Notes on Discriminating Morphological Characters for Generic and Sectional Classification of Musaceae in Thailand

ABSTRACTMorphological characters have been used effectively in classification of the banana family, Musaceae. Most taxonomic features are qualitative characters which require experience in evaluation and are subjected to individual opinions. On the other hand, though not many, quantitative characters can be directly measured on sites or from photographs. The objective of this study was to evaluate efficiency of these quantitative features in the classification of the banana family in Thailand. A total of 16 quantitative morphological characters of 143 accessions from 10 native taxa and one introduced Musella species were assessed. All quantitative data were evaluated by box-plot analysis, principal component analysis and discriminant analysis. It was found that the quantitative data are useful in the classification at the generic level in Musaceae and at the sectional level of Musa. All three genera can be distinguished by pseudostem height, number of sucker plants and fruit pedicel length. At sectional level, number of fruit rows on mid hand can separate the sections Rhodoclamys and Callimusa from Musa and leaf blade length can differentiate Rhodoclamys from Callimusa. Interestingly, fruit pedicel length and fruit apex length which were used in Musa acuminata descriptors at subspecific level were not significantly different in this study.Keywords: Characterization, Morphometrics, Musaceae, Numerical Taxonomy, Phenetic analysi

A new species of Argyreia (Convolvulaceae) from Thailand

Argyreia pseudosolanum Traiperm & Suddee, sp. nov. from the NE region of Thailand is described and illustrated. The new species is remarkable in having a very distinctive corolla shape similar to Solanum, and staminal filament bases glabrous or nearly glabrous with a few multicellular, uniseriate hairs at the attachment point on the corolla tube. Detailed descriptions, illustrations, a summary of the ecology and an IUCN conservation status are provided

Revisiting the morphology, microstructure, and properties of cellulose fibre from pineapple leaf so as to expand its utilization

Pineapple leaf waste is an agricultural product that is available in large quantities and is still under-utilized. Therefore, the aim of this work was to investigate the morphology, microstructure, and mechanical properties of pineapple leaf fibre (PALF) such that its full potential may be realized. Pineapple leaf, its fibre bundles and elementary fibres have been investigated. Morphology, size, and mechanical properties of fibre bundles extracted from different parts (i.e. bottom, middle and top) of a leaf were studied. It was found that the PALF obtained from vascular tissue and from the mesophyll have different macroscopic shapes. Both, however, contain micron-size elementary fibres of similar size and shape. Size and properties of fibre bundles change from the bottom end of a leaf toward the top end. Pineapple leaf microfibre (PALMF) was found to be smaller in diameter than other natural fibres. It is also very long and its structure changes according to its position along the leaf. At the bottom end a clear and large central hole or lumen can be observed. At the top the lumen becomes almost undetectable. The mechanical strength of PALMF appears to decrease, albeit very slightly, toward the tip of the leaf. The mechanical properties of the fibres are relatively high and comparable to that of flax and hemp fibres which are widely studied and used as reinforcing materials in composites. Very long microfibre can easily be obtained from fibre bundles by dissolving the binding matrix. Potential applications for this microfibre are suggested

Compatibility systems and pollinator dependency in morning glory species (Convolvulaceae)

Abstract Background The Convolvulaceae is a large family containing species exhibiting a range of breeding systems and pollinated by diverse animal taxa. We studied the pollination ecology of 15 Convolvulaceae species, representing seven genera (Argyreia Lour., Camonea Raf., Evolvulus L., Hewittia Wight & Arn., Ipomoea L., Merremia Dennst. ex Endl., and Operculina Silva Manso), in northeastern Thailand, a family that is highly diverse yet understudied in the paleotropics. Specifically, we studied their compatibility systems and degrees of pollinator dependency using pollination experiments, examined pollinator composition and visitation rates using video observation, and determined if there is an association between pollinator visitation rates and degree of pollinator dependence. Results Our results showed that most species are self-compatible, but the degree of pollinator dependence varies. Six species were found to be highly dependent on pollinators, as two are self-incompatible and four are self-compatible but had reduced seed set when pollinators were excluded, possibly due to herkogamy. Seven species showed low dependence on pollinators and seed set remained high when pollinators were excluded. Pollinator dependence was inconclusive for two species as seed set was low in all pollination treatments. We also found an association between pollinator visitation rates and degree of pollinator dependence. Specifically, species exhibiting high pollinator dependence received frequent visits from pollinators, while species exhibiting low pollinator dependence either received frequent visits from pollinators (and received high amounts of xenogamous pollen) or infrequent visits from pollinators (and received significantly lower amounts of xenogamous pollen). Most of our study species were primarily visited by bees (e.g., Lasioglossum, Amegilla, Apis, and meliponines), with the exception of one night-blooming species that was visited primarily by crepuscular butterflies and hawkmoths. Conclusions The cumulative findings of this study demonstrate how pollinator dependence is influenced by breeding system, and suggest that pollinator visitation is consistently high for species exhibiting high pollinator dependence but varies across species exhibiting low pollinator dependence. Our findings are also important for assessing the conservation risks of paleotropical Convolvulaceae

