THE USE OF NITROUS OXIDE FOR PRODUCING EUPOLYPLOIDS AND ANEUPLOIDS IN WHEAT AND BARLEY

Abstract

The use of N 2 O as a polyploidizing agent in barley and wheat proved to be effective in both species when applied in the interval from 4 to 24 hr after pollination in barley and 24 to 48 hr after pollination in wheat. When treated in these intervals with four atmospheres pressure, 75% of the barley and 54% of the wheat embryos were polyploid. There was a marked difference between the two species in the proportion of aneuploids produced. In barley 5% of the treated embryos were aneuploid whereas 42% of the wheat embryos were aneuploid in the critical treatments.Evidence is presented to show that most of the aneuploids originated from disturbances in the anaphase distribution of chromosomes or from a scattering of chromosomes before the formation of restitution nuclei rather than from multipolar divisions.A potential use of N 2 O for producing homozygous diploid plants of Hordeum vulgare L. emend Lam. from crosses between Hordeum vulgare and H. bulbosum L. is discussed.