EVIDENCE OF FUNCTIONAL UNREDUCED GAMETES IN TRIFOLIUM-REPENS L

The current research reports the first evidence of functional 2n gamet es in megaspores of Trifolium repens L. Reciprocal backcrossing of a c olchicine doubled hexaploid (2n = 6x = 48) T. repens x T. nigrescens ( 6x H-6909-5) F-1 hybrid to T. repens produced four seeds from 1700 pol linations. The backcross involving 6x H-6909-5 as the female parent an d T. repens as the male resulted in only one seed which was, as expect ed, a pentaploid (2n = 5x = 40) presumably carrying four genomes of T. repens and one genome of T. nigrescens. On the other hand, those back crosses which utilised T. repens as the female parent and 6x H-6909-5 as the male parent, resulted in 3 viable seeds. These were unexpectedl y all heptaploid (2n = 7x = 56) with presumably six genomes of T. repe ns and one genome of T. nigrescens. The occurrence of heptaploids from a T. repens x 6x H-6909-5 (4x-6x) cross can only be explained by the union of n (= 3x = 24) pollen from 6x H-6909-5 with 2n (= 4x = 32) egg s from T. repens.