| Summary: | 博士 === 國立中興大學 === 農藝學系所 === 100 === Abstract
Microsatellites, also named simple sequence repeat (SSR), is a 1-6 bp tandem repeat units which widely existed in eukaryote genomes. SSR markers had been applied in different research fields because of its abundant numbers in genome, codominant and easy for analyzed by PCR. It was known that time and cost consuming for isolating SSRs from new species, and EST sequences were available with economical species, which applications and numbers of SSR markers were limited in species with unknown genome information. However, SSR markers transferred from related species has been proven for expending SSR applications from species with known genome information into those with unknown genome information. In addition, the transferred SSR markers indicate the flanking sequences of source SSR markers were conserved in target genome. Monocot species with plenty of known genome information could be a rich source for transferring SSR into other plant species. In this study, we tested the ability of 120 monocot SSR markers transferred into three different collected plant populations. The transferability from monocot SSRs and the ability for genetic diversity analysis in individual population was estimated. First, monocot SSR markers transferred into 21 different bamboo species, with 68.3% transferability in cross-genera level. Besides, bamboo species could be classified into two types of rhizome, runner and clumper after genetic diversity analysis. Second, we tested the transferability of monocot SSR markers into 16 Pinales species, which indicated the 48.5% cross-orders transferability in Pinales. However, Pinales species could not be clustered as traditional taxonomy. In the last part, 67 species belonging to 29 orders were tested which included ferns, gymnosperms and angiosperms represent covered the plant kingdom. It was shown that 50.3% transferability from monocot into tested species indicated middle level of conservation of monocot SSR flanking sequences during the course of plant evolution. Besides, species could not be classified into ferns, gymnosperm and angiosperm as traditional taxonomy.
In concluded, monocot SSR markers had middle level of transferability to tested species, which indicated that flanking sequences of monocot SSR markers were widely conserved in tested genomes. Besides, the discrimination ability of transferred monocot SSR markers was useful in cross-genera level only. However, sequencing the amplified products from target genome for understanding whether source SSR sequences still contained in target genome will be needed in the future.
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