a source of propagation material. A commonly observed phenomenon is that cuttings taken from a mother plan change over time, generally becoming less vigorous with lower levels of cannabinoids. These changes lead to lower productivity and batch to batch variability. The objective of this proposal is to investigate two potential mechanisms for this and develop best practices to prevent or remediate the decline. The first potential mechanism that will be investigated is genetic drift due to the accumulation of somatic mutations. To investigate this, samples from various parts of the plant will be sequenced to quantify the mutation rate. If mutations are found to accumulate, plants will be propagated from different regions of the plant (bottom vs top) over multiple cycles to compare genetic fidelity. This experiment will help to determine the rate of genetic drift in Cannabis and establish best practices to minimize it. The second potential mechanism that will be investigated is epigenetic changes due to loss of juvinility. To test this, cuttings will be taken from the bottom (more juvinile) and top (more mature) portion of the plant over several cycles. These cuttings will be evaluated for morphological juvinility traits. Transcriptome and DNA methylation will be evaluated to determine the cause of any differences. Additionally, plants produced through tissue culture, which is generally known to re-juvinate plants, will be compared to stem cuttings in the same manner. This part of the project will determine if epigenetic changes are contributing to the observed changes and develop approaches to minimize the decline. Overall, this project will help to identify the mechanism underlying and establish approaches to prevent or reverse the decline in plant quality that has been observed.

医疗和娱乐用大麻在加拿大已经成为一个价值数十亿美元的产业，并在世界各地迅速扩张。由于苗木的多样性和加拿大卫生部的严格要求，大麻的繁殖使用克隆方法来生产统一的植物和产品。这就要求母植物作为繁殖材料的来源被无限期地保存。通常观察到的现象是，取自母亲的插穗会随着时间的推移而变化，通常会随着大麻素水平的降低而变得不那么旺盛。这些变化导致生产率降低和批次之间的可变性。这项提案的目的是调查这方面的两种可能机制，并制定最佳做法，以防止或补救这种下降。将被研究的第一个潜在机制是由于体细胞突变的积累而导致的遗传漂移。为了调查这一点，将对来自植物不同部分的样本进行测序，以量化突变率。如果发现突变累积，植物将在多个周期内从植物的不同区域(底部和顶部)繁殖，以比较遗传保真度。这项实验将有助于确定大麻的遗传漂移率，并建立将其降至最低的最佳做法。第二个将被研究的潜在机制是由于幼稚丧失而引起的表观遗传变化。为了测试这一点，将在几个周期内从植株的底部(更幼稚的)和顶部(更成熟的)采集插条。将对这些插穗进行形态幼嫩特性的评估。将对转录组和DNA甲基化进行评估，以确定任何差异的原因。此外，通过组织培养产生的植株将以同样的方式与茎插条进行比较。该项目的这一部分将确定表观遗传变化是否有助于观察到的变化，并制定将下降降至最低的方法。总体而言，该项目将有助于确定潜在的机制，并建立防止或扭转已观察到的植物质量下降的方法。