Confirmation of Fusarium solani as the causal agent of die‐back of Dalbergia sissoo in Nepal

Abstract

Plant PathologyVolume 56, Issue 6 p. 1041-1041 Free Access Confirmation of Fusarium solani as the causal agent of die-back of Dalbergia sissoo in Nepal D. D. Shakya, D. D. Shakya Central Department of Botany, Tribhuvan University, Kirtipur, Kathmandu; and E-mail: ddshakya@hotmail.com Accepted 22 December 2006 at http://www.bspp.org.uk/ndr where figures relating to this paper can be viewedSearch for more papers by this authorP. B. Lakhey, P. B. Lakhey Mangal Bazar, Lalitpur, NepalSearch for more papers by this author D. D. Shakya, D. D. Shakya Central Department of Botany, Tribhuvan University, Kirtipur, Kathmandu; and E-mail: ddshakya@hotmail.com Accepted 22 December 2006 at http://www.bspp.org.uk/ndr where figures relating to this paper can be viewedSearch for more papers by this authorP. B. Lakhey, P. B. Lakhey Mangal Bazar, Lalitpur, NepalSearch for more papers by this author First published: 06 November 2007 https://doi.org/10.1111/j.1365-3059.2007.01637.xCitations: 7 AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Sissoo (Dalbergia sissoo) is an important multipurpose timber tree, widely planted in South Asia. Die-back is considered an epidemic disease of sissoo in this region. The typical symptoms of die-back are characterised by yellowing of leaves, followed by browning and shedding of leaves from the top. In Nepal, this disease was noted in plantation sites in Kailali District in 1989 (Thapa, 1990). Since then the disease has been noted in almost all sissoo growing areas of Nepal and has now become an epidemic and is spreading steadily. Fungal species, such as Fusarium solani, F. oxysporum and Ganoderma lucidum have been reported as associated with this disease (Parajuli et al., 2000, Joshi & Baral, 2000), although pathogenicity tests have not been completed to confirm their role in die-back disease (Anonymous, 2000). Samples of roots, twigs and pods were collected from die-back affected trees from breeding seed orchards in Dharan, Sauraha and Tilkane established by Tree Improvement and Silviculture Component (TISC), and Bishnu Devi Community forest in Saptari district. Fusarium solani was consistently isolated from roots of affected trees and was also isolated from pods and living twigs of diseased trees. The identification of a single spore culture of F. solani TiRo7 has been confirmed by Global Plant Clinic, CABI Bioscience, UK and deposited in the Genetic Resource Collection (GRC), under IMI Ref. No. 394682. Single-spore isolates were inoculated into 4-month-old sissoo saplings. On the stem surface at 5 cm above the soil level, a tangential cut, about 1 cm long, was made with a sterilised scalpel so that it slightly wounded the xylem. A small amount of 7-day-old F. solani culture was inserted into the slit and bound by grafting tape. The control saplings were also treated in the same way, but without administering the fungus. All the saplings inoculated with F. solani isolates developed typical symptoms of die-back within two weeks and reisolation of F. solani was readily made from these seedlings, thus confirming pathogenicity. All saplings kept as controls remained healthy. The consistent isolation of F. solani from roots of affected trees, the development of die-back symptoms on inoculated plants and reisolation of F. solani from these inoculated plants confirms this pathogen as the primary cause of sissoo die-back in Nepal. Acknowledgements The authors are grateful to HMGN/NARMSAP/DANIDA Tree Improvement and Silviculture Component (TISC) for providing partial funding. References Anonymous, 2000. Outcome of Seminar. In: S Appanah, G Allard, SM Amatya, eds. Proceedings of Sub-regional Seminar on Die-back of Sissoo, Kathmandu, Nepal, 25–28 April, 2000. Bangkok, Thailand: FAO/FORSPA, 57– 60. Google Scholar Joshi RB, Baral SR, 2000. A report on die-back of Dalbergia sissoo in Nepal. In: S Appanah, G Allard, SM Amatya, eds. Proceedings of Sub-regional Seminar on Die-back of Sissoo, Kathmandu, Nepal, 25–28 April, 2000. Bangkok, Thailand: FAO/FORSPA, 17– 22. Web of Science®Google Scholar Parajuli AV, Bhatta B, Adhikari MK, 2000. Die-back of Dalbergia sissoo in the Terai belt of Nepal. In: MS Bista, RB Joshi, SM Amatya, AV Parajuli, MK Adhikari, HK Saiju, R Thakur, K Suzuki, K Ishii, eds. Proceedings of 8th International Workshop of BIO-REFOR, Kathmandu, Nepal, 1999. Tokyo, Japan: IUFRO/SPDC BIO-REFOR, 27– 30. Google Scholar Thapa F, 1990. Dieback threatens Dalbergia sissoo. Farm Forestry News 3, 8. Google Scholar Citing Literature Volume56, Issue6December 2007Pages 1041-1041 ReferencesRelatedInformation