Phenotype

Phenotype (Greek phainein "to show" + typos "form") is the set of observable traits of an organism — morphology, chemistry, growth habit, flowering time — arising from the interaction of genotype (G) with environment (E), commonly expressed P = G + E + G×E (Johannsen 1911; Acquaah 2012, Principles of Plant Genetics and Breeding). In cannabis breeding, "pheno-hunting" denotes selecting among seed-grown siblings of a given cross for individual plants ("phenotypes") expressing desired traits — resin yield, aroma, color, cannabinoid ratio — before cloning the winner for mass propagation. Vergara et al. (2021, PeerJ) demonstrated in a 297-individual hemp × drug backcross that widely assumed cannabis phenotypic correlations (leaf shape vs. cannabinoid content) lack a shared genetic basis, undermining phenotypic leaf-morphology diagnostics for Sativa/Indica assignment. Environmental plasticity makes cannabis phenotypes highly variable across grow conditions. → See also: Genotype, Chemotype, Cultivar.