Discovering the epigenetic mechanisms and factors that influence sex change in dioecious cannabis.

大麻（大麻sativa L.）具有悠久的人类使用历史，用于各种应用，包括纤维，食品，药物及其精神活性特性。大麻是一种一年生雌雄异株植物，具有独立的雄性（XY）和雌性（XX）植株。在大麻中，两性二形现象发生在植物发育的后期（即开花），伴随着形态二形现象。一般来说，雌花的花序紧凑，很少松散，花在主枝和短侧枝上，而雄花的花序为松散的顶生和腋生圆锥花序。大麻被认为是雌雄异株植物中性别决定和性别遗传机制最复杂的植物之一。虽然大麻性别的基因决定论被认为是遗传改良的重要遗传特征，但其性别并不为人所知，是可塑的，可以改变。除环境因素外，外源植物生长调节剂或抑制剂的应用可以改变或逆转大麻的性别形态。鉴于此，我假设性别不是由特定的染色体决定的，而是由整个基因组决定的，由基因和染色体的相互作用决定的。因此，所有的个体都能够表达一种或另一种性别。因此，这里出现的根本问题是“基因和表观遗传因素如何相互作用并调节大麻中的性表达？”因此，在这里，我建议找到这个基本问题的答案，这对理解大麻中的性别生物学及其在遗传改良方面的应用具有重大意义。这一建议也将为其他具有重要商业价值的雌雄异株作物（如芦笋、木瓜和啤酒花）提供启示。

Cannabis (Cannabis sativa L.) has a long history of human use for a variety of applications including fibre, food, medicine, and for its psychoactive properties. Cannabis is an annual dioecious species with separate male (XY) and female (XX) plants. In cannabis, sexual dimorphism occurs in a late stage of plant development (i.e., flowering) accompanied by a morphological dimorphism. In general, females produce compact and rarely lax inflorescence with flowers on the main shoot and short lateral branches, while males produce an inflorescence in the form of loose terminal and axillary panicles. It is considered that cannabis has one of the most complicated mechanisms of sex determination and sex inheritance among dioecious plants. While the genetic determinism of sex in cannabis is considered an important heritable trait for genetic improvement, its sexuality is not well known, is plastic and can be changed. In addition to environmental factors, application of exogenous plant growth regulators or inhibitors can modify or reverse sex morphology in cannabis. In view of this, I hypothesize that sex is not determined by particular chromosomes, but by the whole genome, and by the gene and chromosome interactions. Thus, all individuals are able to express one or the other sex. As a result, the fundamental question arising here is "how genetic and epigenetic factors interact and regulate sex expression in cannabis?" Therefore, here I propose to find answers to this fundamental question which has major implications for understanding the biology of sex in cannabis and its application for genetic improvement. Insights from this proposal will also shed light on other commercially important dioecious crops such as asparagus, papaya, and hops.