http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/656 2026-04-08T02:20:42Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/930 SCREENING FOR SWEET POTATO (Ipomoea Batatas L.) LEAF CURL VIRUS (SPLCV) AND ITS ELIMINATION USING THERMOTHERAPY-MERISTEM TIP CULTURE TECHNIQUE Arkorful, E; Appiah, A. S; Obiatey, H. Dzahini Despite its high potential for food security, production of sweet potato (Ipomoea batatas L.) is constrained by viruses which reduce yield by 90 %. It is, therefore, essential to detect and eliminate these viruses in elite clones before dissemination to farmers. In this study, we used visual symptomatology and polymerase chain reaction (PCR) techniques to detect Sweet potato leaf curl virus (SPLCV) and eliminated the virus using thermotherapy-meristem tip culture. Visual symptomatology revealed virus associated symptoms, including vein clearing, interveinal chlorosis, chlorotic spots, upward leaf curling, leaf narrowing, purpling, blistering and leaf yellowing in all 22 accessions grown on the field. The disease incidence varied between accessions with US003 having the lowest (20 %), while ten accessions had the highest (90 %). The severely diseased accessions were tested for SPLCV using PCR technique. The technique detected the virus in 30 % of the accessions. Plants that tested positive to PCR assay were grown in the chamber at 35 OC for 4 weeks followed by meristem culture. The regenerants were indexed for SPLCV. Fifty-two percent (52.4 %) of the regenerants were successfully cleaned of the virus. Virus indexing and elimination will enhance the dissemination of disease-free planting materials to farmers. 2015-01-01T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/924 EFFECT OF PRETREATMENTS ON QUALITY OF MINIMALLY PROCESSED COOKING BANANA VARIETY ALUKESEL (Musa acuminata × Musa balbisiana, ABB GROUP) Siriwardana, H; Abeywickrama, K; Kannangara, S Cooking banana is a vegetable which can be stored for longer periods in intact form but undergoes browning soon after slicing. A study was undertaken to evaluate the effect of selected pretreatments in maintaining quality of minimally processed cooking banana variety Alukesel. Minimally processed Alukesel was subjected to pretreatments of ascorbic acid (3%), citric acid (3%), ascorbic acid (2%), citric acid (2%), citric acid + ascorbic acid (1.5% each), sodium metabisulphite (2%) and distilled water (control), packed in polystyrene packages and stored at 5-70 C for a week. The effects of pretreatments on sensory and physicochemical properties (percentage weight loss, changes in firmness, pH, Total Soluble Solids (TSS) and Titratable Acidity (TA)) were evaluated on day 0 and day 7, while browning was assessed using a spectrophotometric method. Pretreatments had a significant effect on physicochemical and sensory attributes of minimally processed cooking banana compared to control. Ascorbic acid (3%), citric acid (3%) and citric acid + ascorbic acid (1.5% each) pretreated cooking banana obtained higher ranking values for sensory properties (appearance, colour, odour, flavour, taste and overall acceptability) while the same three pretreatments and sodium metabisulphite (2%) pretreatment effectively controlled enzymatic browning. This research revealed that pretreatments of ascorbic acid (3%), citric acid (3%) and citric acid + ascorbic acid (1.5% each) were more successful in retaining quality of minimally processed cooking banana for one week in cold storage. It could be concluded that Alukesel treated as above can be considered as a potential value added sale item at local supermarkets where cold storage facility is available. 2015-01-01T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/921 GROUND WATER QUALITY NEAR MUNICIPAL SOLID WASTE DUMPING SITE AT THIRUPPERUMTHURAI, BATTICALOA Sugirtharan, M; Rajendran, M Groundwater is a precious natural water resource considered as a readily available and safe source of water for domestic, agriculture and industrial uses. In Sri Lanka, groundwater is being polluted due to various human activities. Improper solid waste management is one of the major sources of environmental pollution deteriorating groundwater quality around landfill sites. In this view, present study was carried out to assess the impact of existing landfill site on groundwater quality at Thirupperunthurai, Batticaloa. In order to achieve this, 20 well water samples around landfill site at different distance were analyzed. Parameters analyzed are pH, EC, TDS, BOD, COD, total hardness, phosphate, nitrate, copper, lead and coliform population. Results revealed that concentration of all the parameters except for pH, are higher than acceptable limits for safe drinking water. The distance from the landfill site also influences on groundwater quality. Overall, the groundwater is highly polluted due to existing landfill site in this study area. Therefore, the relevant authority should take immediate measures to rescue this area. 2015-01-01T00:00:00Z http://repo.lib.sab.ac.lk:8080/xmlui/handle/123456789/918 INTERACTION EFFECT OF HEAT SHOCK AND SEED PRIMING ON STORABILITY OF AGROPYRON ELONGATUM Bahreh, M. Akbarpour; Zadeh, F. Sharif; Abbasi, A Priming improves germination rate and seed vigor but reduces longevity of seeds. We examined the possibilities of obatining primed seeds with maintaining high germination quality but with longevity much the same that seeds are not treated. In this study were used different priming treatments for Agropyron elongatum. Then primed seeds were placed at different levels of heat shock. And then all treatments and unprimed seeds were evaluated in standard germination and accelerated ageing test. We found that the desired longevity could be obtained by keeping the seeds under heat shock for four hours at 40o C, after a priming treatment. Decreasing germination and seedling vigour in hydro and hormonal priming did not happaen again due to such a treatment. In addition, following priming, heat shock affects the initial quality of primed seeds in some treatments. Optimal temperature was strongly duration dependent. The method was applied to obtain primed seeds without loss of storability is very similar to those used to induce desiccation tolerance in germinated seeds and acquired thermotolerance in plant vegetative tissues. 2015-01-01T00:00:00Z