Accessory Chromosomes in Secale and Poa

KDINARY rye, Secale cereale, is a diploid cereal with 1 4 0 chromosomes, but plants with a small extra pair have also been observed occasionally in populations in various countries. The first rye plants with 1 6 instead of 1 4 chromosomes were observed about 25 years ago, in Belgium by FERRAND and in Japan by KIHARA and GOTOH. Later on such plants were discovered also in the U. S. A,, Russia, Sweden, Bulgaria, and England. I a m working with material of this kind derived from two different Swedish rye varieties.