Variation of Different Population of Tainan-White Maize in Taiwan

中文摘要 本研究從台灣不同地區（花蓮、桃園、台中、雲林、屏東、台東所蒐集之台南白族群，種植於台中地區以剔除環境因素影響，發現族群間農藝性狀之平均值有顯著之差異存在。以植株之營養性狀表現而言，呈現台東（南部）族群大於桃園、花蓮（北部）大於北部族群。籽粒乾重之表現在秋作方面為屏東族群最重，台中族群次之，較輕者為花蓮、桃園族群；而在果穗性狀方面各族群間有差異存在，但沒有趨勢可循。若以春秋二季之果穗乾重及籽粒乾重等產量性狀來做比較，呈現秋作大於春作之結果。上述結果顯示台南白玉米自日據時代引入台灣後已逾80年以上之歷史，種子一直由農民自行留種及傳播，因長期天然淘汰及農民有意或無意選種結果，顯示已有分化產生。 1999年秋作之6個不同地區之台南白族群進一步經集群及主成份分析的結果，可分成三個類群：類群Ⅰ為花蓮、桃園、雲林等3個族群；類群Ⅱ為屏東族群；類群Ⅲ為台東與台中族群。雲林、桃園2族群之遺傳距離最小為1.70，表示彼此關係較為密切。而2000年春作之6個不同地區之台南白族群，經分析的結果亦可分為三類群：類群Ⅰ為台中、雲林、台東等3個族群。類群Ⅱ為花蓮、屏東族群。類群Ⅲ為桃園族群。花蓮及屏東2族群遺傳距離最小為3.44，此2族群彼此關係亦較密切。 計算各族群一般化之外表型變異係數（GCPV）可知，各族群之遺傳歧異度有其差異性存在。在秋作環境中，台中族群之GCPV值最大（29.6），台東族群之GCPV值最小（24.0），可知，台中族群具最大之遺傳變異，台東族群之群內變異性最小。而在春作環境中，台中族群GCPV值仍為最大（32.1），最小者為花蓮族群（22.7）。在6族群中普遍以春作之GCPV值較大，故台南白玉米在育種改良上，春作時進行較易呈現豐富且多變異之遺傳基因組合。 在各族群內性狀間相關性的分析結果顯示，6個族群性狀間之相關程度不同。在試驗中可知，在不同族群、期作下，大多數族群在性狀間呈顯著正相關且表現一致者有株高與穗位高、葉面積；葉面積與穗位葉長及穗位葉寬；果穗乾重與籽粒乾重、穗長、百粒重、單行粒數；穗長與單行粒數；穗位高與葉數、葉面積；此表示這些性狀間之相關性並不受季節改變之影響，呈現相當穩定關係，可作為台南白族群改良時之參考。Abstract From the Tainan-White Population gathered from the diverse areas in Taiwan (Hualien, Taoyuan, Taichung, Yunlin, Pingtung, Taitung), planted in Taichung to exclude the environment factor, this study discovered significant difference of the averages of agronomic characters among the populations. With the vegetative characters, Taitung (south) population is greater than the northern ones located in Taoyuan and Hualien. In terms of the grain dry weight of autumn crops grains, Pingtung population is the heaviest, followed by Taichung population; the lighter ones include Hualien and Taoyuan. Meanwhile, differences in grain clusters do exist, but cannot be categorised in any manner. Comparing the ear dry weight and grain dry weight shows that the autumn crops is greater than that of spring. The results above indicate that, since Tainan-white maize was introduced to Taiwan during the Japanese occupation eighty years ago, the seeds being kept and planted by farmers, distinct diversion has occurred due to natural selection and farmers' intentional or unintentional choice. Further grouping and analysis of the main ingredients of Tainan-White population's 1999 autumn crops of six different areas can be divided into three clusters: The first cluster consists of Hualien, Taoyuan and Yunlin. The second cluster consists of Pingtung. The third cluster consists of comprises Taitung and Taichung. The minimum passing genetic distance of Yunlin and Taoyuan is 1.70, indicating closer relations. Analysis results of Tainan-White population's 2000 spring crops of six different areas can also be distinguished into three clusters: The first cluster included populations of Taichung, Yunlin and Taitung. The second cluster included populations of Hualien and Pingtung. The third cluster included populations of minimum generic passing distance of Hualien and Pingtung is 3.44, indicating closer relations between these two areas. Calculation of the generalized coefficient of phenotypic variation (GCPV) of the various populations reveals the genetic diversity among the various populationss. In the environment of autumn crops, Taichung population's GCPV is the greatest (29.6), while Taitung's is the smallest (24.0). From which, it is evident that Taichung population has the greatest genetic variations while Taitung's internal variations is the smallest. In the environment of spring crops, Taichung populations's GCPV remains the greatest (32.1); the smallest is Hualien (22.7). Among the six populations, the GCPV of spring crops are generally greater. Therefore, Tainan-white maize seed improvement shows richer and greater varied generic combinations in spring crops. Analysis of the correlations among the various populations characters different levels among the six groups. Experiment shows that of different populationss and planting period, the positive relations and consistent performance of most the populations are plant height, ear height and leaf area per plant, leaf area per plant and ear leaf length and ear leaf width; ear dry weight and grain dry weight, ear length, 100-kernel weight, kernel number; ear height and kernel number; ear height and total leaf number ,leaf area per plant. All of which indicate that the relations among these correlations of character are not affected by the change of seasons, and are rather stable, which can be of reference value in improving Tainan-White population.目 錄 頁次 中文摘要 1 一、緒言 3 二、前人研究 5 三、材料與方法 12 四、結果 (一)族群間及族群內農藝性狀之變異 17 (二)族群間遺傳距離之測量 32 (三)集群分析 35 (四)族群內之遺傳歧異度 35 (五)性狀間之相關關係 39 (六)主成份分析 65 五、討論 69 參考文獻 76 英文摘要 8