History and perspectives of induction technology for agarwood production from cultivated Aquilaria in Asia: a review

Agarwood, the resinous product of Aquilaria spp.(Thymelaeaceae), is highly valued for medicinal and fragrant purposes. Unsustainable forest harvesting contributes to the declining population in the wild, threatening their existence. As a protection effort, cultivation occurred in range countries, mainly in Asia, effectively establishing mass plantations. The success of domesticating Aquilaria relies heavily on technological advancement in agarwood induction, without which the entire thriving industry will collapse. In this paper, we describe efforts since 1929 and current progress and variation in induction as practiced in Asia. The methods include traditional practices and artificial induction via inoculum and chemical inducer, experimented and patented or otherwise. Artificial induction methods are being developed to intensify agarwood production in terms of yield and quality. While traditional methods are commonly applied by rural planters, artificial methods with the use of specific agents/chemicals are seen as more appealing for inducing agarwood, and have a higher demand from entrepreneurs and plantation owners.Several issues related to induction technology faced by stakeholders in agarwood cultivation are presented, such as safety levels, cost, yields, and quality. We conclude by highlighting remaining challenges in induction methods and their associated technologies.

Molecular phylogenetic analyses based on the complete plastid genomes and nuclear sequences reveal Daphne(Thymelaeaceae)to be non-monophyletic as current circumscription

The diverse members of the genus Daphne are prized for their fragrant flowers.Despite being promising ornamental plants in many countries,genetic information of Daphne is scarce.In this study,the plastomes of four species and one variety of Daphne were sequenced and analyzed.The plastomes were typical and contained a pair of inverted repeat(IR)regions that separated the large single-copy(LSC)region from the small single-copy(SSC)region.With a length ranging from 132,869 bp(D.genkwa)to 174,773 bp(D.championii),106 to 141 genes were predicted.Comparative plastome analysis of the newly sequenced plastomes with four publicly available Daphne plastomes identified an expansion of the IRs,sequence variations,and mutational hotspots.Phylogenetic analyses indicated that the genus Daphne in its current circumscription is polyphyletic.Daphne genkwa was nested within the genus Wikstroemia,while D.championii was well resolved as sister to Edgeworthia.These findings concurred with results from our study that used nuclear ribosomal internal transcribed spacer sequence data.The conflicts on the molecular placement of D.championii and D.genkwa and the present taxonomic classification in Daphne suggest that a new intergeneric classification system of Daphneae warrants consideration.