In vitro pollen germination and tube growth in water chestnut

An optimal medium for in vitro pollen germination and tube growth in Japanese (T. japonica Flerov) and Chinese (Trapa bicornis L.) water chestnuts has been standardized. A medium containing 25 % sucrose, 75 ppm boric acid and 300 ppm CaCl2.2H2O gelled with 1% agar, pH 6.0, was optimal for germination of fresh pollen and pollen tube growth in both species. Flower age, pH of culture medium and agar concentration, culture incubation temperature were important factors. Lower incubation temperatures (15°-20°C) were better for tube elongation, but higher incubation temperatures (25°-30°C) elicited the highest germination percentage.