Studies on the DNA Sequence Variation of Sweet Potato (Ipomoea batatas (L.) Lam.)Varieties
Date Issued
2004
Date
2004
Author(s)
Chien, Ching-Hua
DOI
zh-TW
Abstract
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.
Subjects
粒線體 DNA
遺傳歧異性
甘藷
ISSR分子標誌
葉綠體 DNA
sweet potato
ISSR DNA marker
mtDNA
genetic diversity
cpDNA
Type
thesis