CHIASMA FREQUENCY AND DISTRIBUTION IN A MAIZE FAMILY SEGREGATING FOR K10 AND TRISOMY 10

E. J. Ward ¹

¹ Department of Plant Science, University of Manitoba, Winnipeg, Canada R3T 2N2

Chiasma frequency was determined from total chiasma counts, and the distribution of these exchanges was determined by the ratio of proximal to distal chiasmata. No effect of trisomy 10 could be demonstrated. Confirmation was obtained of earlier work showing more proximal and fewer distal chiasmata in K10 plants than in controls. However, diakinesis data failed to confirm the ability of K10 to increase total chiasmata as suggested from metaphase I results.