Screening Tomato for High-temperature Tolerance Through Pollen Viability Tests

A study was undertaken to determine a) if genotypic responses for fruit set and pollen viability in tomatoes ( Lycopersicon esculentum Mill.) exposed to high temperatures are related, and b) if pollen viability at high temperature could be used to screen tomato plants for better performance in high-temperature environments. Fruit set, pollen germination, and pollen tube length varied among tomato sources exposed to 40C for 60 min, and both pollen germination ( r = 0.988***) and pollen tube length ( r = 0.815**) correlated positively with fruit set. Differentiation among tomato sources for increased pollen viability at high temperature was accelerated by increasing the temperature at which flowers were exposed from 40 to 48C. Pollen viability has a major role in determining the fruit set of tomatoes at high temperatures and can serve as a basis of screening for tomato plants that will potentially produce higher fruit yield in high-temperature environments.