(43(2):123-134)水稻劍葉長與寬之遺傳

Since some distinguished differences in leaf characteristics were observed between the modern U. S. and oriental rice cultivars and leaf length and leaf width are remarkable leaf characteristics in modern rice breeding programs, a series of genetic studies was designed to tackle the genetic control of leaf characteristics for expanding the genetic diveristy. Genetic information about leaf length and width of flag leaf reported here was deduce by the components of variation and the ratios between components and diallel graph from a six-parent diallel cross of rice, according mainly to theory and analysis of diallel cross of Hayman. Results clearly indicated that both additive and dominance gene effects were important in differentiating the two flag leaf characteristics; however, it is evident that the genetic mechanisms of two characteristics studied were different. As to leaf length, dominance gene effects was significantly greater than those of additive, the overall measure of dominance of leaf length was overdominance, and the direction of dominance was ambidirectional. On the other hand, dominance gene effects on controlling leaf width was unimportant than additive gene effects, the mean degree of dominance of leaf width was partial or incomplete, and the direction of dominance was toward relatively wider flag leaf.鑒於美國稻與東方稻葉部性狀互有不同暨葉部性狀為現代水稻育種計畫中極重要之性狀，為擴大種原利用，一系列關於稻葉部性狀之遺傳研究已展開。本報告以包含美國稻與東方稻等六個水稻種原之全互交材料經藉Hayman氏之全互交理論及方法探討參試稻種原劍葉之長與寬的遺傳行為。所得數據推論出該兩性狀雖受累加性基因及顯性基因所同時控制，但此兩性狀之遺傳機制則不盡相同。就劍葉之葉長而言，顯性基因效應顯著地大於累加性基因效應，平均顯性程度屬超顯性，顯性方向則呈兩向顯性。另方面，劍葉葉寬之遺傳機制則累加性基因效應顯著地大於顯性基因效應，平均顯性程度屬部分或不完全顯性，顯性方向則趨向寬劍葉者