EFFECTS OF TEMPERATURE ON POLLEN VIABILITY AND STIGMA RECEPTIVITY IN E. JAPONICA '¿DAWUXING'

A series of experiments were carried out to determine the effects of temperature on pollen viability and stigma receptivity in E. Japonica ‘Dawuxing’. Flowering shoots of ‘Dawuxing’ loquat were held at temperatures ranging from 5 to 30°C. At low temperature (5°C), blooming and pollen grain dehiscence were delayed, but pollen viability was relatively high (55%) up to the 7th day, and ovule viability exceeded 90%. Blooming and pollen grain dispersion were promoted at temperature of 25-30°C, resulting in faster pollen germination but decreased stigma receptivity and viability (6.39%) of pollen grains cultured at 30°C, 7 days after anthesis (DAA). Stigma receptivity decreased in flowers at 30°C and 3 DAA, and there was no stigma receptivity at 5 DAA. These results indicated that flowers at the balloon stage might achieve pollination and fertilization upon weather improvement after cold and wet conditions.