The effect of temperature on pollen germination and pollen tube growth of quince cultivars

The effect of three different temperatures (8, 16 and 24 degrees C) on pollen germination and pollen tube growth in vitro in eight quince cultivars ('Leskovacka', Vranjska', 'Morava', 'Pazardzijska', 'Hemus', 'Asenica', 'Portugal' and 'Triumph') was studied. The research was carried out in a two-year period (2015-2016). Germination rate and pollen tube growth were determined on the culture medium containing 15% sucrose and 0.7% agar. The temperature showed a significant effect on in vitro pollen germination and pollen tube length. The lowest pollen germination was determined at the temperature of 8 degrees C (22.73%). However, pollen germination was three times higher at temperatures of 16 and 24 degrees C (62.60 and 72.16%, respectively). The temperature effect was significantly more pronounced on the pollen tube length. The smallest pollen tube length was determined at 8 degrees C (241.5 mu m) and it was four to five times lower than the pollen tube length measured at 16 and 24 degrees C (809.6 and 1137.4 mu m, respectively). On this basis, it can be concluded that the temperature of 8 degrees C was not sufficient for pollen germination and pollen tube growth in quince cultivars. However, temperatures of 16 and 24 degrees C were optimal for pollen germination and pollen tube growth.