Palynology study was undertaken on 32 taxon of Malaysian Dipterocarpaceae belonging to four genera Shorea, Hopea, Parashorea and Neobalanocarpus heimii, to investigate pollen morphology systematic significance at lower hierarchical levels. Results show that pollen morphology within these four groups is fairly uniform. There is no character that can really separate these four genera. However S. maxima can be distinguished from other Shorea by its crotonoid exine ornamentation and it could be a diagnostic character for this species. The colpate apertures and the closely comparable exine ornamentation confirm the homogeneity of this tribe. This is similar to the results reported by Erdtman (1952) and Maury et al. (1975). The presence of two types of pollen grain, tricolpate and tetracolpate, strongly suggests it corresponds to the species chromosome number or more specifically polyploidy. The results of this present study show that there are overlapping morphological characters in these two closely allied genera Hopea and Shorea. The pollen morphology in Hopea shows an agreement with Ashton’s classification (1982) at subspecies level. All species in Parashorea show similarities in pollen morphology with an exception in P. tomentella which is slightly different in exine ornamentation. This study has shown that pollen characters do not provide much information for systematic analysis especially at lower hierarchical levels except for genus Hopea.
Kajian kehadiran dan jenis trikom telah dijalankan ke atas lima spesies Neesia daripada famili Bombacaceae. Hasil menunjukkan bahawa kehadiran trikom jenis dendritik, berkelenjar, ringkas unisel, peltat sisik dan stelat dalam genus Neesia. Kehadiran trikom stelat boleh dijadikan ciri diagnosis spesies Neesia malayana, trikom peltat sisik bagi Neesia altissima dan trikom ringkas unisel bagi Neesia piluliflora. Trikom berkelenjar merupakan ciri sepunya dalam semua spesies yang dikaji. Sementara kehadiran trikom dendritik tidak mempunyai nilai taksonomi yang begitu signifikan tetapi masih boleh digunakan untuk membezakan spesies. Kesimpulannya hasil kajian ini menunjukkan bahawa kehadiran trikom pada lamina daun Neesia mempunyai nilai taksonomi terutamanya di peringkat spesies.
Comparative leaf anatomy study were conducted in three taxa of Acanthaceae from peninsular Malaysia. Three chosen taxa were Acanthus ebracreatus(Vahl), Andrographis paniculata (Burm.f.) Wall. exNees and Chroesthes longifolia(Wight) B. Hansen which is commonly used as traditional medicine especially in peninsular Malaysia. The main objective is to identify the leaf anatomical characteristics that can be used in plant identification and also for supportive data in plant classification. The procedures involved such as cross section using sliding microtome on the petiole, lamina, midribs and marginal, leaf clearing and observation under light microscope. Results have shown the similarities and variations in leaf anatomical characteristics. The anatomical characteristics observed include petiole and midrib outlines, patterns of petiole and midrib vascular bundles, presence of cystolith cells, presence of hypodermis layers in lamina and presence and types of trichomes. In conclusion, results showed that anatomical characteristics have taxonomic significance that can be used in classification especially at species level.
Acanthaceae merupakan famili tumbuhan berbunga di bawah order Lamiales dan terdiri daripada sekurang-kurangnya 4,000 spesies di kawasan tropika dan juga kawasan subtropika dengan genus Justicia merupakan genus terbesar. Kajian mikromorfologi petal dan sepal telah dijalankan ke atas ke atas enam spesies iaitu Justicia betonica L., J. carnea Lindl., J. comata (L.) Lam., J. gendarussa Burm.f., J. procumbens L. dan J. ptychostoma Nees. Kaedah kajian termasuklah penetapan bunga di dalam larutan penetap, siri dehidrasi, titik pengeringan genting dan cerapan di bawah mikroskop imbasan elektron. Hasil kajian menunjukkan kesemua enam spesies mempunyai variasi dan perbezaan mikromorfologi pada permukaan epidermis petal dan sepal. Kutikel lilin boleh ditemui pada kedua-dua permukaan epidermis petal dan sepal kesemua spesies yang dikaji. Kutikel lilin butir merupakan satu-satunya jenis kutikel lilin yang ditemui pada kesemua permukaan petal dan sepal spesies kajian. Terdapat lapan jenis trikom ditemui pada permukaan epidermis sepal dan juga lapan jenis trikom pada permukaan epidermis petal. Justicia betonica boleh dibezakan secara langsung dengan kehadiran stomata amfidiasitik pada permukaan epidermis petal dan stomata tidak hadir pada permukaan petal spesies yang lain. Kesimpulannya, hasil kajian ini membuktikan ciri mikromorfologi petal dan sepal mempunyai kesignifikan sistematik dan boleh digunakan sebagai data sokongan bagi pembezaan dan pengenalpastian spesies dalam genus Justicia.
The factors responsible for the low solubility percentage of oil palm empty fruit bunch (OPEFB) cellulose pulp compared
to kenaf when dissolved in aqueous NaOH/urea solvent system was reported. Physical and chemical properties of both
cellulose pulp were studied and compared in terms of the lignin content, viscosity average molecular weight (Mη),
crystallinity index (CrI), cellulose pulp structure and their zero span tensile strength. The structure of both OPEFB and
kenaf cellulose pulp were characterized using high powered microscope and field emission scanning electron microscopy
(FESEM) assisted by ImageJ® software. The results show that the most significant factor that affected the OPEFB and
kenaf cellulose dissolution in NaOH/-urea solvent was the Mη with OPEFB having a higher Mη of 1.68×105 compared to
5.53 × 104 for kenaf. Overall, kenaf cellulose appeared to be produced in higher quantities presumably due to its lower
molecular weight with superior tensile strength and permeability in comparison to OPEFB.