Evaluation of Pollination Potential in ‘Jinfeng’ Kiwifruit Seedling Male Plants Based on Floral Traits and Pollen Viability

This study systematically assessed floral phenotypic traits, pollen viability, and ultrastructure in 120 male progeny of Actinidia chinensis ‘Jinfeng’. We documented floral features, measured pollen viability using Alexander staining and germination tests, and analyzed pollen morphology through scanning electron microscopy. Correlation analyses examined relationships between pollen viability and floral or pollen morphological traits. Results showed uniform qualitative floral traits but significant variation in quantitative traits. Pollen viability ranged widely (0.3–100%, CV = 43.60%) with consistent outcomes across assessment methods. Pollen grains were mainly prolate to perprolate with three germination furrows, polar axis length (P) ranged from 25.34 to 34.62 μm, equatorial axis length (E) ranged from 11.72 to 16.17 μm, and colpus length ranged from 20.6 to 30.58 μm. Viability was not correlated with quantitative floral traits or anther color but was significantly positively correlated with the polar/equatorial diameter ratio (P/E ratio, r = 0.622), indicating higher viability in perprolate pollen (P/E > 2.0). This study highlights significant genetic diversity in ‘Jinfeng’ male progeny and establishes a relationship between pollen morphology and viability in kiwifruit, providing a theoretical and practical basis for male selection and a foundation for pollen morphology research.