Azide mutagenesis in rice

Abstract

Seeds of rice cultivars viz Jaya, IET 5656 and Fujiminori presoaked for 24 h were treated with 0·001, 0·002, 0·004 and 0·005 molar concentrations of sodium azide at pH 3 for 4 h with a view to investigate its mutagenic action in rice. The percentage of germination, survival, seedling height and leaf number decreased in the treated population with a few exceptions. Cytologically abnormal plants were not detected in any of the treated population. Plant height, panicle branches, seed set and panicle grain weight decreased in the azide treated population whereas tiller number increased in Jaya and Fujiminori cultivars. The frequency of chlorophyll mutants induced was more in Jaya less in IET 5656 and the least in Fujiminori 0·005 molar concentration was found to be the most effective for inducing chlorophyll mutations in IET 5656 and Fujiminori. The same concentration induced more morphological mutants in all the 3 cultivars. Morphological and physiological mutants isolated include the tall, semidwarf, dwarf, early and late flowering mutants, protein rich mutants, grain shape mutants and many others. Varietal differences are indicated in the induction of seedling injury and of chlorophyll and morphological mutants produced.