(Fig.19.11). The results also show there is a considerable level of genetic diversity
among strains of marihuana developed for commercial production, as well as within
strains (Fig.19.12).
The ISSR results identify a potential problem likely to be encountered within the
marihuana production industry—that inadvertent mixing of strains, or misidentifi-
cation or mislabeling of strains, can occur, especially among those that may be
phenotypically similar and closely related genetically. While the ISSR primers do
not identify the regions of the DNA where these changes are occurring, since they
target random inter-sequence repeat regions, more targeted methods such as
genotype-by-sequencing approaches (described below) will shed more light on the
nature of these genetic differences. The ISSR primers also can confirm the genetic
similarity among presumably related strains.
19.9 Amplified Fragment Length
Polymorphism (AFLP) Analysis
DNAfingerprinting using AFLP markers was previously used to characterize 18C.
sativasamples from 5 different locations representing 3 geographical regions in
Turkey (Hakki et al. 2003 ). In addition, AFLP could be used to distinguish mari-
juana cultivars from hemp (Datwyler and Weiblen 2006 ) as well as determine the
extent of genetic diversity in hemp populations in China (Hu et al. 2012 ) and also
to detect sex-specific markers in hemp (Flachowsky et al. 2001 ).
Fig. 19.11Dendrogram showing the genetic relationship among 8 strains of cannabis used in
commercial production and originating from diverse sources. ISSR primers shown in Table19.1
were used in the analysis
410 Z.K. Punja et al.