Chiasma Formation in a Heteromorphic Bivalent in Belamcanda chinensis, Leman

In course of cytological investigation a heteromorphic pair of chromosomes was observed in one of the plants Belamcanda chinensis growing in the garden.The pairing behaviour of the heteromorphic pair was studied in detail from the onset of meiosis.At diplotene one chiasma was invariably observed in the heteromorphic arm of this bivalent but at metaphase I in many cases this bivalent did not show any chiasma in that arm, presumably the chiasma has slipped off.The frequency of reductional and equational separation studied at anaphase I conformed to the Mather's formula for n=1.The diplotene configuration of this bivalent supports the partial chiasma type theory of crossing over.