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Title: New records of Lasiodiplodia theobromae in seeds of Tetrapleura tetraptera from Nigeria and fruit of Cocos nucifera from Mexico

item Dugan, Frank
item Lupien, Shari
item OSUAGWU, A - University Of Nigeria
item UYOH, E - University Of Nigeria
item OKPAKO, E - University Of Nigeria
item Kisha, Theodore

Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2015
Publication Date: 6/1/2015
Citation: Dugan, F.M., Lupien, S.L., Osuagwu, A.N., Uyoh, E.A., Okpako, E., Kisha, T.J. 2015. New records of Lasiodiplodia theobromae in seeds of Tetrapleura tetraptera from Nigeria and fruit of Cocos nucifera from Mexico. Journal of Phytopathology. 164: 65–68. doi: 10.1111/jph.12384.

Interpretive Summary: Lasiodiplodia theobromae is a plant pathogen and endophyte widely distributed in tropical, sub-tropical and warmer temperate regions. It is one of several species in the genus, some of which are very closely related to it and are best regarded as formerly cryptic species. During research being performed at USDA-ARS WRPIS on Tetrapleura tetraptera (a medicinal, tree-sized legume native to West Africa) it was noticed that seeds of the plant were commonly colonized by the fungus, and that germination of the seeds was strongly inhibited. At the same time, we noticed that fruits of coconut (Cocos nucifera), originating in Mexico and sold in local retail outlets were often colonized and degraded by the fungus. We identified the fungus by morphological and molecular criteria, conducted pathogenity tests with coconut (verifying pathogenicity to coconut of isolates from coconut and Tetrapleura), and demonstrated statistically the negative correlation between colonization of seed and ability of seed to germinate. Cocos nucifera is currently represented in the USDA-ARS Germplasm System. Seedlings of T. tetrapleura have been sent to the National Germplasm Repository in Miami, Florida. To our knowledge, this is the first report of L. theobromae from Tetrapleura, and the first report of the fungus from coconut fruit in Mexico.

Technical Abstract: The cosmopolitan warm-climate plant pathogen Lasiodiplodia theobromae was isolated from two sources: Seeds of Tetrapleura tetraptera from Nigeria and fruits of Cocos nucifera from Mexico; the former instance is novel for host, the latter a novel geographic record for infection of coconut fruits. Percent germination of T. tetraptera seeds was negatively correlated with percent infection by the fungus. Repeated tests with isolates from both coconut and Tetrapleura confirmed pathogenicity of all tested isolates to coconut fruit.