Sodium azide mutagenesis in diploid and hexaploid oats and comparison with ethyl methanesulfonate treatments
Abstract
Sodium azide was tested as a mutagen in a diploid oat, Avena strigosa L. (2 n = 2 x = 14), and in hexaploid cultivated oats, A. sativa L. (2 n = 6 x = 42). Optimized treatments of a 1-hr exposure of diploid oat seeds to 2-10 mM azide at pH 3 or 4.5 after a 4-hr water presoak gave frequencies of chlorophyll deficient mutants in progeny populations similar to those from EMS treatments of 50-70 mM EMS for 4 hr after an 8-hr presoak. In the diploid oat, for each mutagen about 60% of the M 1 generation plants grown from mutagenized seed had mutants segregating among their M 2 generation progenies. In contrast, in the three hexaploid cultivars tested only 1-2% of M 1 plants gave mutant progeny following treatments with azide and 2-4% with EMS. On a total M 2 plant basis the frequency of chlorophyll deficient mutants was <0.3% in the hexaploid oats compared to 3-5% in the diploid oat. The lower frequency of mutants in the hexaploid vs diploid oats could be accounted for by the presence in hexaploids of duplicative loci masking the effects of mutation at individual loci. Mutants with either meiotic synapsis deficiency, shorter plant height, or possible male sterility were recovered in hexaploid oats following azide mutagenesis. Their recovery indicates that azide mutagenesis can be effective in cultivated hexaploid oats although the overall frequency of mutant recovery may be low compared to that obtained in a diploid species.
- Publication:
-
Environmental and Experimental Botany
- Pub Date:
- 1985
- DOI:
- 10.1016/0098-8472(85)90043-7
- Bibcode:
- 1985EnvEB..25....7R