Effect of temperature on pollen tube kinetics and dynamics in sweet cherry, Prunus avium (Rosaceae)

prevailing ambient temperature during the reproductive phase is one of several important factors for seed and fruit set in different plant species, and its consequences oil reproductive Success may increase with global warming. The effect of temperature oil pollen performance was evaluated in sweet cherry (Prunus avium L.), comparing as pollen donors two cultivars that differ in their adaptation to temperature. 'Sunburst' is a cultivar that originated in Canada with a pedigree of cultivars from Northern Europe, while 'Cristobalina' is a cultivar native to southeast Spain. adapted to warmer conditions. Temperature effects were tested either in controlled-temperature chambers or in the field in a plastic cage. In both genotypes. all increase in temperature reduced pollen germination. but accelerated pollen tube growth. However, a different genotypic response, which reflected the overall adaptation of the pollen donor. was obtained for pollen tube dynamics, expressed as the census of the nicrogametophyte population that Successfully reached the base of the style. While both cultivars performed similarly at 20degreesC. the microgametophyte population was reduced at 30degreesC for Sunburst and at 10degreesC for Cristobalina. These results indicate a differential genotypic response to temperature during the reproductive phase, which could be important in terms of the time needed for a plant species to adapt to rapid temperature changes.