| Summary: | 碩士 === 國立嘉義大學 === 農學研究所 === 95 === In this study, the genetic diversity of 74 green panicgrass (Panicum maximum var. trichoglume) and 41 guineagrass (Panicum maximum) in Taiwan was discussed by using the agronomic characters, inter simple sequence repeat (ISSR), and random amplified polymorphic DNA (RAPD). Results were summarized as follow:
1. Based on the 12 agronomic characters to examine 14 test regions in which containing 74 green panicgrass, the genetic distance was located from 4.3 to 26.5. They can be divided into 5 groups based on the Euclidean distances 13 as the critical point. The first group included Taipei, Taichung, Taitung, Tainan and Hualine, the second group included Taoyuan, Chiayi, Hsinchu, and Miaoli, the third included Changhua, Kaohsiung, and Yunlin, the fourth and fifth groups included Yilan and Pingtung, respectively. In the 9 test regions that included 41 guineagrass, the genetic distance was located from 10.5 to 74.7. It can be divided into 4 groups based on the Euclidean distances 29 as the critical point. The first group included Taichung, Chiayi, Yunlin and Tainan, the second group included Kaohsiung and Taitung, the third group included Pingtung and Hualien, the fourth group included Nantou.
2. According to the ISSR analysis, 10 out of 100 UBC primers were positive. In green panicgrass, total of 54 bands were amplified, and there were 46 bands to possess the polymorphic typing, the percentage of polymorphic is 83.7％. The values of genetic differentiation (Gst) is 0.5517, the gene flow (Nm) is 0.4063, and the genetic diatance matrix was located from 0.0535 to 0.3574. They can be divided into 5 groups based on the genetic similarity of 0.15 as the critical point. The first group included Taipei and Taoyuan, the second group included Hsinchu, Miaoli, Taichung and Changhua, the third group included Tainan, Pingtung, Taitung, Hualine and Yunlin, the fourth group included Yilan and Chiayi, and the fifth group included Kaohsiung. For about guineagrass, total of 49 bands were generated, and there were 36 bands to have revealed the polymorphic typing, the percentage of polymorphic is 68.5％. The values of genetic differentiation (Gst) is 0.5779, the gene flow (Nm) is 0.3652, and the genetic diatance matrix was located from 0.0188 to 0.3055. They can be divided into 4 groups based on the genetic similarity of 0.11 as the critical point. The first group included Taichung, Nantou and Yunlin, the second group included Chiayi, Tainan and Kaohsiung, the third group included Pingtung, the fourth group included Taitung and Hualien. On this two species, the values of genetic distance and geographic distance is r=0.2228 (p=0.0209*) and r=0.3825 (p=0.0118*), respectively. These results revealed that they showing the significantly relationship with each other, and agreement with the model of distant isolation.
3. According to the RAPD analysis, 18 out of 40 random primers were positive. In green panicgrass, total of 117 bands were amplified, and there were 89 bands to possess the polymorphic typing, the percentage of polymorphic is 73.2％. The values of genetic differentiation (Gst) is 0.4625, the gene flow (Nm) is 0.5811, the genetic diatance matrix was located from 0.0302 to 0.2205. They can be divided into 4 groups based on the genetic similarity of 0.10 as the critical point. The first group included Taipei and Taoyuan, Hsinchu, Miaoli, Taichung and Changhua, the second group included Yunlin, Chiayi and Tainan, the third group included Taitung, Hualine and Yilan, and fourth group included Kaohsiung and Pingtung. For about guineagrass, total of 105 bands were amplified, and there were 72 bands to possess the polymorphic typing, the percentage of polymorphic is 66.5％. The values of genetic differentiation (Gst) is 0.5229, the gene flow (Nm) is 0.4563, the genetic diatance matrix was located from 0.0401 to 0.2342. They can be divided into 4 groups based on the genetic similarity of 0.11 as the critical point. The first group included Taichung, Yunlin, Nantou and Chiayi, the second group included Tainan and Kaohsiung, the third group included Pingtung, the fourth group included Taitung and Hualien. On this two species, the values of genetic distance and geographic distance is r=0.5230 (p=0.0000*) and r=0.6912 (p=0.0000*), respectively. These results revealed that they showing the significantly relationship with each other, and agreement with the model of distant isolation.
4. In this test, we have collected the green ganicgrass and guineagrass from differentially 14 and 9 locations, respectively. According to the results from the studies of agronomic characters, ISSR, and RAPD analysis, indicating that the results from the agronomic characters analysis were influenced by those environmental factors. Therefore, the species involved in one group is selected according to the nearly geographical distance by the results of ISSR and RAPD analysis. Moreover, there are more accuracy and sensitivity of the results from the ISSR than RAPD analysis.
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