In vitro manipuilation of cucumber (Cucumis sativus L.) pollen and microspores:: Isolation procedures, viability tessits, germination, maturation

In vitro germination of isolated pollen grains and maturation of microspores are needed for several biotechnological manipulations of cucumber pollen. The present study was focused on establishing optimal conditions for monitoring isolation, sterilization and viability. Germination of mature cucumber pollen and maturation of microspores were attempted. Five protocols for testing pollen and microspore viability were tested and three were studied in detail. The viability of fresh or artificially, damaged grains was tested using aniline blue in lactophenol, fluorescein diacetate (FDA) and 2,5-iphenyl tetrazolium bromide (MTT). For strong contrast, simple manipulation and non-fluorescence, MTT was found to be the most suitable. Pollen was efficiently isolated by shaking chopped anthers in germination media. Germination of isolated pollen was achieved for the first time using this procedure. The highest germination rate was obtained using 90.4% maltose in germination media at pH 7.0. Using a similar isolation method, microspores cultured on four selected maturation media showed relatively high viability (up to 29.1%) which was not affected by the sterilization procedure, although mature pollen grains did not form.