Floral Color Segregation and Quantitative Morphological Variation in Miniature Phalaenopsis Hybrid Populations

Abstract

The simultaneous improvement of multiple ornamental traits remains a major challenge in Phalaenopsis breeding, and the relationship between floral color phenotypes and quantitative morphological traits is poorly understood. Four hybrid populations of miniature Phalaenopsis were evaluated for floral color segregation and quantitative morphological variation. All hybrid populations derived from white-flowered parental lines segregated into two floral color phenotypes: pink flower with pink labelum (PP), an unexpected phenotype absent from all parental lines, and white flower with yellow labelum (WY), resembling the common parent. χ 2 analysis indicated that segregation ratios did not differ significantly from a hypothesized 1:1 ratio in all populations. Principal component analysis (PCA) revealed no clear clustering between WY and PP progeny based on quantitative morphological traits. Although different parental combinations produced distinct multivariate distribution patterns, PC1 was primarily associated with plant size-related traits, and PC2 was mainly associated with multiple-flowering traits in all populations. These results highlight the potential of combining distinct floral color, desirable plant size, and multiple-flowering characteristics through different parental combinations, providing useful information for future miniature Phalaenopsis breeding.