Plastid evolution in a non-photosynthetic plant, Galeola lindleyana (Hook. F. & J. W. Thomson) Rchb. F. (Orchidaceae)

• Main Authors: I-Lun Tsai, 蔡依倫
• Other Authors: Sheng-Zehn Yang, Jer-Ming Hu
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/74406888890696785342

碩士 === 國立屏東科技大學 === 森林系 === 93 === The majority of green plants are autotrophic, in which they have the ability to obtain energy through indigenous photosynthesis. However, there are many groups of land plants are achlorophyllous and heterotropic (i.e. non-photosynthetic). We would like to examine the presence of plastid genome in one of the non-photosynthetic plants, Galeola lindleyana, of Orchidaceae. My thesis is to use degenerate primers to amplify DNA fragments from plastids, and selected nuclear and mitochondrial genes from Galeola lindleyana as comparisons. Plastid 16S rDNA, psaB, and rbcL sequences from the fourteen screened gene regions were successfully amplified. The later two sequences are predicted to be pseudogenes since both of the open reading frames are interrupted by stop codon. The evolutionary rate test showed that plastid genes of Galeola lindleyana exhibit faster evolutionary rate compared to other plants, but the rates among nuclear genes show no difference in Galeola lindleyana and other plants. Phylogenetic analyses based on the obtained sequences were conducted and all showed that Galeola lindleyana is a member of Vanilloideae. Our data provide the proof of the presence of plastid genome, and show the photosynthesis related genes are likely lost in Galeola lindleyana, which suggests there are other functions exist in order to maintain plastid genome.