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Transferability of SSR markers from lychee (Litchi chinensis Sonn.) to pulasan (Nephelium ramboutan-ake L.). Abstract-Introduction. Pulasan and lychee are from the same family and closely related, therefore the SSR markers are expected to be highly transferable between these two taxa. We investigated the transferability of 12 lychee (Litchi chinensis Sonn.) simple sequence repeat (SSR) loci to pulasan (Nephelium ramboutan-ake L.). Materials and methods. Genomic DNA was extracted from 20 accessions of pulasan for the PCR amplification of the SSR loci using 12 pairs of SSR primers derived from lychee. The PCR products were resolved on denaturing polyacrylamide gels. Results. The percentage of SSR transferability from lychee to pulasan was 58.3% and the percentage of polymorphic SSR markers was 25%. Discussion. The moderate transferability and low polymorphism rates suggest the possibility of interruptions within the repeat motif and mutations in the flanking sequences of SSR repeat motifs. Our results did not reveal a high rate of transferability between lychee and pulasan. However, this study showed that the SSR markers developed in lychee are a good source of molecular markers for pulasan. Malaysia / Litchi chinensis / Nephelium ramboutan-ake / molecular biology / genetic markers / PCR / genetic polymorphism Transférabilité de marqueurs SSR du litchi (Litchi chinensis Sonn.) au kapulasan (Nephelium ramboutan-ake L.). Résumé-Introduction. Kapulasans et litchis sont de la même famille et étroitement liés, on s'attendrait donc à ce que les marqueurs SSR soient fortement transmissibles entre ces deux taxa. Nous avons testé la transférabilité de 12 marqueurs SSR du litchi (L. chinensis Sonn.) au kapulasan (N. ramboutan-ake L.). Matériel et méthodes. De l'ADN génomique a été extrait de 20 accessions de kapulasan afin d'amplifier des loci SSR en utilisant 12 paires d'amorces issues de litchi. Les produits issus de PCR ont été révélés sur gels de polyacrylamide. Résultats. Le pourcentage de la transférabilité des marqueurs SSR du litchi au kapulasan a été de 58,3 % et le pourcentage de marqueurs SSR polymorphes a été de 25 %. Discussion. La transférabilité modérée et les faibles taux de polymorphisme obtenus suggèrent que des interruptions aient pu intervenir dans le processus de répétition des séquences et que des mutations aient pu avoir lieu dans les séquences de motifs répétés des SSR. Nos résultats n'ont pas révélé un taux élevé de transférabilité entre le litchi et le kapulasan. Cependant, notre étude a prouvé que les marqueurs SSR développés pour le litchi sont une bonne source de marqueurs moléculaires pour le kapulasan. Malaisie / Litchi chinensis / Nephelium ramboutan-ake / biologie moléculaire / marqueur génétique / PCR / polymorphisme génétique

The majority of plant expressed sequence tags (ESTs) available in the public databases are from nonwoody species such as Arabidopsis, maize, soybean, and rice, with the exception of the model tree species, Populus. In this study, we report the first EST database constructed from the commercially important tree species Acacia. ESTs were generated from pooled RNA extracted from the mature, intermediate, and young inner bark tissues of an Acacia auriculiformis x Acacia mangium hybrid. Finally, 3,182 high-quality ESTs were analyzed representing a total of 1,982 unique transcripts (663 contigs and 1,319 singletons) for the inner bark cDNA library. A total of 1,053 unigenes (1,750 ESTs) showed similarities with protein sequences in public database where 867 were significant matches (E value≤e −10 ). Further analysis performed on unigenes with significant matches and known functions identified 231 genes including genes involved in cellulose, lignin, and hemicellulose biosynthesis. For cDNA library validation, quantitative real-time RT-PCR was performed to study the expression levels of the cellulose and lignin genes identified from this EST database in the phloem tissue of A. mangium, A. auriculiformis, and A. auriculiformis x A. mangium hybrid. All the seven candidate genes were expressed in all the individuals studied confirming the dependability of the EST database. The cDNA library and the EST database constructed are valuable resources for forest tree research aiming towards understanding the genetic control of wood formation and in the future endeavors to modify wood and fiber profile through marker-assisted breeding programs.

ABSTRACT. This study was directed at the understanding of the function of CCoAOMT isolated from Acacia auriculiformis x Acacia mangium. Full length cDNA of the Acacia hybrid CCoAOMT (AhCCoAOMT) was 1024-bp long, containing 750-bp coding regions, with one major open reading frame of 249 amino acids. On the other hand, full length genomic sequence of the CCoAOMT (AhgflCCoAOMT) was 2548 bp long, containing three introns and four exons with a 5' untranslated region (5'UTR) of 391 bp in length. The 5'UTR of the characterized CCoAOMT gene contains various regulatory elements. Southern analysis revealed that the Acacia hybrid has more than three copies of the CCoAOMT gene. Real-time PCR showed that this gene was expressed in root, inner bark, leaf, flower and seed pod of the Acacia hybrid. Downregulation of the homologous CCoAOMT gene in tobacco by antisense (AS) and intron-containing hairpin (IHP) constructs containing partial AhCCoAOMT led to reduction in lignin content. Expression of the CCoAOMT in AS line (pART-HAS78-03) and IHP line (pART-HIHP78-06) was reduced respectively by 37 and 75% compared to the control, resulting in a decrease in the estimated lignin content by 24 and 56%, respectively. AhCCoAOMT was found to have altered not only S and G units but also total lignin content, which is of economic value to the pulp industry. Subsequent polymorphism analysis of this gene across eight different genetic backgrounds each of A. mangium and A. auriculiformis revealed 47 single nucleotide polymorphisms (SNPs) in A. auriculiformis CCoAOMT and 30 SNPs in A. mangium CCoAOMT.

A new species Leptogomphus tioman is described based on male specimens collected from Tioman Island, Peninsular Malaysia. It is close to Leptogomphus risi Laidlaw in thoracic markings but is readily distinguished by its anal appendages and accessory genitalia.