Comparative Floral Fertility in Heat Tolerant and Heat Sensitive Tomatoes1

Abstract

The heat tolerant tomatoes (Lycopersicon esculentum Mill.) breeding line AU 165 and ‘Nagcarlang’ were compared with the heat sensitive ‘Floradel’ in fruit set, pollen abortion, and embryo sac abortion. The 2 heat tolerant cultivars had a significantly higher percentage fruit set under both moderate and high temperature in spring and summer than did ‘Floradel’, but fruit set of all 3 cultivars was significantly lower at high temperature. The fruit set of all 3 cultivars was markedly improved by hand pollination, indicating that insufficient pollination probably was a major cause of heat sterility at high temperature. Both pollen and embryo sac abortion were minor factors in the reduced fruit set observed. Heat tolerance in the cross AU 165 × ‘Floradel’ appeared to be partially dominant.

Influence of Temperature and Plant Water Status on Pollen Viability in Beans

“…An especially stress-sensitive period occurs at the time of pollination/ fertilization (18). Although the entire gynoecium of plants is responsive to fluctuations in temperature and plant-available moisture, the male gametophyte (pollen) is usually more sensitive than the female gametophyte (3,13). The stage of plant Received for publication 13 Nov.…”

“…Since acreage of cucurbits is limited, there is little interest in developing or registering new chemicals for cucurbit use. Current limited recommendations (3,13,16) include restricted and high-cost herbicide alternatives that are considered inadequate (5,14,21).…”