Seed germination is a crucial stage in the life cycle of plants, and understanding the factors influencing germination is essential for successful cultivation, plant breeding, and conservation efforts. The genus Rosa, commonly known as roses, encompasses a diverse group of flowering plants renowned for their beauty and fragrance. Rosa germination is influenced by a variety of factors, including seed dormancy, environmental conditions, and seed treatments. Many Rosa species exhibit different types of seed dormancy, such as physical dormancy caused by hard seed coats and physiological dormancy due to internal mechanisms. Overcoming seed dormancy often requires specific treatments, including cold stratification, scarification, or chemical treatments, to promote germination. Environmental factors, including temperature, moisture, light, and substrate, play vital roles in Rosa germination. Temperatures ranging from 15 to 25 °C, moisture, and exposure to light or darkness, depending on the species, constitute suitable conditions for seed germination. Many studies have been conducted to investigate the germination requirements of different Rosa species, thereby expanding our understanding of their propagation and conservation. Additionally, advancements in techniques such as in vitro germination and molecular approaches have further enhanced our understanding of Rosa germination biology.

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.

Despite the abundance of rose varieties, it is necessary to create and use new genotypes to improve the appearance of green spaces and meet the demands of society, as well as to ensure their response to environmental variables and climate change. To assess the overall value and flower quality of several Romanian and foreign varieties under the ecological circumstances of Northwest Romania, 14 rose varieties from the shrub and floribunda groups were examined. The study identified notable variations among the cultivars for plant growth, foliage, flowers, and their susceptibility to the three primary fungal diseases (black spot, powdery mildew, and rust) prevalent in the study area. Additionally, the study identified the cultivars with proper resilience to frost during the five-year investigation period, particularly after the cold winters. New varieties obtained at HRS Cluj-Napoca, such as Cristiana, Pasiune mov, Maria-Cristina and Splendid, and international varieties such as Fisherman's Friend, Bonica and Mirato, stood out for their decorative quality and attractive floral elements. Some of these varieties have also been considered potential parents for disease and frost resistance in new hybridization projects. Broad-sense heritability data for the quantitative variables under investigation, as well as multivariate analyses, provided useful information for new rose breeding programs. The comparison of quantitative and qualitative assessments of important decorative traits for the roses, together with proper statistical calculation processes to assure their validity and trustworthiness, enabled the development of hypotheses or working models that can improve rose breeding efficiency.

Known as the “Queen of Flowers,” the rose is one of the most beloved flowers in the world. Although there are more than 37 000 cultivars of roses, novel forms must be created due to environmental and socioeconomic changes or advancements. An extensive knowledge of varietal variability is crucial for rose breeding, but the abundance of rose types and various estimating techniques sometimes hinder objective assessment. Different rose cultivars with varying features and fitness for use were evaluated in the current study, belonging to four groups: shrubs, floribundas, hybrid teas, and climbers. Based on the main traits of plant growth and vigor, flowers, foliage, and reaction to biotic and abiotic stress factors, it was computed the overall value, as a “general value” of tested cultivars and how the component elements (morphological traits or appreciate visually through notation) contribute to the ensemble of the ornamental and landscaping value. Valuable cultivars have been identified that deserve to be used in similar ecological conditions, or that can be recommended as potential parentals in new hybridizations (e.g. ‘Monica’ for the overall quality of the flowers and ornamental elements, ‘Pasiune in Mov’ and ‘Rosagold’ for fragrant flowers, ‘Perla Transilvaniei’ for intense flowering, and ‘Rosarium Utersen’ for durability of the flowers). In addition to the phenotypic evaluation, the genetic evaluation revealed information about the potential for hybridization using the cultivars as parents and the possibility of transferring the desired features to their offspring. Hypotheses were also issued regarding the use of appropriate statistics and multivariate analysis for the evaluation of quantitative or qualitative characteristics in roses and their relationships.