Recovery or increase of induced genetical effects dependent upon the moisture content of stored N-methyl- N-nitrosourea-treated barley seeds

Abstract

( 1) Barley seeds were treated with N-methyl- N-nitrosourea (MNU) and stored at 25° with 30% moisture. A strong recovery was observed of the M 1 seedling height and chromosome aberrations in root tips and of the M 2 chlorophyll mutant frequency. ( 2) In contrast, storage of MNU-treated seeds with 20% moisture led to a pronounced increase in biological injury. ( 3) After storage of MNU-treated seeds with 15% moisture, a small recovery in seedling height and in chromosome aberrations took place, but there was no significant change in frequency of the M 2 chlorophyll mutants. ( 4) Storage of MNU-treated seeds with 5% seed moisture had no significant effect on either type of biological injury in the M 1 generation or the M 2 chlorophyll mutant frequency. ( 5) Storage effects of MNU and ethyl methanesulphonate treatments of barley seeds are compared.