Polien viability in three Juniperus taxa

Abstract

Abstract Pollen viability in three Juniperus taxa native to Slovakia was investigated using in vitro germination test. The highest germination percentage and longest pollen tubes were surprisingly found in J. communis var.intermedia which is believed to be a putative hybrid between J. communis var. communis and J. sibirica. Germination rate of the hybrid averaged at 78.70% as compared with 64.96% and 60.83% of the pollen germination in the corresponding parental species. The same tendency holds for the pollen tube length reaching 38.68 µm in the putative hybrids, 31.39 µm in J. communis var. communis and 28.08 µm in J. sibirica. At the taxa level, the above given data were statistically highly significant in both pollen viability characteristics. Highest viability of J. communis var. intermedia pollen does not corroborate the widespread notion on reduced fertility of the plant interspecific hybrids. Additional tests are suggested to verify the hybrid nature of the putative hybrid population using DNA based population study and artificial crossing experiments involving the putative parental species J. communis var. communis and J. sibirica.