http://dr.lib.sjp.ac.lk/handle/123456789/30 Sun, 26 Apr 2026 10:18:20 GMT 2026-04-26T10:18:20Z http://dr.lib.sjp.ac.lk/handle/123456789/8898 DNA Barcoding and domestication of three Lentinus species in Sri Lanka Miriyagalla, S; Silva, I; Udayanga, D; Manamgoda, D Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/8898 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/8897 Molecular phylogeny reveals novel evolutionary lineages of Curvularia from Sri Lanka Ferdinandez, H.S; Udayanga, D; Deshappriya, N; Munasinghe, M; Manamgoda, D Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/8897 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/7824 DIRECT ORGANOGENESIS OF STEVIA REBAUDIANA IN VITRO USING NODAL EXPLANTS Gunasena, K.M.; Senarath, S. Stevia rebaudiana Bertoni is a medicinal herb belonging to the family of Asteraceae. It is a natural sweetener plant, which is estimated to be 300 times sweeter than cane sugar. In this study, reliable protocol was developed for direct organogenesis of S. rebaudiana using in vitro derived nodal explants. Seeds were collected from mother plants and they were surface sterilized. To optimize the surface sterilization procedure, dark color (fertile seeds) seeds were surface sterilized using different concentrations and in different exposure time of carbendazim and sodium hypochlorite (Clorox). Out of different combinations 0.2% carbendazim for 5 minutes, 10% sodium hypochlorite for 10 minutes and 70% ethanol each followed by two successive washings in sterile distilled water was found to be the best for surface sterilization. Two sets of seeds (fresh, stored) were cultured on MS basal medium supplemented with different concentrations of GA3 for seed germination. According to the results seed viability was lost with time and it affected seed germination. Seed germination was not affected by GA3, but seedling height was affected by it. Seeds germinated on MS medium supplemented with 3.0 mg/L GA3 showed the highest seedling height after 10 days. MS basal medium supplemented with different concentrations of BAP and Kin were tested for shoot bud and multiple shoot induction. Out of different media Ms basal medium supplemented with 2.0 mg/L BAP was found to be the best medium for shoot bud and multiple shoot induction within 60 days. Keywords: Stevia rebaudiana, surface sterilization, seed germination, shoot induction, direct organogenesis. Sun, 01 Jan 2017 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/7824 2017-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/6909 SSR markers reveal the population structure of Sri Lankan yellow dwarf coconuts (Cocos nucifera L.) Kamaral, L.C.J.; Dassanayaka, P.N.; Perera, K.L.N.S.; Perera, S.A.C.N. Attached; World coconut germplasm has been classified broadly as tall and dwarf coconuts based on palm stature. Dwarf coconuts are predominantly self-breeding purelines hypothesised to have derived from tall coconuts. Dwarfs are categorized as yellow, green, red and brown on the colour of epicarp and are important as parents in hybridization of coconuts for desirable traits. Sri Lankan yellow dwarfs (SLYD) were observed to have uncommon phenotypes which were not previously reported for dwarf coconuts in the world, and this study was conducted to elucidate the population structure of SLYD. One hundred and two randomly selected SLYD individuals were categorized into three morphological groups and their genotypes were derived at 30 SSR loci. Genotypic data were analysed in PowerMarker 3.2.5 and Structure 2.3.4 software to derive the genetic diversity and the population structure. Unexpectedly high numbrs of alleles, genotypes, gene diversity and heterozygosity values were recorded for SLYD. Four populations were identified within SLYD under admixture model and their morphological variations were determined. Cross pollination between the dwarf and tall coconut varieties followed by the fixing of alleles by subsequent self-pollination was hypothesised to be the cause for the emergence of new genetic groups within dwarf populations. The study demonstrated the formation of new genotypes upon limited cross pollination of even naturally self-pollinating tree crops. The information will be useful for developing strategies for germplasm conservation, practical coconut breeding and determining the domestication and evolution of dwarf coconuts Mon, 14 Nov 2016 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/6909 2016-11-14T00:00:00Z