Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2009
Forfattere
Ricardo Holgado Stig Andersson Janet Rowe Ian Clark Christer MagnussonSammendrag
Norwegian cereal cyst nematode populations were studied by biochemical, molecular, morphological and bio test techniques. H. avenae occurred in the pathotypes, Ha11, Ha12, and H. avenae Våxtorp. H. filipjevi was recorded as pathotype West. H. avenae (Ha 11) and H. filipjevi West were the most common species. Thirty barley, 23 oat and 6 of summer wheat cultivars on the Norwegian market were tested for their resistance against H. avenae (Ha11), H. avenae Våxtorp and H. filipjevi West. Resistance against Ha11 was found in 5 barley, 3 oat and in 1 wheat cultivar. Resistance against H. avenae Våxtorp was not present in barley, but 4 oat and 1 wheat cultivar were resistant. For H. filipjevi West resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. A management system based on careful nematode identification and knowledge on resistance of cultivars were set in operation in the county of Vestfold. As a result farmers have improved average yields by 1000 kg /ha. By implementing this program in full the county of Vestfold could make an annual gain of 800 000 €. In perspective of increasing damage from CCN world-wide the correct identification of species and the recognition of their genetic variability is instrumental for successful control.
Forfattere
Ricardo HolgadoSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo Holgado Stig Andersson Janet Rowe Ian Clark Christer MagnussonSammendrag
Cereal cyst nematodes (CCN), Heterodera spp. are well-known world-wide as parasites of cereals. In Scandinavia H. avenae is the most common species and occurs in the pathotypes, Ha11 and Ha12, and the additional pathotypes H. avenae-Knislinge, H. avenae-Ringsåsen and H. avenae-Våxtorp. H. filipjevi, which occurs in the two pathotypes, "East" and "West" is less common than H. avenae. For several years it has been known that resistance to cereal cyst nematodes may be found in some commercial cultivars, although no conscious breeding for resistance has been attempted. In 2004 and 2005 a majority of cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West" The test program included 30 cultivars of barley, 23 cultivars of oats and 6 cultivars of summer wheat. Resistance against Ha11 was found in 5 barley, 3 oat cultivars and in 1 wheat cultivar. Resistance against H. avenae pathotype "Våxtorp" was not present in barley, but 4 oat cultivars and 1 wheat cultivar were resistant. For H. filipjevi "West" resistance was not detected in wheat, but in 6 barley and 13 oat cultivars. Obviously the variability in CCN is larger than generally anticipated. In Norway management systems based on careful nematode identification and good knowledge of suitable resistant cultivars are in operation. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields of in average 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 € annually. In perspective of increasing damage from CCN world-wide the recognition of its genetic variability is instrumental for successful control.
Forfattere
Nadeem Yaqoob Carl Gunnar Fossdal Jan Karlsson Benedicte Riber Albrectsen Halvor SolheimSammendrag
Due to the great economic losses caused by the root and butt-rot pathogen Heterobasidion annosum, development of efficient control measures is warranted. H. annosum a necrotroph colonize the Norway spruce from inside and is responsible for 100s of millions of Euros losses annually. Considerable clonal variation has been recorded for Norway spruce in resistance towards H. annosum, but the defence mechanisms contributing to host resistance against both necrotrophic and biotrophic fungi remain poorly understood. The recent genome sequencing of Populus has made the genus a model to facilitate tree genetics. Genome-wide transcript profiling of Populus tremula upon pathogen attack will now be used, and homologues of Norway spruce genes to defence genes up-regulated in Populus will be identified. Two aspen clones (23 and 72) from the SwAsp collection (Luquez 2007) were used in the present study. Plants were propagated from tissue culture and kept in greenhouse under un-manipulated conditions. To study the host defence mechanisms, the rust (Melampsora magnusiana Wagner) and a bluestain fungus were used as a biotrophic and necrotrophic fungus respectively. Melampsora spores solution was applied to the underside of the leaf. To control for sectoriality six leaves were infected on each plant. To ensure high humidity and avoid cross contamination, plastic bags were wrapped around infected leaves. Leaves above infected leaves (10, 9, and 8) were harvested respectively 1, 3 and 14 days after inoculation. Initial results from microarray data indicate a clear separation between two Aspen clone (23 and 72) lines. For line 23 the response to biotroph and necrotroph seems to be similar. Whereas the response for line 72 is divergent for the treatments as they go in opposite direction. The controls show that there is an initial difference in the 2 lines (controls are separated). What are the genes that make biotrohic and necrotrophic treatment of 72 look so different will be worked out from microarray data. Differential expression of defense genes in biotrohic and necrotrophic treatment will be verified further with quantitative real time PCR. Chemical analysis of Aspen leaves gave less phenolic compounds as plants were kept in greenhouse. HPLC will be carried out after reaching some conclusion from microarray data analysis.
