Source: SEAMEO BIOTROP's Research Grant | 2011
Abstract:The demand for agarwood or gaharu is high in the world market but full knowledge on its production mechanism from gaharu tree species like Aquilaria and Gyrinops is still under developed. Formation of gaharu is strongly suspected to be influenced by genetic factors and molecular interactions involving the host tree with fungi such as Fusarium and Acremonium. The declining natural populations due to intensive and extensive agarwood harvesting has made many species of Aquilaria and Gyrinops earned an endangered status from CITES, and international trading is banned unless it is certified as eco-friendly.
Molecular marker has been widely used as fingerprint to characterize a species or certain clone. It is also utilized in mapping of certain quantitative characters which has high economic value (QTL). A QTL map is a critical input to develop a marker-assisted selection process in a breeding program.
This research was able to develop microsatellite markers for Aquilaria malaccensis from its DNA isolated from leaf samples. These microsatellite markers were able to fingerprint tree accessions of A. malaccensis that are capable of producing agarwood from those that are not. However, further testing of these molecular markers requiring more tree samples are still needed for its effectiveness in differentiating the accessions.
The research also obtained the total RNA isolates from plantlets of two agarwood tree species, ie. A. malaccensis and A. microcarpa, that have been cultivated with the fungus Acremonium and have produced a fragrant gaharu oil droplets in vitro. Isolation of total RNA is the first step in contructing cDNA library that could be used to selectively amplify differentially expressed sequences needed to generate clones of genes that are expressed only in a certain stage of development of an organism.
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