Review of Flowering Control in Industrial Hemp

摘要

Hemp (Cannabis sativa L.) is a dioecious annual that commences its reproductive cycle when photoperiods are shorter than a crit ical length. Photoperiod-sensitive varieties grown in low latitudes with short-day lengths tend to produce early /lowering, short plants affecting the yield and quality of the fiber. The photoperiodic sen sitivity of the crop could be controlled by the activation or deacti vation of genes triggered by the change in light duration perceived by photoreceptive pigments. The sexual dimorphism of Cannabis is genetically determined by the XY chromosomal mechanism although sexual morphology is primarily a result of endogenous plant growth regulator levels that fluctuate in response to envi ronmental variables. Occurrence of occasional hermaphroditic flowers and monoecious plants are probably the result of these fluc tuations. Understanding the mechanisms of photoperiodicity and sexual inheritance contributes to advances in breeding and crop management that may underpin the expansion of the commercial cultivation of the crop in nontraditional agroecological domains.