Browsing by Author "Jayasekara, A."

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Morphological and molecular identification of fungi for their association with postharvest fruit rots in some selected citrus species
(2022) Jayasekara, A.; Daranagama, A.; Kodituwakku, T.D.; Abeywickrama, K.
Purpose: The availability of fresh Citrus fruits is limited by their susceptibility to invasion by microbial pathogens which leads to cause serious postharvest losses. The present study was carried out to isolate and morphologically identify postharvest fungal associations from selected Citrus fruit species (C. sinensis, C. limon, C. crenatifolia and C. medica) and to confirm their identity by molecular characterization. Research method: Postharvest fungal associations of selected Citrus fruit species were isolated, and identification was done based on morphological characteristics. Confirmation of fungal associations was done through phylogenetic analysis of newly generated ITS sequencing data. Further, frequency of occurrence of each fungal isolate was calculated in three different districts in Sri Lanka. Findings: From the morphological and molecular identification, Collectrichum fructicola, Collectrichum gloeosporioides, Lasiodiplodia theobromae, Aspergillus niger and Pestalotiopsis sp. were recorded from C. sinensis. Neofusicoccum parvum, Collectrichum gigasporium and Aspergillus clavatus were isolated from C. crenatifolia. Further, Lasiodiplodia theobromae and L. pseudotheobromae were the only fungal association isolated from C. limon and C. medica fruit species, respectively. It is worthwhile noting that this is the first report of association of the C. gigasporium and Pestalotiopsis sp. from Citrus fruits in Sri Lanka. Research limitations: Since this research was mainly focused on the isolation and identification of the potential fungal associations, pathogenicity evaluation could not be carried out. Originality/Value: Findings of potential disease causative agents in citrus will be valuable for agriculture sector, to adopt and practice effective strategies to minimize postharvest losses of citrus fruits.
Physiological disorders of selected Citrus fruit species in Sri Lanka and their effect on fruit quality
(JOURNAL OF HORTICULTURE AND POSTHARVEST RESEARCH, 2021) Jayasekara, A.; Abeywickrama, K.; Daranagama, A.; Kodituwakku, T.
Purpose: This study was conducted to identify the physiological disorders and their symptoms of selected Citrus fruit species (C. sinensis, C. limon and C. crenatifolia). Furthermore, it was aimed to determine whether physicochemical and sensory properties were affected by physiological disorders. Research method: Citrus fruits with physiological disorders were observed separately for visible changes and characters were recorded and photographed. Moreover, Citrus fruits with physiological disorders were analyzed for physicochemical and sensory properties. Findings: Many physiological disorders were recorded from three Citrus fruit species including chilling injury, sun burn, stem-end rind breakdown, oleocellosis, rind disorder, puff and crease, granulation, wind injury, peteca, fruit splitting and fruit cracking. Based on the overall result of sensory analysis, it can be concluded that most of the physiological disorders in studied Citrus species appear on the peel but not adversely affect the edible internal portion of the fruits. Physicochemical properties of C. limon are not adversely affected by physiological disorders whereas C. sinensis and C. crenatifolia are affected by physiological disorders. Limitations: Availability of selected Citrus fruit species throughout the year is limited due to their seasonality. Originality/Value: This study provides novel information about the physiological disorders of some Citrus species in Sri Lanka and other parts of Asia and a future potential exists in controlling these disorders to provide healthy and quality fruits to the market.
The long-term impact of postcholecystectomy major bile duct injury on liver stiffness
(BioMed Central, 2024-11) Jayasekara, A.; Tillakaratne, S.B.; Dasanayake, U.; Gishanthan, S.; Siriwardana, R.C.
INTRODUCTION Iatrogenic bile duct injuries (BDI) are a devastating complication. Long-term impact of corrective hepaticojejunostomy (HJ) for such injuries on post -surgery liver stiffness is lacking. Hence the aim of this study was to explore the extent of hepatic fibrosis in a cohort of patients with Strasberg E bile duct injuries who underwent HJ after a minimum follow-up of six months.METHODS Out of 50 BDI presented over a period of 10-years, 19 patients with Strasberg type E, injuries that underwent HJ and completed a minimum 6-month follow-up [65.5 (7 -108)] period were selected. Data were prospectively collected on liver functions and liver stiffness was assessed using a Fibroscan. Their liver stiffness and degree of fibrosis was compared with (n = 38) age, gender and comorbidity matched controls.RESULTS The median age was 47 (30-70) years, with 63% females. Primary HJ was performed in 84%, with a median time from injury to HJ of 7 (1-39) days. The total bilirubin was 16.5 (11.2) µmol/L, Alkaline Phosphatase was 102 (27.2) U/L, and Platelet count was 256 (77) x 103. Liver stiffness (median 6.4 kPa) did not significantly differ from controls (5.3 kPa). Fibrosis assessment revealed comparable distribution of F0 to F3 fibrosis between the study and control groups (F0/F1: 68.4% vs. 84.4%, F2: 10.5% vs. 9.4%). However, all three patients with right hepatic artery injury (p = 0.003) and three of five patients with bile duct stricture had F3/F4 fibrosis.CONCLUSIONS Major BDI repair demonstrates comparable liver fibrosis in the absence of artery injury and anastomotic strictures. Measuring liver fibrosis could be valuable in the presence of arterial injuries or anastomotic strictures.