Browsing by Author "Ganeshalingam, A."

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    First comprehensive study on distribution frequency and incidence of seed-borne pathogens from cereal and legume crops in Sri Lanka
    (2022) Ganeshalingam, A.; Daranagama, D. A.
    Sri Lanka as an agricultural country requires seed health testing to rnanage crop diseases. So tar no comprehensive research has been can'ied out for the proper identi fication olseed mycoflora af ltcting the seed quality in Sri Lanka. The present sfudy strives to address this issue by identifying seed-borne fungal pathogens from stored seeds usirg morpho-molecular characterization. Fungal pathogens were isolated lrom surface-sterilized and non-surface sterilized seeds of .,lrachis hypogeu, Or1':a sativa. Ligra radiata, andl4gna srnensls. PCR arnplilication and DNA sequencing olthe intemaL transcribed spacer (ITS) region was carried out for molecular identit-rcation of pathogens. The genaination qualiry of each seed vanety was calculated by pot experiments. Distnbution tiequencies. percentage of germination, and seedling vigor were calculated and analyzed tbr each seed variery tested. In total eighteen isolates were recovered fi'om the fbur seed varieties. Molecular characterization revealed that the fungal isolates recovered from all the four seed varieties belong to seven senera: ,lspergillus, Bipolaris, Daldiuia, lrlacroplromirn, Orbilia, Rhi:opus, and Tuluroml,ces. Rhi:opus spp. showed the highest distribution frequency (15%). Arachis hv-pogea showed the lowest gennination percentage (20%) and lowest seedling vigor index (585). The seeds ofOry:a rativd shorved no gennination probably due to their high incidence offungal pathoqens (loul out ol seven genera). This study is tl.re tlrst comprehensive sLudy analyzing the seed-borne pathogens ol the lour most commonly consurned Sri Lankan cereal and legume crops. Results reported in this study helps to identi[y and implement optimum storage facilities and control such fungal pathogens in future agricultural practices.
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    Observations on Sri Lankan Hypoxylon: a comprehensive morphological study on H. anthochroum, H. flavoargillaceum, and H. piceum
    (Faculty of Science, University of Kelaniya, Sri Lanka., 2021) Palapathwala, P. L. E. S.; Ganeshalingam, A.; Daranagama, D. A.
    Most of the Hypoxylon species are saprobic and usually one of the earliest species to colonize the deteriorated wood. The species of Hypoxylon belonging to the family Hypoxylaceae exhibit a large diversity of fungi in tropical countries like Sri Lanka. However, research on the identification and classification of Hypoxylaceous species is scarce in Sri Lanka. The present study was aimed towards the identification of Sri Lankan Hypoxylaceous species and to produce a stable classification for species nomenclature based on a reliable approach using distinguishable morphological characteristics. An assessment of hypoxylaceous fungi was carried out in the Pilikuththuwa lowland wet zone forest area in Sri Lanka and several Hypoxylon species were identified morphologically, using both macroscopic and microscopic characteristics including features of stromata, ascomata, asci, ascospores, the colour of KOH extractable pigments and culture characteristics. Based on the results the identity of H. anthochroum, H. flavoargillaceum, and H. piceum were confirmed by morphology.