The plant-parasitic nematode Longidorus poessneckensis from the Czech Republic was morphologically and molecularly characterised. Molecular analyses were carried out using mitochondrial DNA (cytochrome c oxidase subunit 1-cox1) and ribosomal DNA (ITS2-second internal transcribed spacer, 18S gene and D2/D3 expansion segments of the 28S gene), which were amplified and sequenced. Phylogenetic relationship of L. poessneckensis with three morphologically closely related species, i.e. L. macrosoma, L. helveticus and L. uroshis, was inferred by using maximum likelihood and maximum parsimony methods, with a female of Xiphinema diversicaudatum and a bivulval female of X. vuittenezi as outgroups. All multiple alignments yielded similar basic trees supporting the uniqueness of L. poessneckensis and the validity of the four Longidorus species identified using morphological characters. Phylogenetic analyses revealed that L. poessneckensis is more closely related to L. macrosoma and L. helveticus than to L. uroshis. High inter-population diversity (19%) was observed across the cox1 gene between two populations of L. poessneckensis.

Plant parasitic nematodes of the family Trichodoridae cause substantial yield losses in many agricultural crops. Rapid and accurate identification of trichodorids to the species level is critical for selection of appropriate measures for control. This study analysed 99 sequences of the D2-D3 expansion segments of the 28S rRNA gene and 131 sequences of the 18S rRNA gene from the stubby nematodes belonging to the genera Nanidorus, Paratrichodorus and Trichodorus. Species delimiting was based on the integration of morphological identification, which is not provided in the present article, and molecularbased phylogenetic inference and sequence analysis. Twenty-two valid species and several species complexes were identified among nematodes included in the analysis. PCR-RFLPs of the partial 18S rDNA and the D2-D3 expansion segments of the 28S rDNA were tested and proposed for identification of these nematodes. Gel PCR-RFLP profiles and tables with restriction fragment lengths for several diagnostic enzymes are provided for identification. Some problems of taxonomy and phylogeny of nematodes of the family Trichodoridae are also discussed.

Genetic analyses using sequences of partial cytochrome c oxidase subunit 1 (cox1) gene of mitochondrial DNA were conducted to determine the extent of genetic variation within and among Xiphinema diversicaudatum, X. pachtaicum, X. simile and X. vuittenezi populations. Pairwise distance among the four species was 22.5 to 31.2%. Four different sequence variants of cox1 were determined among six populations of X. diversicaudatum and three variants among three populations of X. simile. Nucleotide variation was detected at 18 of 414 bp (1.9 to 2.7%) in X. diversicaudatum and 4 of 435 bp (0.2 to 0.9%) in X. simile. All changes were at silent sites. No nucleotide variation was detected within three populations of X. pachtaicum and within three populations of X. vuittenezi.

Diazotrophic rhizobacteria, trigger and enhance plant growth as well as yield through various mechanisms, so their use can reduce the application frequency of chemical fertilizers. Indole-3-acetic acid (IAA), a most common natural auxin influences several physiological processes of the plant's health. The present study is aimed to optimize the conditions for IAA production, along with assay for plant growth promoting traits of Bacillus subtilis DR2 (KP455653), which is a diazotrophic Gram positive, rod bacterium, isolated from rhizosphere of road side weed, Eragrostis cynosuroides from Danapur, Patna, Bihar, India. The screening for IAA production was done in JNFbˉ broth with tryptophan (1 g.l-1) and without tryptophan at pH 5.8, 30±2 °C temperature and 48 h incubation. 137.81 µg.ml-1 and 100.26 µg.ml-1 IAA was produced in Trp + and Trpmedia, respectively. Under various optimized conditions, maximum IAA was produced at 96 h incubation (137.81 µg.ml-1), 35 °C temperature (141.92 µg.ml-1), pH 7 (158.79 µg.ml-1), mannitol as carbon (160.85 µg.ml-1) and ammonium sulfate as nitrogen (162.93 µg.ml-1) sources with tryptophan at final concentration of 1.2 µg.ml-1 (168.09 µg.ml-1), which enhanced the production by 1.2 fold. The findings suggest that B. subtilis DR2 is a potent organism to be used as biofertilizer. 

43 SummaryA nematode survey was carried out in South Moravia and Bohemia (Czech Republic) to assess the occurrence of Xiphinema in the rhizosphere of fruit orchards. Sixty six orchards in South Moravia and seven in Bohemia were studied during the years 2003 and 2004. Four Xiphinema species (X. diversicaudatum, X. pachtaicum, X. simile and X. vuittenezi) were recorded. X. simile constitutes a first record for the nematodes fauna of the Czech Republic.

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Longidorus helveticus was found at two out of 285 sampling sites for the first time in the Czech Republic. Females, males and juvenile stages were analyzed morphologically and morphometrically. The morphological identification of samples was verified by polymerase chain reaction using a species specific primer. Four markers of ribosomal DNA (18S, ITS1, ITS2, D2-D3 expansion segments of 28S rRNA) and two markers of mitochondrial DNA (cox1 and nad4) were sequenced and analyzed and compared with published gene sequences of other populations of L. helveticus. The partial mitochondrial cytochrome coxidase subunit 1 gene and partial nicotinamide dehydrogenase subunits 4 gene showed relatively high genetic variation within the species compared with ribosomal DNA markers.

Using ribosomal (18S, ITS1, ITS2, D2-D3 expansion segments of 28S rDNA) and mitochondrial (partial cox1 and nad4) DNA markers in a study of several populations of Xiphinema americanum-group from Europe and Morocco, two cryptic species Xiphinema browni sp. n. (formerly reported as Xiphinema pachtaicum) and Xiphinema penevi sp. n. were revealed. The species are described, illustrated and their phylogenetic relationships discussed. The first species is most similar to Xiphinema parasimile and is a member of Xiphinema simile species complex. The phylogenetic reconstructions inferred from three molecular markers (18S, D2-D3 28S rDNA and cox1) showed that Xiphinema penevi sp. n. is part of Xiphinema pachtaicum-subgroup and is closely related to Xiphinema incertum, Xiphinema pachtaicum, Xiphinema parapachydermum, Xiphinema plesiopachtaicum, Xiphinema astaregiense and Xiphinema pachydermum. Also, a separate “Xiphinema simile-subgroup”, outside the Xiphinema pachtaicum-subgroup and so far consisting only of the parthenogenetic species Xiphinema simile, Xiphinema parasimile, Xiphinema browni sp. n. and probably Xiphinema vallense was formed. New primers for amplification and sequencing of part of the nad4 mitochondrial gene were designed and used.