利用Inter Simple Sequence Repeat (ISSR)探討台灣天竺草之遺傳變異

Genetic Diversity of Panicum maximum Determined by ISSR DNA Markers in Taiwan

陳美如(Mei-Ru Chen) ； 侯金日(Chin-Jin Hou) ； 林正斌(Jeng-Bin Lin) ； 侯新龍(Shin-Lon Ho)

《台灣農學會報》 11卷4期 (2010/08) Pp. 356-373

https://doi.org/10.6730/JAAT.201008_11(4).0004

摘要

天竺草(Panicum maximum)原產於熱帶及亞熱帶的非洲及印度，為多年生牧草，台灣於1908年由菲律賓引進試種且生育好，經過近百年的演化，天竺草已有許多變種產生。本研究收集台灣21縣市之天竺草樣本41個及綠天竺草樣本74個共115個收集系，以ISSR分子標誌探討此二草種之遺傳變異及地理分佈情形。由ISSR之結果獲得10個具有多型性及再現性良好的引子，在綠天竺草方面可擴增出54條條帶，其中有46條具有多型性DNA條帶，多型性比例佔83.7%，遺傳分化指數(Gst)為0.5517，基因流(Nm)為0.4063，遺傳距離矩陣介於0.0535-0.3574間。以遺傳相似度0.15為截點可分為5群，第一群包含台北和桃園地區；第二群包含新竹、苗栗、台中及彰化地區；第三群包含台南、屏東、台東、花蓮及宜蘭地區；第四群包含雲林和嘉義地區；第五群為高雄地區。在天竺草的ISSR分析中，共可擴增出49條條帶，其中36條具有多型性DNA條帶，多型性比例佔68.5%，遺傳分化指數為0.5779，基因流為0.3652，遺傳距離矩陣介於0.0188-0.3055間；以遺傳相似度0.11為截點可分為4群，第一群包含台中、南投及雲林地區；第二群包含嘉義、台南及高雄地區；第三群為屏東地區；第四群包含台東和花蓮地區。遺傳距離與地理距離之平均係數在綠天竺草和天竺草族群之相關係數分別為r=0.2228 (p=0.0209)和r=0.3825 (p=0.0118)，呈顯著的相關性，顯示二草種之分化均符合距離隔離模式。

關鍵字

天竺草 ； 簡單重複序列間之DNA片段 ； 群叢分析

並列摘要

Guineagrass (Panicum maximum) is a perennial forage grass which is original from tropical Africa and subtropical India. Guineagrass was introduced from the Philippines in 1908 and grew well in Taiwan. Over the past one hundred years, many various ecotypes have been observed. In this study, we have collected 115 lines, containing 41 lines of guineagrass and 74 lines of green guineagrass from 21 counties in Taiwan to determine the genetic variation and the geographical distribution of these two species by Inter Simple Sequence Repeat (ISSR) molecular markers. According to ISSR analysis, 10 UBC primers were positive. In green panicgrass, 54 bands were amplified and 46 bands were polymorphism. The percentage of polymorphism was 83.7%. The values of genetic differentiation (Gst) was 0.5517 and the gene flow (Nm) was 0.4063. The genetic distance matrix range was from 0.0535 to 0.3574. Green panicgrass could be divided into five groups based on the genetic similarity with 0.15 as the critical point. It included the 1st group with Taipei and Taoyuan, the 2nd with Hsinchu, Miaoli, Taichung and Changhua, the 3rd with Tainan, Pingtung, Taitung, Hualine and Yunlin, the 4th with Yilan and Chiayi and the 5th Kaohsiung, respectively. For guineagrass, 49 bands were generated and 36 bands were polymorphic typing. The percentage of polymorphism was 68.5%. The values of genetic differentiation (Gst) was 0.5779 and the gene flow (Nm) was 0.3652. The genetic distance matrix located between 0.0188 and 0.3055. Guinegrass could be divided into 4 groups based on the genetic similarity with 0.11 as the critical point. It included the 1st group included Taichung, Nantou and Yunlin, the 2nd with Chiayi, Tainan and Kaohsiung, the 3rd with Pingtung, the 4th with Taitung and Hualien, respectively. The values of genetic distance and geographic distance for these two species were r=0.2228 (p=0.0209) and r=0.3825 (p=0.0118), respectively. These results revealed that both guineagrass and green guineagrass showed a significant relationship between each other and met the requirement of the model for distant isolation.

並列關鍵字

Panicum maximum ； ISSR ； Cluster analysis