This thesis presents the systematics, epidermal defense, and bioprospecting of wild orchids. I mainly targeted Indonesian orchids, with particular emphasis on the genus Glomera with 169 species.... Show moreThis thesis presents the systematics, epidermal defense, and bioprospecting of wild orchids. I mainly targeted Indonesian orchids, with particular emphasis on the genus Glomera with 169 species. Four main challenges of this group of orchids were tackled. First of all, a web-based multilingual interactive key of Glomera, one of the lesser-known genera in the horticulturally popular necklace orchids, was constructed. This key simplifies species identification for further taxonomic revisions by both specialists and amateur orchid enthusiasts. Secondly, identification of non-flowering Glomera specimens in botanical gardens was sped up by producing DNA barcodes of herbarium preserved flowering type specimens. These DNA barcodes were matched with data obtained from vegetative fresh plants. Thirdly, improving protection of orchids in botanic gardens and nature reserves against herbivory was investigated. Centrifuge and feeding experiments showed that leaf trichomes and wax layers reduce both the adhesion and appetite of herbivorous snails. Lastly, bioprospecting was explored to help financing the maintenance of orchid collections in botanical gardens and protection of nature reserves. For this, traditional medicinal use was compiled from the literature and plotted on a molecular phylogeny. Potential clades with high antimicrobial potential were traced by employing two different methods: organ targeted and biological response based. The latter proved to be more effective. The research presented in this thesis provides new approaches to improve identification, protection against herbivory, and bioprospecting of wild orchids cultivated in botanical gardens and preserved in nature reserves. Show less
Bouman, R.W.; Kessler, P.J.A.; Welzen, P.C. van 2019
Two species of Phyllanthus collected and described by Koorders during his travels on the island of Sulawesi(Indonesia) are lectotypified, descriptions amended and their taxonomic affinity is... Show moreTwo species of Phyllanthus collected and described by Koorders during his travels on the island of Sulawesi(Indonesia) are lectotypified, descriptions amended and their taxonomic affinity is discussed. Phyllanthus mindorensis was found to be too similar to P. celebicus and is placed in the synonymy of the latter. A key is provided to the species of Phyllanthus on Sulawesi. Show less
Microbial biofilms causing elevated resistance to both most anti-microbial drugs and the host defense systems, which often results in persistent and difficult-to-treat infections. The discovery of... Show moreMicrobial biofilms causing elevated resistance to both most anti-microbial drugs and the host defense systems, which often results in persistent and difficult-to-treat infections. The discovery of anti-infective agents which are active against planktonic and biofilm microorganisms are therefore urgently required to deal with these biofilm-mediated infections. Plants are a rich source of new molecules with pharmacological properties for the development of new drugs. Indonesia is one of the countries which has a very diverse flora and a rich tradition in the use of medicinal plants. Since several Indonesian medicinal plants contain anti-microbial compounds it was considered conceivable that they might also be a source of new anti-biofilm compounds. The research present in this thesis has been focused on the screening and identification of Indonesian medicinal plant extracts and essential oils for their anti-microbial and anti-biofilm activity towards P. aeruginosa PAO1, Staphylococcus aureus Cowan I, and Candida albicans ATCC 10231. Preparative thin layer chromatography along with GC-MS and 1H-NMR elucidation were used to isolate and identify the active compound, and the result revealed that massoia lactone, the active compound of massoia oil, displayed potent activity against microbial biofilms in vitro and therefore has potential therapeutic implication for biofilm-associated microbial infections. Show less
