RESUMO
Seven trichodorid species including a new one (Trichodorus hangzhouensis sp. nov., T. nanjingensis, T. pakistanensis, T. cedarus, Paratrichodorus porosus, Nanidorus renifer and N. minor) were recovered from the rhizosphere of different hosts in 13 provinces of China. Each of the recovered species was characterized based on morphology and molecular data using rRNA gene sequences. Trichodorus hangzhouensis sp. nov. is characterized by its males having medium-sized onchiostyle (46-49 µm) and three ventromedian cervical papillae (CP) anterior to the secretory-excretory (S-E) pore, CP1 located opposite the anterior part of isthmus, S-E pore opposite the isthmus or anterior end of pharyngeal bulb, spicules slightly ventrally curved, relatively small, 33.2 (32.0-34.5) µm long, wider slightly marked capitulum, lamina partially striated without bristles at striation; and females having rounded triangular sclerotized vaginal pieces with tips directed towards vulva, 1.5-2.0 µm sized, at about 1 µm apart, vulva pore-like in ventral view. Phylogenetic analysis based on D2-D3 28S rRNA gene sequences differentiated the new species among Trichodorus species from Europe, Asia and USA which formed a large clade. A review of the distribution of Trichodorus, Nanidorus and Paratrichodorus species revealed that T. cedarus, T. nanjingensis, T. pakistanensis and P. porosus are the most widespread species recorded from different provinces of China. This is the first extensive study of trichodorid species occurring in China.
RESUMO
Longidorus chenisp. n., an amphimictic species recovered from the rhizosphere of Larix principis-rupprechtii and Pyracantha fortuneana in Shanxi and Beijing, China, is described and illustrated. The taxonomic position of L. chenisp. n. among other species within the genus was elucidated using morphometric and molecular data, and phylogenetic relationships were inferred using D2-D3 expansion domains of 28S and 18S rRNA genes by Bayesian Inference (BI) method. The new species is characterised by females with a medium body size (L = 4.9-6.6 mm), a lip region slightly expanded, broadly rounded frontally and laterally, the amphidial fovea broad and symmetrically bilobed at base, odontostyle long and slender (143-168 µm), odonthophore slightly swollen at the base, tail short bluntly conoid to rounded. Guide ring located far posterior from the oral aperture (70-93 µm). Males with two ad-cloacal pairs of supplements preceded by a row of 10-14 ventromedian supplements, with robust spicules measuring 111-126 µm along the median line. Three juvenile stages were present, tail shape of J1 elongate conoid while in J2 and J3 the tail gradually becomes bluntly rounded. Codes for identifying the new species are: A6-B3-C5-D2-E2-F3-G1-H1-I2-J2-K2. Longidorus chenisp. n. belongs to a group of species with a guide ring at the mid-odontostyle position that have a predominantly Asiatic origin. It differs from all of them by a combination of morphological characters and unique sequences of partial 18S and D2-D3 region of 28S rRNA genes. The percentage dissimilarities in partial 18S and D2-D3 28S rRNA genes of L. cheni to the closest species (L. litchii, L. fangi, L. jonesi and L. juglans) were 1.5 %-1.8 % and 16.8-18.3 %, respectively.