Department of Biosystems Technology

Necessity of a National Fungarium and a Culture Collection for Fungi in Sri Lanka

2026-07-14T06:03:08Z

Necessity of a National Fungarium and a Culture Collection for Fungi in Sri Lanka Wijayawardene, Nalin N.; Rajakaruna, Shalini; Dai, Dong-Qin; Jayasekara, Sandhya; Warnakula, Lakshan; Ariyawansa, Kahandawa G.S.U.; Fernando, Eustace Y.; Jayasekera, Primali; Karunarathna, Samantha C.; Singhalage, Darshani; Ukuwela, Kanishka; Jayalal, R.G. Udeni; Jayasinghe, R.P. Prabath K.; Muthumala, Chaminda K.; Madawala, Sumedha; Hewajulige, Ilmi G.N.; Rajawardana, Deepani U.; Ediriweera, Aseni; Ediriweera, Surani; Alawathugoda, Deepani; Rajawatta, K.M. Wathsala; Jin, Xing-Chen; Chandana, E.P. Saman; Nanayakkara, Chandrika; Wijesundara, Siril Sri Lanka is rich in biological diversity, but its fungal diversity is not adequately studied and documented. Recent fungal diversity estimations have predicted that the tropical regions would harbour a large number of novel fungal species. Fungi are ubiquitous, hence it is important to carry out proper investigations to discover novel taxa in different habitats and ecosystems. These taxa represent different life modes i.e. pathogens (of plants, animals and humans), saprobes, endophytes, symbionts (lichens, mycorrhizae), and lichenicolous. Current mycology is mainly based on polyphasic approaches (morphological, DNA based and chemical analyses) to define the species (consolidated species concept). DNA based phylogenetic analyses are widely used in higher level classification. These DNA are mainly extracted from cultures. Depositing a specimen that the fungus is present at a reputed Fungarium and depositing a culture resulted from the specimen at a reputed culture collection is important. The “International Code of Taxonomy of Nomenclature for algae, fungi and plants” stated that it is important to deposit the holotype at a reputed fungarium, while depositing the ex-type culture which is derived from the holotype at a reputed culture collection is also essential. Besides species identification and classification, these specimens and cultures are important in future studies and in genetic resource conservation. In Sri Lanka, currently a national fungarium and a culture collection for fungi do not exist. However, several institutional collections and personal collections are available. In this conceptual paper, we propose to establish a central, national fungarium to deposit holotypes and a culture collection to deposit ex-type cultures while maintaining several regional or mirror collections to replicate the specimens as isotypes and paratypes, and cultures as ex-isotypes and ex-paratypes.

EFFECT OF AZOLLA (Azolla pinnata) BASED ORGANIC FERTILIZER ENRICHED WITH EPPAWALA ROCK PHOSPHATE AND PADDY HUSK ASH ON THE GROWTH AND YIELD OF CHILLI (Capsicum annuum) MICHHY01)

2026-07-14T05:49:28Z

EFFECT OF AZOLLA (Azolla pinnata) BASED ORGANIC FERTILIZER ENRICHED WITH EPPAWALA ROCK PHOSPHATE AND PADDY HUSK ASH ON THE GROWTH AND YIELD OF CHILLI (Capsicum annuum) MICHHY01) Batugedara, B.M.H.S.; Rajawatta, K.M.W.; Karunarathne, K.H.T. Excessive use of chemical fertilizers in agriculture has raised serious environmental and health concerns. In response to the challenges, there is growing interest in sustainable agricultural practices, particularly the use of organic fertilizers. This study was conducted to evaluate the effect of organic fertilizer derived from dried Azolla, blended with Paddy husk ash (PHA) and Eppawala rock phosphate (ERP), on the growth and yield performance of the green chilli variety MICHHY01. The experiment was conducted as a pot trial at the Faculty of Technology, University of Ruhuna using a completely randomized design with four treatments each replicated four times. The treatments consisted of varying ratios of Azolla, ERP, and PHA as follows: T1 (control - 0:3:3), T2 (3:3:3), T3 (6:3:3), and T4 (9:3:3). The basal growing media was prepared by mixing compost, sand, and coir dust at a 2:1:1 ratio (v/v). Growth parameters, including plant height, number of leaves, branches, leaf length, leaf width, and stem diameter, were measured at two-week intervals. Yield parameters, such as number of days to first flowering, number of flowers, number of pods, pod length, pod girth, and fresh weight of pods, were also recorded. The results revealed that the application of Azolla-based fertilizer at a 9:3:3 ratio (T4) significantly enhanced (P<0.05) both vegetative growth and yield performance. T4 exhibited the highest plant height (88.25 ± 1.65 cm), number of leaves (196 ± 4.35), and number of branches (82 ± 4) at the harvesting stage. Additionally, T4 recorded the minimum number of days to first flowering (60.00 ± 0.00 days), the highest number of flowers per plant (84.25 ± 6.30), and the greatest number of pods per plant (45.75 ± 3.52). Pod characteristics, such as pod length (12.375 ± 0.11 cm) and girth (10.360 ± 0.15 mm), were also significantly improved under T4. Furthermore, the highest total yield per plant (108.69 ± 5.19 g) was achieved in T4, demonstrating the effectiveness of the 9:3:3 Azolla-ERP-PHA combination in enhancing chilli production. Comparatively, the control treatment (T1), with a 0:3:3 ratio of Azolla:ERP:PHA, exhibited significantly lower vegetative growth and yield parameters. Therefore, the 9:3:3 combination of Azolla, ERP, and PHA showed considerable potential for enhancing chilli growth and yield under pot conditions; however, field validation and multi-season testing are required before recommending it for commercial cultivation.

