Floral biology, pollen morphology and reproductive behaviour of three tropical Nymphaea cultivars
Assistant Professor (Horticulture), Instructional Farm, Kerala Agricultural University, College of Agriculture, Vellayani, Thiruvananthapuram, 695522, Kerala, India. Corresponding e-mail: sheena2sa@kau.in
DOI: https://doi.org/10.37855/jah.2026.v28i01.2
Full text PDF A study was conducted to examine the flowering phenology, floral biology, and pollen morphology of three tropical Nymphaea cultivars, viz. ‘Blue Whistle’, ‘Carla’s Sonshine’, and ‘Poonsup’ under Kerala conditions. Anthesis behavior varied significantly among cultivars and across seasons, with flowers opening between 07:00 and 09:15 h and closing between 16:00 and 18:15 h. Temperature exerted a more decisive influence than light intensity, resulting in extended anthesis during cooler months (November to February) and shortened durations during the monsoon (June to October). All cultivars were protogynous, exhibiting a female phase on the first day and a male phase over the following three days. Stigma receptivity lasted for 22-25 h and showed cultivar-specific variation in cup diameter and number of appendages. Pollen fertility ranged from 42.16 % to 80.92 %, with ‘Poonsup’ recording the highest viability. Scanning electron microscopy revealed oblate-spheroidal, medium-sized, zonosulcate, and psilate pollen grains consistent among cultivars. The results highlight the combined influence of genetic and environmental factors on reproductive behavior in Nymphaea and provide valuable insights for breeding programs aimed at enhancing floral longevity, fertility, and ornamental potential in tropical waterlilies.
