The use of genetic resources in rose breeding and creation of new rose cultivars through hybridization and selection

Despite the existence of more than 37,000 different varieties of roses worldwide, there remains a significant interest and high relevance in rose breeding. The rose is the most beloved flower in the world, commonly named the “queen of flowers”. In addition to its remarkable ornamental significance, the rose possesses various ecological, environmental, landscaping, food, pharmaceutical and medicinal, cosmetic, and industrial attributes, among others, thereby contributing to its overall socio-economic value. The current study investigated the results of rose breeding in a horticulture research center in the northwest of Romania with over 70 years of experience. The main method used to generate variability for the selection of new genotypes was artificial hybridization. After 1970, an average of 15-20 crossings per year were carried out, in different parental formulas or types of crosses, with approximately 1000-2000 flowers per pollinated per parental combination. Thousands of F1 hybrids were obtained annually (approximately 10,000-12,000 hybrids per year per hybrid combination), and dozens of elites were selected, grafted, and promoted as clonal selections in comparative trials. The success rate in obtaining new varieties through hybridization was 5.1% from total hybrid combinations, 0.72% from total hybrids, and 1.6% from total clonal selections. Of the total new varieties, hybrid teas represent 11.9%, floribundas 64.2%, shrubs 16.6%, and others 7.1%. 38 new cultivars suitable for open field cultivation were obtained, showing different habits, decorative value, flowering behavior, flower color, fragrance, resistance to frost or major diseases, and intended use. The exploration of new research directions aimed at harnessing the potential of roses, the region, and the socio-economic requirements was undertaken to enhance and beauty degraded, or landslide-prone lands, as well as to introduce damascene roses for the oil perfume and cosmetics industry.