Sri Lankan passion fruit mottle virus, a potyvirus infecting golden passion fruit in Sri Lanka

A sap-transmissible virus, provisionally named Sri Lankan passion fruit mottle virus (SLPFMV), was isolated from Passiflora edulis f. flavicarpa and shown to induce leaf mottling and distortion in that host. The virus infected 23 species in five plant families with systemic infection being common in the Passifloraceae. Chenopodium amaranticolor was a good local lesion host and Passiflora foetida was a useful systemic host for purification. In P. foetida extracts, SLPFMV lost infectivity after 10 min between 70–75°C, 6–7 days at 20–23°C and at dilutions of 10^--⁵ -W^-6. The virus had flexuous, filamentous particles with a normal length of c. 841 nm. Two polypeptides of mol. wt c. 33 200 and 28 700 were detected in purified virus preparations, and a major species of double-stranded RNA (mol. wt 7.0 × 10⁶), was detected in infected plants. Pinwheels, tubular and laminated inclusions were found in ultrathin sections of infected P. edulis f. plavicurpa and cylindrical inclusions were observed in epidermal strips. SLPFMV was transmitted by the aphids Myzus persicae, Aphis spiraecola, A. gossypü and A. cruccivora after brief acquisition feeds. SLPFMV reacted with antisera to several potyviruses including passion fruit woodiness virus, passion fruit ringspot virus, potato virus Y and watermelon mosaic virus 2 and thus, apparently, is a member of the potyvirus group.     

Pollen morphology of endemic species of the Horton Plains National Park,Sri Lanka

The pollen morphology of 27 endemic and palaeoecologically-important species belonging to 16 families and 20 genera from the mountain rain forests of Sri Lanka was studied using both light (LM) and scanning electron microscopy (SEM). The pollen grains exhibit a wide range of morphological characters. Their sizes (P and E) are in the range 10-53 2 9-60 mum, and they are distributed among seven shape classes. All the taxa have radially-symmetrical pollen grains except for Impatiens (bilateral). The amb varies from rounded to triangular, with intermediate shapes possible. The pollen grains of all the Lauraceae species studied are inaperturate and microspinose, with a thin, fragile, perforated exine. Sarcococca zeylanica (Buxaceae) has pantoporate pollen grains and a Croton -pattern consisting of faintly striate pegs of various shapes attached or enveloping the smooth rings. Colp(or)ate, syncolpate to parasyncolp(or)ate pollen grains with rugulate to perforate exine patterns occur in Eugenia mabaeoides ssp. mabaeoides and Syzygium ssp. (Myrtaceae). Osbeckia walkeri (Melastomataceae) has heterocolpate pollen with fossulate, foveolate to perforate exine pattern. 3-colporate, microreticulate pollen grains are met with in Euonymus revolutus (Celastraceae), and scabrate-microreticulate ones in Calophyllum walkeri (Clusiaceae). Hedyotis lawsoniae (Rubiaceae) pollen is microreticulate to perforate, while pollen of the Elaeocarpus (Elaeocarpaceae) species is 3-colporate, smooth to scabrate-perforate. Casearia thwaitesii (Flacourtiaceae) has 3-colporoidate pollen grains with a smooth, imperforate to occasionally sparsely perforate exine. Mastixia spp (Cornaceae) have a granular-perforate exine pattern, while Adinandra lasiopetala (Theaceae) has a smooth-perforate exine pattern. Triangular 3 (4)-colporate, and indistinctly faintly microreticulate-perforate pollen was found in Rhamnus arnottianus (Rhamnaceae), rugulate-perforate in Isonandra montana (Sapotaceae) and verrucate-perforate in Symplocos elegans (Symplocaceae). Glochidion coriaceum (Euphorbiaceae) has a 5-colporate grain with a coarsely reticulate exine pattern. Pollen grains of Impatiens walkeri and I. thwaitesii (Balsaminaceae) are bilateral, 4-colpate, reticulate and granular. A pollen key based on light microscope is constructed for all the taxa studied.     

Rostral horn evolution among agamid lizards of the genus Ceratophora endemic to Sri Lanka.

The first phylogenetic hypothesis for the Sri Lankan agamid lizard genus Ceratophora is presented based on 1670 aligned base positions (472 parsimony informative) of mitochondrial DNA sequences, representing coding regions for eight tRNAs, ND2, and portions of ND1 and COI. Phylogenetic analysis reveals multiple origins and possibly losses of rostral horns in the evolutionary history of Ceratophora. Our data suggest a middle Miocene origin of Ceratophora with the most recent branching of recognized species occurring at the Pliocene/Pleistocene boundary. Haplotype divergence suggests that an outgroup species, Lyriocephalus scutatus, dates at least to the Pliocene. These phylogenetic results provide a framework for comparative studies of the behavioral ecological importance of horn evolution in this group.     

