investigation the effects of cold and starvation stresses on viability and cell division of microspores in rosa hybrida l.

in this research, the isolated microspore culture system in 15 rose cultivars was tested. in the first experiment, the effect of rose cultivars on microspore viability and multicellular formation was examined. results showed that the most multicellular structures obtained in ‘apollo’, ‘amarosa’, ‘majic’, ‘candy’, ‘exotic’ and ‘velvet’ varieties. in the second experiment, the effect of various induction media i. e. tmg and at3 with different carbohydrate sources (maltose, glucose and sucrose) with or without lactalbumin hydrolysate on microspore embryogenesis was tested. the highest percent of microspore viability and multicellular formed in at3 medium contained glucose and lactalbumin hydrolysate. in the third experiment, the effect of temperature stresses (25 °c, 4 °c for 14 days and 30 °c for 7 days) on microspore viability and multicellular formation was tested. the most microspore viability obtained at 25 °c treatment, but the highest microspore multicellular formed in stress treatments. in the fourth experiment, the effect of sugar starvation on microspore embryogenesis was assessed. starvation treatment in ‘amarosa’ for 3 days at 4 °c caused to microspore embryogenesis. this is the first report of microspore embryogenesis in rose, however, embryos could not regenerate.