Browsing by Author "Wickramasinghe, G.A."

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    Investigating the Presence of Candidatus Liberibacter Asiaticus in Murraya Koenigii and Citrus Spp. from Selected Areas in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2014) Wickramasinghe, G.A.
    Citrus Greening (CG) disease is the most detrimental bacterial disease for citrus, caused by Candidatus Liberibacter asiaticus (CLas). In Asia, CG is mainly transmitted by Asian Citrus Psyllid which is recognized as a major pest in Murraya koenigii (curry leaves). This study was employed to investigate the presence of CLas in Murraya koenigii and Citrus spp. in some selected locations where fresh curry leaves are harvested for exporting. Leaf samples of curry leaves and Citrus spp. were collected from Anuradhapura, Puttalam and Badulla areas. The presence of CLas in leaf samples were identified by amplification of 1160 by fragment of 16s rRNA coding gene of CLas by using 011 and OA 1 as forward primers and 012c as common reverse primer and by amplification of 703 by and 669 by fragments of rp1KAJL-rpoBC operon gene of CLas using forward primer A2 and reverse primer J5. All the tested Curry leaf samples from all locations did not produce any amplicon indicating zero presence of CLas, while Citrus leaf samples produced amplicons in all three areas indicating the presence of CLas. Citrus in Anuradhapura area displayed the lowest percentage (40%) of amplicon, while the highest percentage of 80 was observed from Badulla area. Citrus in Puttalam area showed 53% presence of amplicons. Results indicate that, within three selected areas, CLas is totally absent in curry leaves, while CLas presence is detected in Citrus spp. in same fields. CG is restricted to Citrus spp. in Anuradhapura, Puttalam'and Badulla areas and Murraya koenigii (curry leaves) is free of CLas as host. There is a potential to export fresh curry leaves from those areas, due to the absence of CLas in curry leaves. Keywords: Citrus Greening, Candidatus Liberibacter asiaticus, Murraya koenigii
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    Investigating the Presence of Candidatus Liberibacter asiaticus in Murraya koenigii and Citrus spp. from Selected Areas in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2019) Wickramasinghe, G.A.; Subhashini, M.H.A.D.; Alwis, L.M.H.R.
    Citrus Greening (CG) disease is the most detrimental bacterial disease for citrus and it is caused by Candidatus Liberibacter asiaticus (CLas). In Asia, CG is mainly transmitted by Asian Citrus Psyllid (ACP) which is recognized as a major pest in Murraya koenigii (curry leaves). This study was carried out to investigate the presence of CLas in Murraya koenigii and Citrus spp. in selected locations, where fresh curry leaves are harvested for exporting. Leaf samples of curry leaves and Citrus spp. were collected from Anuradhapura, Puttalam and Badulla areas. The presence of CLas was tested in twenty-seven leaf samples of each plant using DNA extraction by modified CTAB method followed by Polymerase Chain reaction (PCR). CLas presence was detected by amplification of 1160 bp fragment of 16s rRNA coding gene of CLas by using OI1 and OA1 as forward primers and OI2c as common reverse primer and by amplification of 703 bp and 669 bp fragments of rplKAJL-rpoBC operon gene of CLas using forward primer A2 and reverse primer J5. None of the curry leaf samples produced any amplicon indicating zero presence of CLas, while Citrus leaf samples produced amplicons in all three areas indicating the presence of CLas. Citrus in Anuradhapura area displayed the lowest percentage (40%) of presence, while the highest percentage (80%) was observed from Badulla area. Citrus in Puttalam area showed 53% of presence. Results indicated that, within three selected areas, CLas is totally absent in curry leaves, while CLas presence is detected in Citrus spp. in same fields. CG is restricted to Citrus spp. in Anuradhapura, Puttalam and Badulla areas and Murraya koenigii (curry leaves) that is host for ACP is free of CLas.