Evidence for the occurrence of unreduced gametes in interspecific hybrids of Hibiscus

Interspecific crosses within Hibiscus resulted in F(1) and F(2) (self-pollination of F(1)) progeny of H. syriacus x H. paramutabilis. Of these populations, seven F(1) and five F(2) hybrids were analysed for the occurrence of unreduced gametes. Pollen from H. syriacus, H. paramutabilis, and the F(1) and F(2) hybrids had diameters between 80 - 230 mu m. However, two of the F(2) hybrids tested also had a few pollen grains (< 1%) with a diameter of 250 mu m. Flow cytometry and a study of meiosis in the pollen of these two F(2) hybrids revealed that 6 - 10% unreduced pollen was produced. Both the parent plants, H. syriacus 'Oiseau Bleu' and H. paramutabilis, and all of the F(1) hybrids were tetraploid, with a genome size between 2.32 - 2.48 pg 1C(-1). However, all five F(2) hybrids were hexaploid, with a genome size between 3.49 - 3.59 pg 1C(-1). Since no unreduced pollen could be detected in the F(1) H. syriacus x H. paramutabilis hybrids, either by flow cytometry or by a study of meiosis in the pollen, it could be concluded that the F(1) hybrids must produce unreduced egg cells

Publication year:2009

Keywords:AGRICULTURE, Belgium, CELLS, CROSS, CROSSES, FLOW, Flow cytometry, FLOW-CYTOMETRIC ANALYSIS, FLOW-CYTOMETRY, genome size, Hibiscus, HYBRID, HYBRIDIZATION, HYBRIDS, interspecific hybrids, meiosis, Nuclei, Occurrence, PARAMUTABILIS, PLANT, PLANTS, POLLEN, POPULATION, POPULATIONS, PROGENIES, Progeny, SINOSYRIACUS, SIZE, SYRIACUS, tetraploid, Unreduced gametes