- 學位論文
利用RAPD分子標記分析台灣咖啡族群遺傳歧異度與遺傳結構
Diversity and genetic structure among coffee populations in Taiwan revealed by RAPD molecular markers
摘要
本研究利用逢機增幅多型性DNA（Random Amplified Polymorphic DNA，簡稱RAPD）分子標記對台灣咖啡種原初步篩選、鑑定，以利快速獲得台灣Coffea arabica咖啡間遺傳歧異度與遺傳結構資料，試驗材料為2006年台灣咖啡節收集11個台灣咖啡族群樣品，總數為110個DNA混合樣品。在RAPD標記分析結果中，使用11個逢機引子，總共產生170個條帶，選取其中清晰且具多型性107個條帶，計算遺傳相似性介於67％至97％。再根據（Unweighted pair-group method with arithmetic average，簡稱UPGMA）進行群聚分析，繪製分群樹狀圖，此與（Principal Coordinate Analysis，簡稱PCoA）結果相似，雖曾多次國外引種，然而所有參試的遺傳相似度高達75％，只有南投縣與雲林縣歧異度略高，而與其他族群分開，此顯現台灣咖啡族群確實有再次由原生地引種，提高本地栽培種原歧異度的必要性。 實驗結果配合歷史文獻記載，推測可能是因為普遍選擇單一種苗，以致族群內歧異度偏低，而族群間種原關係相近，也造成部分族群併入別群，依據群聚分析結果，顯現台灣咖啡受環境阻隔影響，停留日據時代規模，使分化程度不明顯，無論以各別樣品或不同層級樣區的角度進行分析，台灣地區咖啡生豆遺傳歧異度偏低，對於大規模病害發生應戒慎恐懼。
並列摘要
The RAPD (Random Amplified Polymorphic DNA) markers were used to analyze the Taiwan coffee germplasm for understanding the genetic diversity and population structure. Eleven coffee accessions from the participant of the 2006 Taiwan Coffee Festival were used in this research. One hundred and ten blended DNA samples from the eleven coffee accessions were able to produce 170 unambiguous bands by 11 RAPD primers. One hundred and seven polymorphic bands were chosen for estimating the genetic diversity. The estimated genetic similarities between accessions were ranging from 67% to 97%. The cluster analysis based on the polymorphic bands using UPGMA methodology reveal similar result as the data analyzed by principle coordinate analysis. The average similarity between accessions was estimated to be 75% and not able to distinguished from one another other than the Nantou and Yunlin accessions. The result presented an evidence of narrow genetic diversity of the current coffee germplasm. Input of foreign germplasm should be required to broaden the genetic base of local germplasm. The records from local historical coffee introduction documentation provided an explanation to the great similarity estimated by this research. The similarity between the accessions could be due to the spreading the coffee germplasm during the Japanese occupation.