Exploring the Floral Biology of Salix alba: Insights into Reproductive Dynamics, Pollen Production and Pollen Morphology in Kashmir Himalayas

This study investigates the floral phenology, pollen production and pollen characteristics of Salix alba (white willow) over the years 2022 and 2023, highlighting inter-annual and individual tree variations. In 2022, male catkins began flowering between March 8 and March 10, while female catkins initiated between March 14 and March 22. Flowering for male catkins lasted until mid-May and for female catkins until late May. In 2023, male catkins started flowering from March 10 to March 14 and female catkins from March 17 to March 24, with similar flowering durations. Inflorescence diameters varied among individual trees, ranging from 4.4 mm to 7.7 mm for male catkins and 6.1 mm to 8.1 mm for female catkins across the two years. Pollen production exhibited significant variability with the highest recorded at 4,600,995,000 grains per tree and the lowest at 498,312,500 grains per tree. On average, trees produced approximately 2,164,836,667 pollen grains. Pollen viability ranged from 75% to 80%, with sizes between 16 µm and 26 µm. The pollen-ovule ratio also showed substantial differences, with the highest ratio observed at 7600:2 and the lowest at 2345:7. These findings underscore the considerable year-to-year and tree-to-tree variation in the reproductive traits of Salix alba, which may have implications for its breeding and conservation strategies.