Hybridization Efficiency and Genetic Diversity in Cut Chrysanthemum: Integration of Morphological and iPBS Marker Analysis

Abstract

The increasing demand for novel cut chrysanthemum cultivars has underscored the significance of precision breeding techniques, with particular emphasis on hybridization and molecular tools. This study aimed to assess the cross-compatibility of selected chrysanthemum cultivars and to evaluate the genetic, quantitative, and qualitative diversity among the resulting F1 progenies. A total of six hybrid combinations were generated using five commercial parental cultivars. Ploidy levels were determined via flow cytometry and chromosome counting, confirming that all parents were allohexaploid (2n = 6x = 54). Pollen viability and germination rates varied significantly among male parents, influencing hybridization success. A total of 30,391 seeds were obtained, with germination rates ranging from 2.69% to 10.73%, depending on the cross combination. F1 progenies showed considerable phenotypic variability in flowering time, flower stalk length, flower diameter, and branch weight. Molecular characterization using eight iPBS primers revealed a high polymorphism rate (93%) with a mean Polymorphism Information Content (PIC) value of 0.614, confirming substantial genetic diversity among genotypes. Cluster and principal coordinate analyses demonstrated that most F1 genotypes grouped closely with their maternal parents, although unique genomic variations were also detected. The integration of morphological and molecular data provides valuable insights for selecting superior genotypes and optimizing breeding strategies. This study highlights the importance of evaluating hybridization potential and genetic diversity in the development of commercially viable cut chrysanthemum cultivars.