Potential of marker-assisted selection in hemp genetic improvement

The development and applications of molecular markers to hemp breeding are recent, dating back only to the mid-1990s. The main achievements in this field are reviewed. The analysis of Cannabis germplasm by RAPD, AFLP and microsatellites is discussed, with its consequence for the still debated species concept in Cannabis. DNA-based markers have also been exploited in the field of forensic science, in an attempt to discriminate licit from illicit crop. The main applications of the molecular markers to the breeding, however, have been achieved with the development of markers closely linked to the male sex and to some of the most relevant chemotypes. Active research is carried out by several groups in the field of identification and characterization of the genes involved in fiber quality and quantity, and in the determination of monoecy, another very important target of hemp breeding. Besides, markers associated to new, potentially useful chemotypes are being developed, for the marker-assisted breeding of pharmaceutical Cannabis.