Ceylon Journal of Science (Biological Sciences)
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Item Trimen's taxonomy and a revised handbook to the flora of Ceylon(University of Peradeniya. Peradeniya, 1998) Cramer, L.H.Item Cell suspension cultures of Musa. cv embul (AAB), mondan (ABB) and kolikuttu (AAB)(University of Peradeniya. Peradeniya, 1998) Hirimburegama, K.Three explants (shoot tip, anthers and fruit pulp) of three cultivars of Musa were tested for callus production under different culture conditions and for the development of cell cultures from the callus. It was observed that callus is produced from all three explants of the tested cultivars, both in liquid and semi-solid, under different culture conditions. There was a variation in the morphology of callus and the type of cells in culture. It could be revealed that factors, namely, the explant, growth regulators and light affect the cell types in suspesion, irrespective of the cultivar. Shoot tip of all 3 cultivars produced an embryogenic callus an cell cultures while fruit pulp and anthers produced callus and cell cultures with predominantly parenchyma.Item Bioaccumulation of heavy metals in relation to body length of Oreochromis mossambicus(University of Peradeniya. Peradeniya, 1998) Wijesinghe, M.R.; Jayatunga, Y.N.A.; Hewamanne, R.The nature of the relationship between bioaccumulation of heavy metals and body size (length) in Oreochromis mossambicus from Beira Lake and Weras Ganga in the Colombo District of Sri Lanka was inverstigated. The work was carried out during March - July 1995. The organs; muscle, gills, gonad, kidney and liver were investigated. Analysis was done by the x-ray fluorescence method. There was a significant difference (p0.05) in the metal levels in a paricular organ between the different length classes. A positive ans statistically significant correlation with body length was seen for Cu concentration in the kidney in both the Beira Lake and Weras Ganga samples. A significant positive correlation with body length was observed for Zn in the gill and kidney, and for Fe in the muscle and liver, of the Beria LAke sample. For Cd in the muscle, a significant negative correlation with length was observed in the Beria Lake sample. This is noteworthy since the muscle is the tissue that is normally consumed. In the same site there was also accumulation of lead in one of the smaller size classes.Item Physico-chemical characteristics of mosquito breeding habitats in an irrigation development area in Sri Lanka(University of Peradeniya. Peradeniya, 1995) Amerasinghe, F.P.; Indrajith, N.G.; Ariyasena, T.G.Item Spinal conformation of domesticated Sri Lankan elephants(Elephas maximus maximus)(University of Peradeniya. Peradeniya, 1998) Godagama, W.K.; Wemmer, C.; Ratnasooriya, W.D.The aim of this study was to investigate scientifically whether the five spinal conformations (Types 1 to 5) described for the Burmese elephant (Elephas maximus birmanicus) are also present in the Sri Lankan elephant (Elephas maximus). This was done using 140 domesticated elephants and the GAle's five-description system. The results showed thst the five spinal conformation types described for Burmese elephant are also present in the Sri Lankan elephant. Out of the 140 elephants, 23(16perc.) had type 1, 48 conformation. The five types p=0.001, d.f.=4). Further there was a significant difference (fisher's Exact test; p=0.001, d.f.=4) between the number of male elephantas and female elephants falling into the five different types of spinal conformationItem The body condition of Sri Lankan domesticaded elephants (Elephas maximus maximus)(University of Peradeniya. Peradeniya, 1998) Godagama, W.K.; Wemmer, C.; Ratnasooriya, W.D.The body condition of domesticated Sri Lankan elephants has not been scientifically evaluated although many believe that it is poor. The objective of this study was to evalute the body condition of domesticated elephants in Sri Lanka using an index developed by Wemmer and Krishnamurthy (1992). This method of assessing relies on visual assessment and numerical scoring of six criteria (temporal depression, scapula, thoracic region, flank area, lumbar vertibrae and pelvic bone) resulting in a scale of 0-11. The study was conducted between 1st April 1993 and 1st April 1994 in 13 administrative districts using 140 domesticated elephants. The results show that the mean body condition index of the present day domesticated elephants is 6.95+/- 0.26 points (mean +/- SEM). MAles had significantly lower body condition index (6.63+/-0.22 points) than that of females (7.3+/-0.21points) and there was no significant (r=0.398, p=1, n=140) correlation between the age and the body condition index of elephants. Further, the body condition index was not significantly different between the elephants which were owned by private individuals or temples and dewales (p=0.71) and maintained by the mahouts or the owners(p=0.21)Item Root nodulation and fungal associations of two common herbaceous leguminous weeds in the university of Peradeniya(University of peradeniya. Peradeniya, 1995) Abeyagoonasekera, R.M.K.; Balakrishnan, K.T.Item Preliminary observations on graminaceous aphids (Homoptera: Aphididae) of the Peradeniya University Park(1995) Wijerathna, M.A.P.; Edirisinghe, J.P.Fourty two grass species, mostly weeds, found within about 70 heactares of the Peradeniya University Park, were examined for aphids.Eight species of aphids were recorded from 21 grass species in the study area. Two of the aphid species collected, Hysteroneura setariae (Thomas) and Rhopalosiphum Padi (L.) had not bee previously recorded from Sri Lanka.Item Diel oviposition activity of Armigeres subalbatus (Diptera, Culicidae)(1995) Weerasekara, S.K.; Amarasinghe, F.P.The diel oviposition activity of Armigeres subalbatus (Coquillett) was investigated under natural conditions in a shaded home-garden habitat in Kandy. A total of 28,771 eggs of this species were collected in an ovitrap during 10 diel cycles carried out in December 1987 - January 1988. Oviposition activity was biphasic, with a major peak at sunset and a secondery peak of sunrice. The diel oviposition profile was similer to the biting profile of the species and it appears that rapid changes in light intensity associated with the crepuscular periods act as cues controlling maor rhythmic activity patterns of the species.