Integrative identification and molecular phylogeny of dagger and needle nematodes associated with cultivated olive in Tunisia

The occurrence and geographic distribution of longidorid nematode species inhabiting the rhizosphere of cultivated olive (cvs. Chemlali and Chétoui) in Tunisia were investigated. Morphological and morphometrical studies identified three Longidorus and six Xiphinema species, with frequencies of prevalence as following: Longidorus africanus (23.0 %), L. euonymus (4.5 %), L. glycines (13.7 %), Xiphinema conurum (13.7 %), X. italiae (36.4 %), X. meridianum (13.7 %), X. pachtaicum (18.2 %), X. robbinsi (9.1 %), and Xiphinema sp. (4.5 %). The three Longidorus species were reported for the first time in Tunisia, in addition to two species of Xiphinema (viz. X. meridianum and X. robbinsi). Molecular characterisation using D2-D3 expansion regions of 28S rRNA and ITS1-rRNA was carried out and Bayesian inference analysis was used to reconstruct phylogenetic relationships among these species and with other longidorids. Twenty-five new D2-D3 of 28S rRNA gene sequences were obtained in the present study, seven for Longidorus and 18 for Xiphinema spp., as well as 14 new ITS1 rRNA gene sequences (seven for Longidorus and seven for Xiphinema spp.).This research was supported by grant KBBE 219262 ArimNET-ERANET FP7 2012-2015 Project PESTOLIVE "Contribution of olive history for the management of soilborne parasites in the Mediterranean basin" from Hellenic Agricultural Organization-DEMETER and Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), grant AGR-136 from "Consejería de Economía, Innvovación y Ciencia" from Junta de Andalucía, and Union Europea, Fondo Europeo de Desarrollo regional, "Una manera de hacer Europa". The fourth author is a recipient of a "Juan de La Cierva" contract from Ministerio de Economía y Competitividad of Spain.Peer reviewe