Ornamental Plant Breeding and Varieties: A Comprehensive Review

Ornamental plant breeding represents one of the most dynamic and economically significant sectors within horticulture. Globally, the ornamental plant industry generates revenues exceeding USD 100 billion annually, with continuous demand for novel cultivars exhibiting superior aesthetic traits, extended vase life, disease resistance, and environmental adaptability. This comprehensive review synthesizes contemporary knowledge on ornamental plant breeding methodologies, genetic resources, and the commercialization of new varieties across major ornamental crops including roses (Rosa spp.), chrysanthemums (Chrysanthemum morifolium), tulips (Tulipa spp.), orchids (Orchidaceae), and other floriculture species. The review addresses classical breeding approaches—hybridization, selection, and mutation breeding—alongside modern biotechnological tools including molecular marker-assisted selection (MAS), genomic selection, somatic hybridization, and CRISPR/Cas9-mediated genome editing. Special attention is given to the genetic basis of ornamental traits such as flower color, fragrance, plant architecture, and stress tolerance. The role of polyploidy, interspecific hybridization, and epigenetic regulation in generating phenotypic novelty is critically discussed. Furthermore, this paper examines intellectual property frameworks including plant patents and plant breeders' rights (PBR) that govern the commercialization of new ornamental varieties. Emerging trends such as climate-smart breeding, consumer-driven trait preferences, and digital phenotyping are highlighted as key drivers shaping the future of ornamental plant improvement.