Populations of parasitic nematodes colonizing Jerusalem artichoke (Helianthus tuberosus L.)

The populations of parasitic nematodes colonizing the rhizosphere of Helianthus tuberosus L. grown in Polish plantations were studied in the summer of 2016 and the spring of 2017. A total of 35 nematode species were identified: Paratrichodorus pachydermus, Trichodorus cylindricus, T. viruliferus, Longidorus attenuatus, L. elongatus, L. leptocephalus, Criconema annuliferum, Criconemoides informis, Mesocriconema rusticum, M. solivagum, M. xenoplax, Paratylenchus nanus, P. neoamblycephalus, P. projectus, Bitylenchus dubius, B. maximus, Merlinius brevidens, M. nothus, Scutylenchus quadrifer, S. tartuensis, Helicotylenchus digonicus, H. pseudorobustus, H. vulgaris, Rotylenchus pumilus, R. robustus, Pratylenchus crenatus, P. fallax, P. neglectus, Hirschmanniella gracilis, Aphelenchoides fragariae, Aphelenchus avenae, A. eremitus, Ditylenchus dipsaci, and D. medicaginis. Aphelenchoides fragariae and Ditylenchus dipsaci could be foliar pathogens of H. tuberosus L. This is the first study to demonstrate the presence of A. fragariae on the leaves of the Jerusalem artichoke in Poland. The frequencies of occurrence and population densities of the 35 nematode species were determined

Plant parasitic nematodes in the soil and roots of Winter wheat grown in crop rotation and long – term monoculture

The species structure of plant parasitic nematode populations from the rhizosphere of winter wheat grown with crop rotation or in 48-year-old monoculture was analyzed and compared. Dominating species: Bitylenchus dubius, Merlinius microdorus, Paratylenchus neglectus and Heterodera avenae, in monoculture plots, had higher populations than in crop rotation plots. Heterodera avenae eggs and larvae were infected by pathogenic fungi in 68% of the monoculture crops (vs. 65–66% of the cysts from crop rotation), 12–20% of Paratylenchus sp. specimens were colonized by bacteria, mainly by Bacillus penetrans. This study shows nematological changes occurring in long-term wheat breeding, thus providing additional information necessary to fight dangerous viral vectors of the examined cereal