Morphological and molecular characterisation of Aphelenchoides besseyi and A. fujianensis (Nematoda: Aphelenchoididae) from rice and forage grass seeds in Brazil

Morphologically similar Aphelenchoides spp. populations extracted from rice and forage grass seeds from different geographical regions in Brazil were morphologically and molecularly characterised. Overall, the populations studied separated into two groups based on morphological and phylogenetic analyses, referred to herein as ‘Group-rice’ and ‘Group-forage’. Bayesian phylogenetic analyses of SSU, LSU and mtCOI regions strongly supported the presence of two dichotomous groups with Group-rice and Group-forage populations genetically similar to A. besseyi and A. fujianensis , respectively. This study reports the presence of a morphologically similar species to A. besseyi associated with seeds of grasses, but genetically distinct based on three genomic regions, which our results strongly suggest to be A. fujianensis , this being a new geographical record for Brazil. Additional information regarding spicule morphology of male A. besseyi is also reported.