Analysis of extreme rainfall and flood events: a case study of the Nilwala River Basin

2026-07-14T05:36:48Z

Analysis of extreme rainfall and flood events: a case study of the Nilwala River Basin Rajawatta, K.M.W.; Ranahansi, H.K.N.; Jayaweera, W.M.C.S. The analysis of extreme hydrological events in river basins and rainfall trends is crucial for reducing vulnerability to flooding and developing flood mitigation strategies. Understanding the correlation between flooding and rainfall patterns helps identify flood-prone areas within the region, plan infrastructure, and improve early warning systems, ultimately mitigating the negative impacts of future flood events and protecting communities and resources. The objective of this study was to determine the relationship between rainfall and anomalous flood occurrence in the Nilwala River Basin (NRB) using statistical analyses. The study was conducted in the southern province of Sri Lanka.While NRB is characterised by monsoon-induced flooding, an unusual flood event was reported recently. Thalgahagoda, Panadugama, Pitabeddara and Urawa represent the four main gaging stations (GS) of NRB. Water level (m) and rainfall (mm) data were collected from each GS for September, October, November, and December over four consecutive years (2021, 2022, 2023, and 2024). The study investigated differences in water levels and rainfall among stations, and the correlation between rainfall and flooding patterns, by analysing the collected data using One-way analysis of variance (ANOVA) and Duncan's multiple range test (DMRT). All stations recorded a significant increment of their highest peak water levels in 2023, compared to previous years: Thalgahagoda (1.69 ± 0.47), Panadugama (5.35 ± 0.99), Pitabeddara (1.84 ± 0.68), and Urawa (1.17 ± 0.51) indicating a potential rise in flood intensity while rapid recovery of water levels was reported in every GSs (1.15 ± 0.39), (4.40 ± 1.07), (1.22 ± 0.55) and (0.63 ± 0.34) respectively in 2024. Results revealed no statistically significant differences in rainfall amounts across the years considered, with only slight variation in mean rainfall values. However, Pitabeddara consistently recorded the highest rainfall in all three years, peaking at 26.46 ± 33.15 mm in 2023. The findings indicate that although interannual rainfall was not significant over the period considered, the downstream section of the basin has been affected by the observed anomalous flood levels. However, the results show a weaker correlation between rising water levels during flood events and consistent rainfall patterns, indicating the potential influence of anthropogenic activities. Overall, the study emphasizes the urgency of enhancing flood management strategies and investigating potential anthropogenic factors, particularly in flood-prone areas such as Thalgahagoda and Panadugama.

Design and implementation of maize (Zea mays L.) growth simulation model for Northwest region in China

2026-07-14T05:32:11Z

Design and implementation of maize (Zea mays L.) growth simulation model for Northwest region in China Rajawatta, K.M.W.; Dongjian, He; Piyaratne, M.K.D.K.; Haidong, Lu A temperature driven maize growth simulation model, NWMSim, was developed by analyzing the quantitative growth of maize on a daily time step and emphasizing the yield prediction with special focus on Northwest region in China. It simulates daily growth and development, total accumulation of dry matter and final grain yield for a single crop season. The simulation runs through seven major phenological stages within the crop cycle including sowing date, germination and emergence, three-leaf unfolding, jointing, booting, spinning and harvesting. Primarily the model development was based on the Growing Degree Days (GDD). The model validation was done using five years field observations (2005, 2006, 2007, 2009 and 2011) collected from Yangling in Northwest region in China. Simulated and observed data were statistically analyzed and compared. The grain yield was slightly over estimated for three cropping cycles (2006, 2007 and 2011) however the coefficient of determination (R2=0.94) has shown a positive agreement. The obtained all results have shown an accurate agreement between simulated and observed values for both development and growth variables. Based on the results and the comparisons of simulated and observed values, it can be used as a prediction tool in maize cultivation and also an economic management tool in economic planning at regional level.