M. T. M. Almeida

Phylogenetic relationships, based on SSU rDNA sequences, among the didelphic genera of the family Trichodoridae from Portugal

A survey of virus vector trichodorid nematodes was carried out in the central and northern regions of Portugal. Morphobiometric identification showed the presence of trichodorid species previously reported from Portugal, except for Paratrichodorus porosus, which is reported for the first time in Continental Europe. Small subunit ribosomal DNA (SSU rDNA) sequences of ten different species occurring in Portugal were obtained and a phylogenetic analysis based on their alignment was performed to infer relationships among the different Portuguese trichodorid species and three non-indigenous populations (Nanidorus minor, P. allius and P. teres). The resulting phylogenetic tree is in agreement with the currently accepted classification for Trichodoridae, except for Nanidorus, which clusters together with Trichodorus species, while the genera Paratrichodorus and Trichodorus appear as two distinct groups. A better understanding of the generic groupings in the family Trichodoridae was found. Based on the new molecular analyses we herein accept Nanidorus as a valid genus.

Interspecific differences in the fine structure of the body cuticle of Trichodoridae Thorne, 1935 (Nematoda: Diphtherophorina) and review of anchoring structures of the epidermis

Examination of the fine structure of the body cuticle of Trichodorus cylindricus , T. nanjingensis, T. pakistanensis , T. primitivus, Paratrichodorus anemones , P.hispanus , P.minor , P.pachydermus , P.porosus and P.teres revealed three distinct types, each characterised by differences in layers 4 to 6. A new description is provided for layer 5 and the presence of intracuticular canals and hemidesmosomes as types of anchoring structures for the epidermis are discussed.

Paratrichodorus divergens sp. n., a new potential virus vector of tobacco rattle virus and additional observations on P. hispanus Roca & Arias, 1986 from Portugal (Nematoda: Trichodoridae).

During a survey of trichodorids in continental Portugal, a new trichodorid species, Paratrichodorus divergens sp. n., was found. It is described and illustrated with specimens from the type locality together with additional morphometric data and photographs of specimens obtained from soil samples collected in seven other localities. The species is characterised in the female by distinct drop-like to triangular oblique vaginal sclerotisations diverging outwards and sperm cells usually distributed all through the uteri, and in the male by thin, almost straight, striated spicules, the two posteriormost precloacal supplements being located relatively close to one another and usually opposite the distal third of the retracted spicules, presence of a slightly bilobed cloacal lip and sperm cells with a sausage-shaped nucleus. Paratrichodorus divergens sp. n. most closely resembles P. hispanus Roca & Arias, 1986 with which it often occurs in mixed populations. Additional information is also provided for P. hispanus. Coding of the features of the new species is given following the identification key of Decraemer and Baujard.