Issue 02

Precise selection of superior hevea genotypes from 2014 hand pollinated progeny

2025-07-17T08:01:46Z

Precise selection of superior hevea genotypes from 2014 hand pollinated progeny Madigasekara, M.M.S.K.; Withanage, S.P.; Liyanage, K.K.; Dharmarathne, T.T.D.; Meegahakumbura, M.K. The hybridization and selection in rubber (Hevea brasiliensis) aim to produce superior genotypes. The perennial nature of Hevea is the major limitation in rubber breeding. Early selection is crucial for strengthening and shortening the breeding program. Therefore, 20 randomly selected individuals of the 2014 hand-pollinated progeny were used for the current morphological, anatomical, biochemical, and gene expression study to identify superior genotypes for future recommendations. The average yield, girth, and bark thickness were measured as morphological characteristics, while sucrose, inorganic phosphorus, thiol, and polyphenol were measured as biochemical characteristics. Dry rubber and total solid content were also measured as diagnostic indicators of latex. The bark anatomical analysis was done with a modified staining protocol. Gene expression analysis was performed using the Catalase (HbCAT) and Superoxide dismutase (HbSOD) genes to evaluate the proneness for Tapping Panel Dryness (TPD). Results indicated that girth (79.8%), bark thickness (60.8%), bark anatomical parameters such as the diameter of latex vessels (60.1%) and the number of latex vessels per unit area (density) (89.2%) positively correlated with rubber yield. The genotypes 2014HP-11, 2014HP-42, 2014HP-78, 2014HP-25, 2014HP-102, 2014HP-35, 2014HP-39, and 2014HP-21 showed comparatively higher morphological characteristics. The genotypes 2014HP-56 and 2014HP-57 showed potential for stimulation due to their high sucrose and low inorganic phosphorus contents. All other genotypes showed below-average performance for commercial recommendations. The optimized bark anatomical screening protocol of the current study clearly stained the secondary latex vessels. Genotypes 2014HP-21 and 2014HP-98 showed higher TPD traits morphologically. Therefore, expression of HbCAT and HbSOD genes was tested. The fold difference value was upregulated in the genotypes 2014HP-21 and 2014HP-98. As a result, these two genotypes are possibly prone to TPD. In conclusion, this study optimized the bark anatomical screening protocol, identified promising high-yielding genotypes and pinpointed the possible vulnerability of two genotypes (2014HP-21 and 2014HP-98) to TPD.

Enhancing mechanized harvesting of mungbean (vigna radiata l.) with defoliation and desiccation using chemical agents in Sri Lanka

2025-07-17T07:36:36Z

Enhancing mechanized harvesting of mungbean (vigna radiata l.) with defoliation and desiccation using chemical agents in Sri Lanka Gunathilaka, W.M.N.D.; Hewavitharana, T.S.; Premarathna, W.G.H.N. In Sri Lanka, mungbean production faces labour shortages and high costs, especially during harvesting. Desiccants and defoliants are essential for drying and preparing crops for mechanical harvesting. The study aimed to identify the most effective chemical agent (defoliant or desiccant) and its optimal concentration for mechanical harvesting, by testing NaCl, Urea (both at 0.25 M, 0.5 M, 0.75 M, and 1 M), and Ethrel at 10⁻⁴ M as separate treatments. It also aimed to evaluate the best timing for applying 0.5 M (40 g/L) NaCl, identified as the most effective in the previous experiment, to maximize harvested yield and assess its long-term effects on soil pH and electrical conductivity (EC). Although the treatments significantly (p < 0.05) impacted seed lightness and germination percentages of seeds immediately after harvesting, with no significant difference (p > 0.05) in the germination one month after harvesting. The study found that 0.5 M NaCl was the most efficient treatment for defoliating and desiccating the mungbean MI 6 variety, achieving significantly highest desiccation and defoliation percentages, maintaining significantly highest germination percentage of seeds and having minimal impact on soil pH and EC. The significantly highest yield was obtained by applying 0.5 M NaCl three days after the due date for the first pick. 0.5 M NaCl application showed minimal impact on soil chemical properties, with no significant changes in pH and EC levels observed over long-term monitoring. Thus, 0.5 M NaCl can be effectively utilized to desiccate and defoliate mungbean plants for easy mechanical harvesting.

