Effect of temperature on seed set and in vitro pollen germination in French beans (Phaseolus vulgaris)

Abstract

A technique for in vitro germination of French bean pollen was developed and the effect of temperature on gamete development, pollen germination and seed set investigated. Temperature had a profound effect on in vitro pollen germination percentage, pollen tube growth and bursting percentage. These were maximal at 7.2°C, 16.7°C and 38.3°C, respectively. In this study, pollen development was not affected at day/night temperatures of 16.1°/12.8°C, and ovule abortion was the cause of seed set failure at these temperatures. Hot water treatment (48°-44°C) of flowers caused failure of seed set due to pollen inviability. Consequently this technique may allow hybridization without emasculation in beans. Treatment of buds with hot water of different temperatures and in vitro pollen germination at high temperatures may have application as screening techniques for heat tolerance in French beans.