15.5 Conclusions
The development of reliable molecular markers that are useful to breeding or
forensic applications needs to be based on knowledge of genes and of molecular
mechanisms underlying their action. Gene sequences have been accumulating inC.
sativaat a good pace, and have already led to the development of a number of
diagnostic markers for sex, chemotype, and for the study of the genetic structure of
this species.
However, while markers for the male sex and for the main chemotypes are
available and tested, several important traits are still lagging behind, both as basic
research and development of diagnostic tools. To give an example, an important
trait like monoecy still has a poorly investigated physiological, genetic and
molecular basis; similarly, traits that are increasingly important forfiber or medical
Cannabis,such as earliness, response to photoperiodic conditions, trichome density
andfiber quality are still poorly understood at the molecular level, and breeding
cannot yet take advantage of any effective tool for the rapid screening of the
germplasm.
Finally, even for a well-studied trait like chemotype, the huge variability present
in the germplasm for the variant cannabinoids keeps the way open to further new
investigations, as these are still needed for the biosynthesis of propyl- and
methyl-cannabinoids, that have emerged over recent years as important breeding
targets, due to their specific and potentially relevant therapeutic properties.
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