Aneuploidy in induced autotetraploid populations of Festuca pratensis, Lolium multiflorum and Lolium perenne

Abstract

Frequencies of aneuploids were determined in three induced autotetraploid populations of Lolium, two of L. multiflorum, and one of L. perenne. Vegetative and generative properties of euploids, hypoploids, and hyperploids grown as spaced plants were studied. Before chromosome counts, the seed lots were sieved into five seed size fractions. Chromosome numbers were determined by a modification of conventional root tip squash. The total aneuploid frequency in Lolium multiflorum, Sv 02054 was 52.6%, in Sv 02056 50.7%, and finally in Lolium perenne, Sv 01413, the total aneuploid frequency was 41.9%. There are no or only weak relations between seed size and chromosome number in these populations. Among the aneuploid chromosome classes, the hypoploid was the largest one in all fractions in the three populations Vegetative and generative characters were measured. Significant negative effects of aneuploidy were only found in the generative characters There were no significant differences in heading time between chromosome classes in either of the populations.