Gaps hindering the objectives of fisheries co-management mechanisms in Sri Lanka

2025-07-17T05:45:17Z

Gaps hindering the objectives of fisheries co-management mechanisms in Sri Lanka Ranatunga, R.A.D.S.; De Silva, D.M.A.; Amarasinghe, O.; Kularatne, M.G. The fisheries industry in Sri Lanka plays a vital role in nutritional and food security, job creation, and foreign revenue earnings. Co-management is an important strategy for sustainable fisheries management, where fishers, government bodies, and other stakeholders work together. This study aimed to identify gaps affecting the achievement of 17 FAO good practice indicators related to social and economic goals and objectives of comanagement in Sri Lanka's coastal fisheries sector. A two-stage cluster sampling method was used to select participants: two Fisheries Management Areas were randomly selected from 18 existing areas, followed by three Fisheries Management Committees from each of the chosen Fisheries Management Areas. Data collection involved a structured questionnaire administered to 115 fishers, representing a 40 percent sample of the total membership across six selected Fisheries Management Committees. A desk study of existing laws and regulations, two focus group discussions, and 30 key-informant interviews with officers from the Department of Fisheries and Aquatic Resources, scientists, leading fishermen, and academics were conducted. The study revealed significant gaps affecting the successful implementation of co-management. Key findings include the absence of comprehensive fisheries management and development plans, low participation of women, youth, and other marginalized groups, limited involvement of state and non-state agencies beyond the Department of Fisheries and Aquatic Resources, and weak linkages between co-management programs and economic benefits for fishers. To address these issues, the study recommends prioritizing the development of comprehensive co-management plans, actively involving all stakeholders, including women, youth, and marginalized groups, and creating comanagement platforms that accommodate the diverse interests of all stakeholders.

Development of fish burger patty from spotted triggerfish (canthidermis maculate l.) mince and determination of its nutritional properties and shelf-life

2025-07-17T04:22:24Z

Development of fish burger patty from spotted triggerfish (canthidermis maculate l.) mince and determination of its nutritional properties and shelf-life De Silva, M.W.E.M.N.; Fernando, G.S.N.; Paththuwe Arachchi, M.J.; Jans, H.M. Fish is a popular protein source, and consumer interest in value-added fish products is increasing. In addition to abundant underutilized fish species that are not in demand as fresh fish, this is a sustainable approach to fulfilling protein needs while minimizing the over-exploitation of highly demanded fish varieties such as yellow-fin tuna. Therefore, this study aimed to prepare a burger patty using Spotted triggerfish (Canthidermis maculata L.), a relatively abundant underutilized fish species in the Indo-Pacific region and determine its nutritional properties and shelf-life. Four different formulations of triggerfish mince (FM) and bread crumb (BC) (T1: 62% FM and 10% BC, T2: 58% FM and 14% BC, T3: 54% FM and 18% BC and T4: 50% FM and 22% BC w/w) were prepared while keeping other ingredients constant (28% w/w). Proximate composition, physico-chemical properties and shelf-life analysis were conducted using standard methods. Sensory analysis with 30 semi-trained panellists using a 5-point hedonic scale identified treatment T2 (58% FM:14% BC w/w) as the most preferred fish burger patty. Proximate analysis of T2 revealed 54.92±0.23 g/100 g moisture, 15.5±0.82 g/100 g crude protein, 3.11±0.14 g/100 g crude fat, and 2.28±0.02 g/100 g total ash content. T2 demonstrated significantly higher hardness (p<0.05) than the control sample (commercially available fish burger patty). The total volatile base nitrogen (TVB-N) levels of T2 significantly increased from 14.68 to 26.73/100 g during the storage period. The total plate count was assessed biweekly during storage. The product was absent from E. coli, Staphylococcus aureus, and Salmonella, which were tested at the initial stage. It can be concluded that the developed burger patty, which contains 58% w/w triggerfish mince, is safe to consume after one month, and further studies are required to determine the shelf-life. This product offers a promising alternative to commercially available burger patties, with higher nutritional value in fat, fibre, protein, and energy.