甘藷品種DNA序列變異之探討

Studies on the DNA Sequence Variation of Sweet Potato (Ipomoea batatas (L.) Lam.)Varieties

簡靖華(Ching-Hua Chien)

指導教授 ： 林順福

國立臺灣大學/生物資源暨農學院/農藝學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.01439

摘要

甘藷對環境適應能力強，又具有廣泛用途，為台灣重要雜糧作物之ㄧ。由於外表性狀不易區分大量甘藷品種及評估種原之遺傳歧異性，因此本研究由分子層次進行探討。本研究共篩選100條ISSR引子，共獲得81個具多型性之分子標誌，其中23個分子標誌具有較強之條帶，可利用於建立台灣地區甘藷品種之DNA指紋資料庫。甘藷品種之遺傳相似性分析結果顯示台灣主要甘藷品種間之遺傳距離介於12.5 % 到94.4 % 之間，各品種間之平均遺傳距離為54.9 %，顯示台灣收集之主要甘藷品種已具有較大程度的遺傳歧異性，由主成份分群分析顯示台灣育成甘藷品種與來自中國大陸種原仍具有很大的遺傳距離。為探討無性繁殖可能產生之遺傳變異，分別以兩個塊根用（台農66號及桃園1號）及兩個葉菜用甘藷品種（桃園2號及台農71號）為材料，分析相同品種不同植株之ISSR分子標誌之差異，各個參試品種調查約2,640~3,510個分子標誌，發現品種內約有0.94％∼1.86％之ISSR分子標誌變異。另外由16對葉綠體引子中選出四對葉綠體引子，得到七個多型性分子標誌供建立指紋資料及品種之遺傳歧異性分析，經比對品種來源與分群結果，確定其具有追蹤母本來源之效果；13對粒線體引子並未產生品種間長度多型性分子標誌，由nad7/1-2 (M5)引子對之產物經定序分析，結果顯示在840 bp序列中有個單一核苷酸變換位置(A或T)，依據此一變異可將參試品種分為兩大群，其中T群主要包含早期由日本、中國大陸引進之品種、台灣地區在來品種以及少部分台灣早期育成之品種，而A群則大部分為台灣新育成之品種。由於葉菜用甘藷品種台農71號以及桃園2號皆具有相同之三種分子標誌指紋，表示其可能來自相同之營養繁殖系。本研究所建立甘藷品種之核內及細胞質DNA分子指紋資料將可供甘藷品種鑑定、品種繁殖及品種改良之參考。

關鍵字

粒線體 DNA ； 遺傳歧異性 ； 甘藷 ； ISSR分子標誌 ； 葉綠體 DNA

並列摘要

Sweet potato is one of the most important crops in Taiwan due to its broad utilization and excellent adaptation ability to the environment. Because the number of phenotypic markers were not enough to identify a number of varieties, and to evaluate genetic diversity of sweet potato germplasm, the molecular markers were applied in this study. Eighty-one informative markers detecting difference among varieties were proposed after the screen of 100 primers. And 23 out of these markers with strong bands were used to analyze the genetic diversity among them. High genetic diversity among investigated varieties was found. Results of genetic similarity analysis revealed the genetic distance among varieties was range from 12.5 % to 94.4 %, and the averaged distance was 54.9 %. However, large genetic distance between varieties developed in Taiwan and introduced from China was observed both in cluster analysis and principal component coordinate analysis. In order to detect somatic variation resulted from vegetative propagation, individual plants from 2 varieties (TNG 66 and TAY 1) for tube production and 2 (TNG 71 and TAY 2) for leaf production were tested with ISSR markers. About 0.94 % ~1.86 % of ISSR DNA variation for each variety was detected from 2640~3510 surveyed markers. Four pairs of cpDNA primers producing polymorphic markers were selected from 16 pairs of universal primers. And 7 polymorphic markers amplified by these 4 primers were used to establish DNA fingerprints and to analyze genetic diversity among sweet potato varieties. The application of cpDNA markers in tracing female parents was verified. No polymorphic markers was found in testing 13 pairs of mtDNA primers. Nevertheless, one singal nucleotide difference (A/T) was found in an 840 bp fragment amplified by the nad7/1-2 (M5) primer pairs. The sequence difference could separate the sweet potato varieties developed in Taiwan from the others. From the results of ISSR DNA, cpDNA and mtDNA (M5) sequence analysis, two varieties (TNG 71 and TAY 2) for leaf production were probably derived from same clones. The nuclear and cytoplasmic DNA fingerprints developed in this study would provide information for variety identification, clonal propagation, and genetic improvement of sweet potato.

並列關鍵字

sweet potato ； ISSR DNA marker ； mtDNA ； genetic diversity ； cpDNA

參考文獻

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