Nuclear variation withinAvenae

The amount of DNA per nucleus and the dry mass of isolated nuclei does not vary significantly between the six diploid species investigated. No differences were found either between tetraploid species or between hexaploids. Between the diploids, tetraploids and hexaploids taken as groups there was respectively a 1, 2 and 3 ratio maintained for the amount of DNA. For chromosome volume significant differences were found between the tetraploids but not in 2x or 6x series. Correlations are shown between chromosome volume, nuclear DNA content and nuclear dry mass. In polyploids the nuclear dry mass is less than expected from the values obtained for the diploids.Contribution No. 20 from the Canada Agriculture Research Station, Ste Foy, P.Q.