Specimens of the knapweed nematode Subanguina picridis (Kirjanova) Brzeski obtained from different host plants were highly variable in measurement and structure. This variability refutes the validity of six Subanguina species attacking plants in the Asteraceae.

A Russian knapweed (Acroptilon repens) shoot culture system, initiated from shoot tip culture, was used to generate a source of host plant tissue for the rearing of the nematode Subanguina picridis, a biocontrol agent for Russian knapweed. Young shoots growing on solid B5G medium in petri dishes developed galls on leaves, petioles, and shoot tips 7 days after release of 50 nematodes onto the su...

The host range of the knapweed nematode, Subanguina picridis (Kirjanova) Brzeski, under controlled environmental conditions was extended to include, in addition to Russian knapweed, Acroptilon repens (L.) DC., plant species within the Centaureinae, and Carduinae subtribes of the Cynareae tribe of the Asteraceae family. Examination of host response to nematode infection revealed that Russian kna...

several soil samples were taken from western parts of iran. one of the samples col-lected from the rhizosphere of nectarine trees (prunus persica l.) in moghan, ardabil province, contained aprutides guidettii. the species subanguina picridis was recovered from leaf gall of serratula latifolia boiss (asteraceae) in the vicinity of mashhad, khorasan province. although this species showed remarkab...

The knapweed nematode, Subanguina picridis, forms galls on the leaves, stems, and root collar of Russian knapweed, Acroptilon repens. After being revived from a dormant, cryptobiotic state, second-stage juveniles required at least 1 month in a free-living state before becoming infective. Galls were induced on relatively slow-growing host plants that retained their apical meristems at or near th...

The influence of temperature, shoot age, and medium on gall induction by Subanguina picridis on Russian knapweed (Acroptilon repens) was examined in vitro. The optimal temperature for gall formation was 20 C. Gall induction was delayed as the temperature decreased, and decreased as shoot age increased. Bud primordia (0-day-old shoots and 5-day-old shoots) with an average length of 4.2 mm and 7....

Phylogenies were inferred from nearly complete small subunit (SSU) 18S rDNA sequences of 12 species of Meloidogyne and 4 outgroup taxa (Globodera pallida, Nacobbus abberans, Subanguina radicicola, and Zygotylenchus guevarai). Alignments were generated manually from a secondary structure model, and computationally using ClustalX and Treealign. Trees were constructed using distance, parsimony, an...

Goto and Gibler (5) r e p o r t e d that nematodes in leaf galls on Calamagrostis canadensis (Michx.) Beauv. near St. Paul, Minnesota, resembled Anguillulina graminophila [= Subanguina graminophila (T. Goodey, 1933) Brzeski, 1981]. Wu (10) descr ibed Anguina calamagrostis Wu, 1967, later renamed Subanguina calamagrostis (Wu, 1967) Brzeski, 1981 (3), as occur r ing on C. canadensis in On ta r io...