Wichan Eiadthong

Phylogenetic relationships of Mangifera species revealed by ITS sequences of nuclear ribosomal DNA and a possibility of their hybrid origin

Abstract. The phylogenetic relationships among 14 Mangifera L. species of Thailand were analyzed by comparing sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA). Parsimony and neighbor joining (NJ) analyses revealed that the common mango (M. indica L.) was closely related to M. laurina Bl., M. sylvatica Roxb., and M. oblongifolia Hook. f. Mangifera foetida Lour. and M. odorata Griff. were also related to M. indica in both parsimonious and NJ trees, although these two species are classified into a different subgenus (subgenus Limus) from the subgenus Mangifera to which M. indica belongs. ITS sequence analysis revealed that several species have nucleotide additivity (two different nucleotides at the same locus) at several sites in the ITS region. Also, M. indica had several polymorphisms among cultivars. This finding may suggest a possibility of hybrid origin of Mangifera species, although Mangifera species are all assumed to be diploid having chromosome number of 2n=2x=40.

Rapid Whole Genome Amplification of DNA from Felids: Applications for Conservation Genetics

Abstract A major hindrance to conservation genetic studies of felids is the acquisition of DNA samples required for examining natural populations. In many cases research is complicated further by restrictions associated with the transport of biological materials from legally collected specimens. In this paper we assessed a method of rapidly amplifying whole genomes, both nuclear and mitochondrial, with the use of a strand displacement reaction (SDR) and the Phi29 DNA polymerase enzyme. We evaluated the SDR product with downstream amplification of microsatellite loci for genetic analyses of felids. The amplicon was of high molecular weight and provided a template equivalent to original DNA for polymerase chain reaction amplification of 10 microsatellites when properly stored samples were used. Genotypes of 6 felid species derived from genome amplifications scored identical to the original DNA, and we observed only 1 allelic dropout event among 67 heterozygotes. The Phi29 enzyme was able to amplify the genomes in samples up to 19 years old and those with degraded DNA. We extracted DNA and SDR amplified the genomes of 48 individuals of 5 felid species in Thailand in <3 days. We confirmed the SDR amplification of target DNA with 1 microsatellite for 47 of 48 samples (5 species).