Nucleotide variation in the GapC region of four species of Shorea and their putative hybrids

Abstract

Very little is known about the levels and patterns of DNA polymorphism in populations of tropical trees. In this study, we investigated population genetic structure of the four following Shorea species: Shorea acuminata, S. curtisii, S. leprosula and S. parvifolia from peninsular Malaysia using DNA sequences of Glyceraldehyde-3-phosphate dehydrogenase nuclear gene (GapC). The average nucleotide diversities of the investigated species for silent sites ( sil = 0.0027) were lower than those reported for herbaceous plants, and similar or somewhat lower than those of other woody species. These low levels of nucleotide diversities may be caused by small effective population size of Shorea species. We found that some individuals harbored atypical haplotypes consisting of sequences from two different species. The segmented architecture of these haplotypes suggests past inter-specific gene exchange and fertility of the hybrids. As demonstrated in this study analysis of DNA sequences provides genetic evidence for the occurrence of inter-specific hybridization and gives important insights into its evolutionary effects.

Development of SCAR Markers for Species Identification in the Genus Shorea (Dipterocarpaceae)

“…Hybridization among Shorea species has been reported in previous studies (ASHTON, 1982;HARADA et al, 1994;ISHIYAMA et al, 2003;ISHIYAMA et al, 2008). Based on sequences of the nuclear GapC and PgiC genes ISHIYAMA et al (2003ISHIYAMA et al ( , 2008 found similar or identical haplotypes and proposed the occurence of inter-specific hybridization between four Shorea species: S. acuminata, S. curtisii, S. leprosula and S. parvifolia.…”

“…Based on sequences of the nuclear GapC and PgiC genes ISHIYAMA et al (2003ISHIYAMA et al ( , 2008 found similar or identical haplotypes and proposed the occurence of inter-specific hybridization between four Shorea species: S. acuminata, S. curtisii, S. leprosula and S. parvifolia. In contrary, CAO et al (2006) found strong frequency differences in AFLP bands between species and a clear separation of S. leprosula and S. parvifolia based on the AFLP markers.…”

“…SCAR markers are generally used for different identification purposes in sample sizes of less than 100 (BRADEEN and SIMON, 1998;NEGI et al, 2000;SANTOS and SIMON, 2002;HUARACHA et al, 2004). More often, markers for species identification are tested in only a few samples per species (BEISMANN et al, 1997;ISHIYAMA et al, 2003;KRESS et al, 2005;ZIEGENHAGEN et al, 2005). Testing in large samples is difficult to carry out because the most frequently used molecular technique to differentiate among species is sequencing, i.e based on sequence differences in target regions.…”

Estimating the genetic variation in tropical tree populations: heterozygosity or allele number ?

“…Some of these studies are reported at this workshop by researchers at Kyushu University (Dayananda et al, 2003;Ishiyama et al, 2003;Sirikantamaras et al, 2003).…”

Wood production, wood technology, and biotechnological impacts

“…However, sequencing of the nuclear PgiC (phosphoglucose isomerase) gene in Shorea revealed that species belonging to each of the three timber groups balau, yellow meranti, and red meranti formed one specific (monophyletic) clade within Shorea (Kamiya et al 2005). Additional information on variation in nuclear gene markers is available for genus Shorea for the GapC (glyceraldehyde-3-phosphate dehydrogenase) region (Ishiyama et al 2004) and the ITS regions (K.S. Yulita & R.J. Bayer, unpublished; see Chapter 9 for a general explanation of the ITS regions).…”