Geographically isolated populations of endemic orchids have evolved and adapted to an existence within specifi c ecological niches. These populations are highly susceptible to anthropogenic
infl uences on their microhabitats. The primary objective of conservation programs is the restoration of endangered populations to their ecologically sustainable levels, and the fi rst stage in the process of conservation involves estimation of molecular diversity at the level of the population. The approach described in this article involves the application of RAPD, Microsatellites and Chloroplast DNA markers for the characterization of the genetic structure of Paphiopedilum rothschildianum and Phalaenopsis gigantea, two endangered and endemic orchids of Sabah. This study has isolated a total of 96 microsatellite loci in P. rothschildianum and P. gigantea, 42 specifi c primer pairs have been designed for amplifi cation of microsatellite loci and are currently being applied to screen the breeding pools. The Chloroplast DNA regions amplifi ed by the primer pairs trnH-psbA and trnL-trnF exhibit distinct polymorphisms and can be used to establish phylogenetic
relationships. The ability of microsatellite loci to cross-amplify selected varieties of orchids has been determined. The molecular markers developed will be applied to estimate population diversity
levels and to formulate long-term management strategies for the conservation of endangered species of orchids of Sabah.
Chitinases are glycosyl hydrolases that cleave the β-1,4-glycosidic linkages between N-acetylglucosamine residues in chitin which is a major component of fungal cell wall. Plant chitinases hydrolyze fungal chitin to chitin oligosaccharides that serve as elicitors of plant defense system against fungal pathogens. However, plants synthesize many chitinase isozymes and some of them are not pathogenesis-related. In this study, three full-length cDNA sequences encoding a putative chitinase (EgChit3-1) and two chitinase-like proteins (EgChit1-1 and EgChit5-1) have been cloned from oil palm (Elaeis guineensis) by polymerase chain reaction (PCR). The abundance of these transcripts in the roots and leaves of oil palm seedlings treated with Ganoderma boninense (a fungal pathogen) or Trichoderma harzianum (an avirulent symbiont), and a combination of both fungi at 3, 6 and 12 weeks post infection were profiled by real time quantitative reverse-transcription (qRT)-PCR. Our findings showed that the gene expression of EgChit3-1 increased significantly in the roots of oil palm seedlings treated with either G. boninense or T. harzianum and a combination of both; whereas the gene expression of EgChit1-1 in the treated roots of oil palm seedlings was not significantly higher compared to those of the untreated oil palm roots. The gene expression of EgChit5-1 was only higher in the roots of oil palm seedlings treated with T. harzianum compared to those of the untreated oil palm roots. In addition, the gene expression of EgChit1-1 and EgChit3-1 showed a significantly higher gene expression in the leaf samples of oil palm seedlings treated with either G. boninense or T. harzianum.