Coat colour variation in the banded palm civet Hemigalus derbyanus and in Owston's civet Chrotogale owstoni

1. Coat colour variation was studied in two viverrid species belonging to the subfamily Hemigalinae, on the basis of museum specimens and observations of live animals. 2. In both species, polymorphism and ontogenetic colour change occur, and in the Owston's civet, sexual dimorphism in coat colour was identified.     

A new rhizomatous Oryza species (Poaceae) from Sri Lanka

VAUGHAN, D. A., 1990. A new rhizomatous Oryza species (Poaceae) from Sri Lanka. The confusing taxonomy of the Sri Lankan Oryza officinalis complex is clarified with the recognition of a new rhizomatous species, Oryza rhizomatis Vaughan. This species has been found across the dry zone. The other species of the complex in Sri Lanka, O. eichingeri , occurs in moist habitats and is smaller and less common than 0. rhizomatis. The new species is described.     

A review of the floral composition and distribution of mangroves in Sri Lanka

Recently published reports list numbers and distributions of Sri Lankan mangrove species that outnumber the actual species present in the field. The present study serves to review this literature and highlight the causes of such apparently large species numbers, while providing an objective and realistic review of the mangrove species actually present in Sri Lanka today. This study is based on standardized fieldwork over a 4-year period using well-established diagnostic identification keys. The study indicates that there are at present 20 identified 'mangrove species' (major and minor components) and at least 18 'mangrove associates' along the south-western coast of the island, and addresses the importance of clearly defining these terms. Incorrect identifications in the past have adversely affected interpretation of species composition in the framework of biogeography, remote sensing and biological conservation and management. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 29–43.     

Distribution of some triterpenes and phenolic compounds in the extractives of endemic dipterocarpaceae species of Sri Lanka

Extractives of bark and/or timber of 11 species belonging to the genera Cotylelobium, Hopea, Shorea, Vateria and Vatica yielded a fatty-acid ester, a sitosteryl ester, β-amyrin acetate, β-amyrin, dipterocarpol, ursolic acetate, lupeol, sitosterol, ursolic acid, betulinic acid, hexamethyl-coruleoellagic acid, tetramethylellagic acid, chrysophanol and scopoletin. The distribution of these compounds in 18 other species was examined by TLC screening.     

The seasonality of monsoonal primary productivity in Sri Lanka

The relationship between phytoplankton primary production and seasonality of physico-chemical parameters were examined for five man-made lakes in the dry-zone of Sri Lanka. Sri Lanka experiences two monsoons dividing the year into four meteorological seasons: — the North East (October–December) and South West (April–June) monsoons and the two inter-monsoons. A significant log linear relationship was found between Secchi disc depth and the depth of the euphotic zone which was lowest during the NE monsoon. Maximum mean photosynthetic rate ranged from 0.935 ± 0.067 SE to 0.479 mg O₂l^–1 h^–1 ± 0.115. Gross primary productivity which ranged from 0.378 g O₂ m^–2 h^–1 in the NE monsoon to 0.980 g O₂ m^–2 h^–1 in the SW monsoon showed significant season variation. This is shown to be determined either directly or indirectly by the light regime.     

Low genetic diversity in the masked palm civet Paguma larvata (Viverridae)

The masked palm civet is distributed through south-east Asia, China and the Himalayas. Because of its potential role in the severe acute respiratory syndrome (SARS) epidemic, it has become important to gather information on this species, and notably to provide a tool to determine the origin of farm and market animals. For this purpose, we studied the genetic variability and the phylogeographic pattern of the masked palm civet Paguma larvata . First, two portions of mitochondrial genes, cytochrome b and the control region, were sequenced for a total of 76 individuals sampled from China, the Indochinese region and the Sundaic region. Results indicated a low genetic variability and suggested a lack of a phylogeographic structure in this species, which do not allow inferring the geographic origin of samples of unknown origin, although it is possible to distinguish individuals from China and the Sundaic region. This low variation is in contrast to the well-marked morphological differentiation between the populations in the Sundaic and Chinese–Indochinese regions. We also used five microsatellite loci to genotype 149 samples from two wild and four farmed populations in China, where the masked palm civet is farmed and where the SARS coronavirus was isolated. These analyses also showed a reduced variability in Chinese civets and showed that farmed populations did not exhibit a lower genetic diversity than wild populations, suggesting frequent introductions of wild individuals into farms.     

