Variation of Agronomic Traits of Rice Mutant Lines Induced by Sodium Azide

摘要

To investigate the mutagenecity of sodium azide (SA) and to select mutants having various agronomic characteristics in rice (Oryza saliva L. ssp. japonica), dry seeds of rice variety 'Suweon 472' were treated with 0, 0.5, 1.0, 2.0, and 4.0 mM SA solutions prepared in 0.1 M phosphate buffer (pH 3.0). Germination rate, seedling height and sterility were investigated in MI generation and chlorophyll mutations were observed in Ms generation. Germination rate and seedling height decreased as the increaseof SA concentration in MI generation, the maximum seed sterility (40.8%) was found at 4.0 mM SA concentration. Chlorophyll mutants were occurred in Ms generation and the frequency calculated on a line basis was 13.5% at the same treatment. Many kinds ofmutations for morphological and agronomic characters were observed and mutations with short culm and glabrous leaf were frequently found in Ms generation. Interestingly, five mutant lines resistant to blast or bacterial blight (BB) were selected and evaluated with several isolates in Ms generation although Suweon 472 has been known to be susceptible to blast and BB. These mutants showed all resistance to seven isolates of blast and a total of 76 lines among 2,567 lines evaluated showed resistant to raceKl of bacterial blight. Two mutant lines (440172 and 41272) showed different reaction to BB isolates from the other resistant mutants. A few kinds of endosperm mutants were also identified and most of them were waxy mutants.