Morphological and molecular study of sex determination in Cannabis sativa L.

Cannabis sativa L. is an important plant with various uses in pharmaceutical and paper production industries. Due to the higher priority of female and male Cannabis plants for pharmaceutical uses and fibre industry, respectively, reduction of the quality of products after pollination, and also for detection of better genotypes before pollination for breeding purposes, early determination of sex in Cannabis is one of the major concerns of researchers and farmers. Seeds of 26 accessions from different regions of Iran along with one accession from Afghanistan were planted in the field based on randomized complete block design with 10 replications. Five female and five male plants were sampled from each accession for molecular and morphological analyses. Thirteen ISSR primers and two SCAR markers were used. Also, morphological differences, which possibly related to sex were measured in the Cannabis populations under study. The results showed significant differences among the accessions within female and male plants for plant height, number of days to flowering, days after full bloom and height of the first flowering node. Male plants were generally, but not always, taller than female plants and had a shorter life cycle. The highest expected heterozygosity was found in the ISSR3 primer and the lowest in the UBC825 primer. In total, 143 polymorphic bands and one polymorphic band were amplified using ISSR and SCAR primers, respectively. Out of 143 polymorphic ISSR bands, only 10 markers had significant relations with the gender of this plant. MADC6 SCAR marker was monomorph across the accessions. On the other hand, MADC5 was a polymorphic marker and showed a significant relation with gender. These markers, especially MADC5, have the potential to be used in sex determination of C. sativa.