Abstract:To explore the diversity of floral organ phenotypic traits in tulip germplasm resources, 60 tulip cultivars were used as experimental materials. Principal component analysis and cluster analysis were performed on 9 floral organ phenotypic traits to study the genetic diversity of their floral organ phenotypic traits, providing reference for the evaluation, identification, and utilization of tulip germplasm resources. The results showed that there were varying degrees of differences in 5 quantitative traits (corolla longitudinal diameter, corolla transverse diameter, stigma length, stigma circumference, and stigma diameter) and 4 quality traits (corolla main color, pollen color, stigma shape, and initial flowering period). The coefficient of variation of corolla longitudinal diameter is 19.35%, and the coefficient of variation of corolla transverse diameter is 23.41%. The range of variation between cultivars is relatively large, and the degree of dispersion is relatively high. However, in terms of stigma length, circumference, and diameter, the range of variation is small, and the distribution is concentrated and the degree of dispersion is relatively low. 91.67% of the tested varieties have a triangular prism shaped stigma, and 5 cultivars exhibit variation in stigma shape. According to the observation of the initial flowering period, the proportions of early flowering, middle flowering, and late flowering in the tested cultivars are 20%, 38%, and 12%, respectively. Principal component analysis extracted 5 principal components that can reflect the phenotypic traits of tulip flower organs, with a cumulative contribution rate of 85.179%. By constructing a comprehensive evaluation model for the phenotypic traits of tulips, a total of 12 cultivars were found to have a comprehensive score (>0.5). Among them, 'Candy Prince' and 'Foxy Foxtrot' scored the highest, belonging to the two pink mid flowering cultivars. The stigma was long and thick, and the comprehensive traits of the flower organs were excellent. Principal component clustering analysis was conducted on 9 phenotypic traits of flower organs in 60 tulip cultivars, which can be divided into 4 categories. The 51 cultivars in the first category are mainly tulip cultivars with larger and more colorful flower types, thicker stigma, and excellent comprehensive performance of flower organ traits; The second type is only one variety of 'Purple Dream', characterized by a slender corolla and thick and long stigma in the floral organs; The third category gathers 6 cultivars with short stigma and average comprehensive performance of floral organ traits; The fourth type is two cultivars with variations in stigma shape. The research results can provide support for the classification of tulip cultivars and the evolution of their phylogenetic relationships from a morphological perspective, and provide reference basis for further development of excellent floral organ ornamental traits, germplasm innovation, and variety improvement of tulips.