EFFECT OF TEMPERATURE IN CARPEL MATURATION AND MISSHAPEN FRUIT IN STRAWBERRY

This research was carried out in order to know about the effect of low temperature on strawberry carpels maturation and finally the obtaining of misshapen fruit. Two groups of 20 strawberry plants (cv. ‘Camarosa’) were put down to temperatures of 22 or 7°C with a photoperiod of 11h light/13h dark. Then, five flowers at different development stages: 4, 3, 2, and 1 days before anthesis and 1, 2, 3, 4, 5 and 7 days after anthesis were chosen and pollinated. 24 hours later, in each case, carpel maturation was estimated. Results showed differences in the carpel maturation under different culture conditions, and according to carpel position (apical or basal) in the receptacle. In plants put down to 7°C, 100% of the apical stigma of flowers in stage two days before anthesis was immature. In the same phenologic stage, all the apical stigmas of flowers of plants put down to standard temperature (22°C) were basically mature. Different stigma maturation rate between apical and basal carpels was observed. In general, we found that in apical stigma, maturation was slower than in basal stigma. The slowest maturation occurred in apical stigma at 7°C. Percentage of misshapen fruit developed from hand-pollinated flowers varied depending on the flower maturation stage. Pollinated flowers, until one day before antesis stage, tended to produce misshapen fruits.