Pollen viability, germination, and seed setting of Nelumbo nucifera

Abstract

In tropical countries, low seed setting is a major problem when cultivating lotus (Nelumbo nucifera Gaertn.). This study determined seed setting in six wild lotus cultivars: Sai Rung (SR), Sam Roi Yot (SY), Klong Yong, Puttha Monthon (PM), Rachine (RC), and Nakhon Sawan (NW). In nature, the seed-setting rates range from 52-78%. From a stigma removal study, only a 53% seed-setting rate by self-pollination was recorded in the SR cultivar. This result was similar to the seed setting of self-pollinated PM, although high viability of PM pollen from day 2 full bloom flowers was observed. Self-incompatibility was studied in RC and NW cultivars. The indices of self-incompatibility of RC and NW were both 96% indicating that self-incompatibly affects low seed setting in these two cultivars. The results showed that the low seed-setting rate also came from seed abortion. A high value of self-incompatibility was observed in RC and NW cultivars, but not in the other cultivars studied.