We have exploited the repetitive and dispersed nature of many long terminal repeat (LTR)-retrotransposon families for characterizing genome constitutions and classifying cultivars of the genus Musa. Insertional polymorphisms of the elements were studied using seven published and two newly designed primers facing outwards from the LTRs and reverse transcriptase (RT) domain of the retrotransposon. The primers generated specific amplification patterns showing the universal applicability of this marker type. The Inter-Retrotransposon Amplified Polymorphism (IRAP) markers distinguished the A and B genomes of the banana species (Musa acuminata Colla and Musa balbisiana Colla) and between banana cultivars. The IRAP markers enabled phylogenetic analysis of 16 Malaysian banana cultivars and determination of the genome constitution of hybrid banana (AAB, ABB, AABB, and AAAB), and gave information aboutancestral genotypes of the hybrids. In addition, the IRAP detected new retrotransposon insertions into the genome of tissue culture regenerants. This PCR-based IRAP assay is amenable to large-scale throughput demands in screening breeding populations and is applicable for any crop.

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Pollen and seeds of 12 genera and 28 species belonging to Justicieae namely, Anisotes,

We report on the isolation and characterization of several genes responsive to wounding in the tropical endangered tree Aquilaria malaccensis. Wounding triggers the formation of a fragrant substance inside the tree stem. Deduced amino acid of the cloned sequences exhibited sequence similarities to their respective homologs: transcription factors of the WRKY gene family (AmWRKY) and β-1,3-glucanase (AmGLU). A homolog to phenylalanine ammonia-lyase (AmPAL) from previous work was also included. All cDNA sequences were of partial lengths. We studied their expression profiles in a wounding-stress experiment. Mechanical wounding induces AmWRKY in an early response to wounding (3 h), and elevates AmPAL and AmGLU expressions after 16 h. It is possible that AmWRKY mediates early wounding response while AmPAL mediates response to fungal infection by coinducing AmGLU. Their homologs in other plants are known to inhibit fungal growth. Our data provide the first insight into the mechanisms of wounding responses in Aquilaria.

Horseshoe crabs are said to be declining worldwide. However, there is still no published report on the status of horseshoe crabs in Malaysia. Thus, we report here eight informative microsatellite markers that were developed using the 5'-anchored ISSR-PCR enrichment procedure to diagnose the population genetic structure of the mangrove horseshoe crab, Carcinoscorpius rotundicauda from Peninsular Malaysia. This set of markers was tested on 127 samples and showed polymorphism in this species. Hence they should be useful in future essential population genetic studies of these living fossils in the Southeast Asian region.