| 1. |
- Ahmed, Mohammed, et al.
(författare)
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A draft transcriptome of a parasite Neocamacolaimus parasiticus (Camacolaimidae, Plectida)
- 2021
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Ingår i: Journal of nematology. - : Walter de Gruyter GmbH. - 0022-300X .- 2640-396X. ; 53
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Tidskriftsartikel (refereegranskat)abstract
- Camacolaimidae is a clade of nematodes that include both freeliving epistrate feeding forms and parasites of marine protozoans and invertebrates. Neocamacolaimus parasiticus is a parasite of marine polychaete worms. Given its phylogenetic affinities to free-living species, Neocamacolaimus can be a reference for research of the origin of parasitism in an aquatic environment. Here, we present a draft transcriptome obtained from a single post-parasitic juvenile individual of this species. The final assembly consists of 19,180 protein coding sequences (including isoforms) with the following BUSCO scores for Nematoda: 65.38% complete, 9.06% partial, and 25.56% missing, and for Metazoa: 79.45% complete, 3.17% partial, and 17.38% missing.
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| 2. |
- Ahrén, Dag, et al.
(författare)
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Evolution of parasitism in nematode-trapping fungi
- 2003
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Ingår i: Journal of Nematology. - 0022-300X. ; 35:2, s. 194-197
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Konferensbidrag (refereegranskat)abstract
- We are studying the evolution of parasitism in a group of soil-living ascomycetes that can grow as saprophytes as well as parasites by forming special morphological structures called traps. Analyses of 18S ribosomal DNA sequences have shown that these fungi form a monophyletic and isolated clade among the ascomycetes. The phylogenetic patterns within this clade are concordant with the morphology of the traps and separate species having adhesive traps (nets, knobs, and branches) from those having constricting rings. This suggests that these nematode-trapping fungi have a common ancestor, and that the ability to capture nematodes has been an important trait for further speciation and diversification within the clade. To obtain information on the genomic basis for this pattern, we recently started a large-scale sequencing project of the nematode-trapping fungus Monacrosporium haptotylum. This will allow the identification of genes uniquely expressed during the development of traps, and elucidate the molecular evolution Of Such genes within the nematode-trapping fungi clade.
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| 3. |
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| 4. |
- Viketoft, Maria, et al.
(författare)
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Synergistic interaction between plant-feeding nematodes and the fungus rhizoctonia solani in potato
- 2014
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Ingår i: Journal of Nematology. - 0022-300X. ; 46, s. 252-253
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Konferensbidrag (refereegranskat)abstract
- Stem canker caused by the pathogenic fungus Rhizoctonia solani is a major problem for potato cultivation throughout Sweden, especially as it leads to great economic losses. Advisors and growers have developed a theory that there is a correlation between the severity of stem canker and plant-feeding nematodes, as high occurrences of stubby-root and rootlesion nematodes were found in potato fields with high incidence of stem canker. The aim of this project was to investigate any interactions between these nematodes and the fungus under controlled conditions. In the first experiment, pregerminated minitubers (cv King Edward) were planted in pots with sterilised sand and placed in a climate chamber at conditions corresponding to a Swedish spring. Fungal mycelium and/or nematodes (Pratylenchus penetrans) were added to the pots in various combinations. The pots were harvested ten weeks after inoculation and the parameters measured were fresh and dry weight of stems, stolons, tubers and roots, as well as the gradation of the damage caused by the nematodes and the fungus of the different plant parts. The nematodes produced feeding symptoms on stems, tubers, stolons and roots, but the roots also became brownish to different degrees. The fungus caused stem canker of different severity on the stems, burned off stolons and produced sclerotia on the roots and on the majority of the tubers. We found a synergistic effect between R. solani and P. penetrans, as the tuber yield decreased significantly when both nematodes and fungus were present in the pots.
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| 5. |
- Wallenhammar, Ann-Charlotte
(författare)
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Development of a decision support system for managing Heterodera schahtii in sugar beet production
- 2019
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Ingår i: Journal of Nematology. - : Walter de Gruyter GmbH. - 0022-300X .- 2640-396X. ; 51
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Tidskriftsartikel (refereegranskat)abstract
- A decision support system, SBN-Watch, was developed to demonstrate the influence of crop rotation and the choice of sugar beets (Beta vulgaris) varieties on the sugar beet cyst nematode Heterodera schachtii Schmidt (SBN) population and sugar beets yield. The database in SBN-Watch consists of a varietal unit with five sugar beet varieties representing the three categories "Standard," "Tolerant," and "semi-tolerant." Data of minimal yield (m), tolerance limit (T), and population dynamic parameters were obtained from published commercial field trials conducted in Sweden and Denmark in 2011. Additionally, a sanitation intercrop unit with different resistant classes of white mustard (Sinapsis arvensis) and oil seed radish (Raphanus sativus) was included. The relationship between initial population (Pi) and sugar yield as well as SBN final population in soil (Pf) was calculated by two Seinhorst equations. Few data inputs are required to be entered by the user in SBN-Watch, mainly the initial population (Pi), expected sugar price and exchange rate of (sic) to SEK. The calculated reproduction factor (Rf) values using SBN-Watch corresponded well with varietal characteristics, where the standard variety Mixer had the highest (RI) values. The influence of the initial SBN population on the calculated sugar yield (tonnes ha(-1)) was generally small at Pi < 2.
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| 6. |
- Walter, Abigail, et al.
(författare)
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GENE TRANSCRIPTION CHANGES DURING COMPATIBLE AND INCOMPATIBLE INFECTIONS OF POTATO BY GLOBODERA ROSTOCHIENSIS
- 2014
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Ingår i: Journal of Nematology. - 0022-300X. ; 46, s. 253-253
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The golden potato cyst nematode,Globodera rostochiensis, is one of the most important pests of potato in Sweden. Several pathotypes of the nematode exist, and they may be controlled by one of several sources of single-gene resistance in potato. Here we report that SW93-1015, a breeding line from the potato breeding program at SLU Alnarp, has phenotypic resistance to the Ro1/4 pathotype ofG. rostochiensis. Reproduction ofG. rostochiensispathotype Ro1/4 on SW93-1015 is approximately 5% of reproduction on the susceptible cultivar Desiree. To further investigate the interaction between potato cyst nematodes and susceptible and resistant host plants, changes in gene transcription were monitored just after root penetration and during syncytium formation in Desiree and SW93-1015 potato plants infected with Ro1/4G. rostochiensis.RNA expression in root tissue was analysed on a microarray at 0, 8, and 48 h post-infection, corresponding to pre-infection, root penetration, and early syncytium formation. Changes in gene transcription over the process of infection in susceptible and resistant genotypes are discussed. The resistance will be further investigated using a crossing population if Desiree and SW93-1015.
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