Two Desynaptic Mutants of Rhoeo spathacea (Commelinaceae).

Abstract

Two desynaptic plants causing dissociation of pairing chromosomes were found among plants collected in wild populations of Rhoeo spathacea.One of those plants is of the spathacea variety and was identified as GAVA YT-1, while the other was found to be of the concolor variety and was identified as GAVA C-2. Both plants were found to be diploids with 2n=12 and displayed 2 cytotypes: 9m +3sm and 4m +8sm, respectively.GAVA C-2 is the first desynaptic plant observed of the concolor variety. The mutant plants formed univalents in all PMC at MI. GAVA YT-1 formed 12 univalents in 84.9% of PMC and 89.7% in PMC of GAVA C-2. Microspores from GAVA YT-1 had chromosome from n=5 to n=12, and microspores produced by GAVA C-2 showed n=8 to n=18.The GAVA C-2 plant produced 21.3% unreduced microspores. There were large differences in pollen stainability between the 2 desynaptics: GAVA YT-1 with 17.2% and GAVA C-2 with 55.5%.