(33(4):345-353)Mutagenic Efficiency of Sodium Azide on Rice Variety Tainung 67

在pH 3 的磷酸緩衝溶液中，以3 及6 小時二種處理時問和0.0、1.0 、1.5 及2.0 mM 四種濃度，探討疊氮化鈉對臺農67 號的種根長、萌芽出土率、幼苗高、結實率和存活率等之影響。結果處理時問對幼苗高之效果無顯著差異外，其餘性狀皆與處理時間和濃度呈顯著的負相關，其中種根長和存活率對處理濃度呈現二次曲線迴歸關係，餘三種反應對處理濃度呈直線迴歸關係。五種反應中，種根長和結實率之相關最高。本試驗結論建議：疊氮化鈉處理時間不宜太長，種根長和結實率可作為實用處理時間的指標。 The presoaked seed of rice variety Tainung 67 were treated with sodium azide for 2 time periods, 3 and 6 hrs, at 4 concentrations, 0.0, 1.0, 1.5 and 2.0mM in a pH 3 potassium phosphate buffer solution for mutation breeding. Five related traits at M1 generation were observed, they were seminal root length, germination rate in greenhouse, seedling height, seedset rate and survival rate [percentage of plants that bore one or more seeds]. Except the seedling height on time periods of treatment, there existed a significantly negative correlation regression of all traits on the time duration and concentrations of treatment. The regressions of seminal root length and survival rate on the concentrations showed a quadratic nature, while other traits, respectively, showed a linear regression on the treated concentrations. The highest correlation was found between seminal root length and seedset rate of M1 generation. It is suggested to use a relatively short time period of treatment and to use the seminal root length and seed-set rate of M1 plant as the indicator to eveluate the mutagenic efficiency of sodium azide in rice mutation breeding