Pollen Shedding Pattern, Viability, and Longevity of Seashore Paspalum.

A clearer understanding of the reproductive biology of seashore paspalum is needed to design improved production systems for seeded cultivars.  A series of greenhouse and field studies were conducted to determine the daily shedding pattern, viability, and longevity of S. paspalum pollen. An airborne particle counter (Handheld 5016, Lighthouse Worldwide Solutions, Fremont, CA) was used to document daily shedding pattern in a field setting. An optimized liquid germination medium consisting of 21% (w/v) sucrose, 0.62 g l^-1 Ca(NO₃)₂ ∙ 4 H₂O and 0.24 g l^-1 boric acid was developed to effectively assess pollen viability. Longevity was estimated by inoculating pollen onto germination medium every 20 min for at least 180 min. Longevity response to storage temperature was also tested at 15, 20, 25, 30, 35 and 40 C^o. Pollen release occurred between 0700h to 1100h with peak release between 0730h to 0900h.  The average germination rate of pollen collected at 0730h was 72% under room temperature. Only 50% of the pollen remained viable at 30 min and pollen completely lost viability in 120 min. Among the temperatures tested in this study, pollen stored at 15°C survived the longest. Our results establish that pollen of seashore paspalum is viable but is released during a short period of time and has a short longevity that is negatively impacted by high temperatures.