Inheritance of photoperiod sensitivity and cannabinoid stability in F2 generation of hemp variety ‘CBD Charlotte’s Angel’: Implications for biological intellectual property protection

Abstract

Importance of the work: A breeding-based biological barrier in the F2 generation can effectively complement the legal protection of the proprietary F1 hemp variety. Objectives: To evaluate photoperiod sensitivity and cannabinoid stability inheritance in a ‘CBD Charlotte’s Angel’ F2 population to validate biological intellectual property (IP) protection. Materials and Methods: Female cuttings of CBD Charlotte’s Angel were induced to develop hermaphroditic flowers using a 30 parts per million colloidal silver solution. These plants were self-pollinated to produce F2 seeds. In total, 162 F2 plants were cultivated and evaluated in a plant factory with an artificial lighting environment. Results: Photoperiod sensitivity in the F2 population followed a 3:1 segregation ratio (photoperiod-sensitive to photoperiod-insensitive; chi squared = 0.67, p = 0.414), confirming that the photoperiod sensitivity in this variety was controlled by a single dominant gene. Conversely, the cannabinoid profiles remained within the expected Type III range across all sampled individuals; all F2 plants consistently maintained high cannabidiol (CBD) levels (mean ± SD = 10.68 ± 2.08%) and low tetrahydrocannabinol levels (0.024±0.065%), with no significant deviation from the parental variety. Based on these results, while the parental lines exhibited physiological divergence, they had high genetic stability in cannabinoid biosynthesis, suggesting putative homozygosity at the CBD-synthase gene. Main finding: Segregation of photoperiod sensitivity in the F2 generation complicated reverse hybridization and challenged parental line recovery. Along with consistent cannabinoid profiles, this forms a strong breeding-based biological barrier that safeguards proprietary hemp hybrids.