4 NOVEL TELOANEUPLOIDS OF PLANTAGO-LAGOPUS L

A cross was made between a disomic (2n = 12) and a primary trisomic (2 n = 12 + 1) of Plantago lagopus in 1986. In the progeny obtained from the cross, one offspring carried a small telocentric chromosome in add ition to the standard complement of 12 chromosomes. The additional chr omosome is unique; it does not match any chromosome or chromosome arm of the standard complement in morphology. The teloaneuploid was selfed , and over a period of 5 years, plants with two, three, and four addit ional telocentric chromosomes have been raised. The behavior, transmis sion, and effects of these additional chromosomes are described.