Another New Thai Argyreia Species (Convolvulaceae).

A new species of Argyreia (Convolvulaceae) from Thailand is described and illustrated: A. albiflora. The morphological distinctions of this new species and its relationships with allied species are discussed. Micromorphological evidence is presented using scanning electron microscopy (SEM) and light microscopy (LM) demonstrating that microscopic features of the upper leaf surface are useful in separating species that are similar on a macromorphological level

Functional Ecology of External Secretory Structures in <i>Rivea ornata</i> (Roxb.) Choisy (Convolvulaceae)

Plants have evolved numerous secretory structures that fulfill diverse roles and shape their interactions with other organisms. Rivea ornata (Roxb.) Choisy (Convolvulaceae) is one species that possesses various external secretory organs hypothesized to be ecologically important. This study, therefore, aimed to investigate five secretory structures (nectary disc, petiolar nectaries, calycinal glands, staminal hairs, and foliar glands) using micromorphology, anatomy, histochemistry, and field observations of plant–animal interactions in order to assess the functional contributions of these structures. Results show that the nectary disc and petiolar nectaries are complex working units consisting of at least epidermis and ground tissue, while the other structures are glandular trichomes. Various groups of metabolites (lipids, phenolic compounds, polysaccharides, terpenoids, flavonoids, and alkaloids) were detected in all structures, while starch grains were only found in the nectary disc, petiolar nectaries, and their adjacent tissues. Integrating preliminary observation of animal visitors with micromorphological, anatomical, and histochemical results, two hypotheses are proposed: (I) nectary disc and staminal hairs are important for pollination as they potentially attract and reward floral visitors, and (II) petiolar nectaries, calycinal glands, and foliar glands contribute to plant defense. Specifically, petiolar nectaries and calycinal glands provide protection from herbivores via guard ants, while calycinal and foliar glands may use plant metabolites to help prevent tissue damage from dehydration and insolation

Floral micromorphology of the genus Ensete Bruce ex Horan. (Musaceae) in Thailand

To fulfil scarce and incomplete information on floral micromorphology of ensets (Ensete Bruce ex Horan.) in the banana family (Musaceae), a comparative anatomical study of two species: E. glaucum (Roxb.) Cheesman and E. superbum (Roxb.) Cheesman, native to Thailand was conducted. It was found that, apart from five fertile stamens presented in other members of the Musaceae family, both ensets possess a short staminode. It is suggested from this investigation that six is the basic number of Ensete androecial whorl and the taxa could secure the most primitive status within the family and the Zingiberales order, of which stamen numbers are reduced. The results also indicated that the vascular bundle position in compound tepal, the vascular patterns in vascular zone of ovary and cell shapes of stigma epidermis and the ovary cortex are of systematic significance in conjunction with pollen size and exine ornamentation. These useful micromorphological characters can be further applied for identification of other Ensete species distribute elsewhere in the world

Systematic importance of rhizome stelar anatomy in selected Monilophytes from Thailand

The present research aimed to investigate a possible relationship between rhizome stelar anatomy and current phylogenetic fern classifications. Forty-eight species of Thai ferns belonging to 46 genera in 25 families were collected from the field and their stelar anatomy was investigated using the paraffin method. Haplostele, actinostele, solenostele, dictyostele and arthrostele rhizome types were observed, but these anatomical features appear to be more closely correlated with the traditional morphological classifications, rather than recent molecular phylogenetic ones