Disease Resistance Monogenic

Disease resistance monogenic refers to plant immunity controlled by a single gene locus, conferring resistance to a specific pathogen or disease. In cannabis breeding, monogenic resistance traits are often selected for rapid introgression into cultivars vulnerable to powdery mildew, root pathogens, or viral infections. Breeders working in this category identify source germplasm carrying dominant or recessive resistance alleles, then backcross them into elite genetic backgrounds. Monogenic systems are predictable in inheritance patterns, making them valuable for stabilizing resistance in F2 and F3 generations. Unlike polygenic resistance (controlled by multiple genes), monogenic traits follow clear Mendelian segregation, simplifying phenotypic selection. This classification is foundational in modern cannabis breeding programs targeting disease-prone environments or cultivar preservation.

Breeders use monogenic resistance markers to rapidly pyramid single-gene defenses into commercial cultivars without extensive field screening. Predictable 3:1 or 1:1 segregation ratios in test crosses allow rapid identification of resistant offspring and elimination of susceptible genotypes in early generations.