Ranging behavior of the Asian elephant in Sri Lanka

We studied the ranging patterns of 10 elephants in and around the Yala protected area complex, southern Sri Lanka, using VHF radio telemetry. All tracked elephants displayed similar ranging patterns. The observed home ranges were small (mean=115.2±64.0 km²) relative to reported home ranges in India, possibly in response to high habitat productivity and abundant perennial water sources. Elephants showed high fidelity to their ranges. Home ranges had relatively large core areas, suggesting intensive use of habitat. No geographically distinct seasonal ranges or migratory behavior was observed. Home range overlap was high, and territoriality was absent. Male musth ranges were considerably larger than non-musth ranges and may signify mate searching. Most elephants ranged both in and outside protected areas, suggesting that resources outside protected areas were important for their survival. Thus, translocating and restricting elephants to protected areas will be detrimental to their survival, as it limits resource access. The ranging patterns of Asian elephants suggest that conservation of the species requires their management both in and outside protected areas.     

The taxonomy and biogeography of the Cladocera

For a variety of reasons, including the analysis of a number of taxa having the same names on different continents, we have concluded overwhelmingly that the chydorid Cladocera are not cosmopolitan in distribution but instead are restricted to smaller regions by their specific ecological requirements for habitat type and also by long-term events in earth history. Recent study ofChydorus faviformis and species resembling it indicates there has been no effective exchange of genetic material between North America and South America, nor between Australia and Asia, nor even between China, Malaysia, and India in southern Asia. Moreover, the patterns of distribution are even narrower than this, as in North America, for example, taxa having the same names in the southern states as in the northern states are differentiated at the species level in some instances, possibly in most. Southern species push northward along the Atlantic Coast for varying distances, one species having reached Nova Scotia and Newfoundland probably during the warm interval in mid-Postglacial time. Thus, when species are studied closely to define their morphological limits, cosmopolitanism disappears, and patterns of distribution emerge that are very similar to those of other animals and plants. The ‘species’ that have been claimed to be cosmopolitan are being shown to be groups or complexes of morphologically similar species instead, each member species of which has a much more restricted distribution than the group or complex as a whole. To explain how the different continents can have such similar lists of ‘species’ without intercontinental dispersal of resting eggs occurring almost continuously, we are suggesting plate tectonics and the drifting of continents, either apart or together.     

Constraints to the implementation of biological control in Sri Lanka

Sri Lanka is a tropical island with a rich diversity of arthropods, with many species of indigenous natural enemies of economic pests. However, no extensive island wide surveys have been carried out for natural enemies of major crop ecosystems and only a few of the indigenous natural enemies are reported useful for augmentation biological pest control by massive field releases of laboratory-produced insects. Most successful biological control programs on the island are importation (i.e. classical) biological control programs, where established exotic natural enemies control certain pest populations in valuable crops. There is growing interest in the use of native natural enemies in pest management, thus creating a need for intensive research on the ecology of indigenous natural enemies and development of infrastructure and technology to produce natural enemies for augmentation. This paper examines constraints and opportunities for implementation of biological control in Sri Lanka.     

The occurrence of Cryptocoryne and Lagenandra (Araceae) on Sri Lanka

Depending on the species, Cryptocoryne plants grow in different biotopes, viz. spring, river, dark forest, and tree-savanna. The species of Lagenandra are exclusively found in river biotopes. The chromosome numbers found in this study corroborate the numbers previously recorded. Some variation in respect to the morphology of the inflorescence of C. wendtii de Wit and L. ovata (L.) Thwaites is described. A map presenting the distribution of the of Cryptocoryne with their chromosome numbers is included.
The existing populations of Cryptocoryne on Sri Lanka should be protected from further exploitation by plant collectors.     

Comparative studies of vegetative anatomy in the Theaeeae of Sri Lanka

Anatomical characters of the mature leaf blade, petiole, young stem and wood were examined in order to substantiate taxonomic boundaries between genera and species of Theaeeae in Sri Lanka. Two species of Temstroemia , one of Adinandra , four of Eurya and two of Gordonia were studied.
The presence of sclereids in most organs of the plant was found to be a common character within the family. However, three distinct types of sclereid are reported. Two basic types of stomata, anomocytic and gordoniaceous, are recognized. The origin of phellogen in the young stems is pericyclic in Gordonia and subepidermal in the other three genera. The species within these genera also appear to have several distinctive characters of their own. Important wood characters have been tabulated in order to illustrate the primitive and advanced characters. Gordonia , especially, exhibits anatomical features which are quite different from those of Temstroemia, Adinandra send Eurya.