Forfattere
Ricardo Holgado John Ingar Øverland Bonsak HammeraasSammendrag
To arter av rotgallnematoder, Meloidogyne hapla og M. ardenensis, er vanlige å finne på friland i Norge. Sommeren 2008 ble det funnet en tredje art, M. naasi, på skadet hvete i Vestfold. Funnene er de første av denne rotgallnematoden i Norge og Skandinavia. Den er også funnet på flere ugras. M. naasi er en viktig skadegjører på bygg i tempererte områder.
Forfattere
Trond HofsvangSammendrag
Hagen er full av insekter. Noen skader plantene, andre er nyttedyr som reduserer bestanden av skadeinsekter. Men hva er hva? Her er en oversikt over noen vanlige nytte- og skadeinsekter.
Forfattere
Ricardo HolgadoSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
The Altiplano is one of the most elevated areas populated in the world. At 3 500 - 4 000 m, low temperature, and other climatic conditions impose severe limitation for vegetable production. The average temperature levels and the daily amplitudes is a function of altitude, so vegetables are mainly produced in rustic greenhouses. NGOs in the Andean region have recommended cultivation of vegetables for consume and commercialization to enhance the well being of farmers. Plant parasitic nematodes or poor management have limited the vegetable production in rustic greenhouse. The Catholic University of Bolivia has a network of rural campuses "Unidades Académicas Campesinas" (UAC) for academic and practical teaching. Bioforsk has been involved in developing and strengthening the scientific basis in Plant Nematology in UAC-Tihauanaco. Farmers in Tiahuanaco experienced decreasing vegetable yields. In 1999 soil and plant samples from potato and other Andean crops were collected from greenhouses. All samples contained plant-parasitic nematodes. Twenty-one genera of plant-parasitic nematodes were found. The most frequent were potato cyst nematodes Globodera rostochiensis and the false root-knot nematode Nacobbus sp. (54 %), followed by lesion nematodes Pratylenchus spp. spiral Helicotylenchus sp. and Tylenchus sensu lato (41 %), ring nematodes Criconemella sp. (34 %), stunt nematodes Tylenchorhynchus spp. (29 %) and root-knot nematodes Meloidogyne sp. (19 %). The study indicated that plant-parasitic nematodes have a large impact on vegetable production. The knowledge of nematode species are of fundamental importance in the design of efficient management strategies, that would allow farmers to keep nematode population densities at levels below the threshold of economic damage. Management with crop rotation and the use of cultivars with resistance are important control measures, but require detailed information on the occurrence and density of nematode species.
Forfattere
Maria HerreroSammendrag
Det er ikke registrert sammendrag
Sammendrag
Peruskjellfrø tilhører den biologiske gruppen sommerettårige ugras. Planten har en greinet pålerot, og kan bli 20-80 cm høy. Stengelen er opprett, greinet, av og til med tre greiner fra samme bladfeste, og korthåret i toppen. Bladene er motsatte og rundtagget. De nederste er kortstilket, eggformet og tilspisset, de øvre er omtrent sittende, avlange og lansettformet. Planten har mange små prestekrageliknende korger. Frukten er en nøtt med fnokk, her representert som frynsete eller helt oppflisete skjell, og som i tørrvær brer seg ut som en fallskjerm, slik at fruktene fyker av gårde med vinden. Forekommer i åpen åker, på avfallsplasser og veikanter. Liker best leirjord, synes å tilpasse seg mange typer jordarter og fuktighetsforhold. Er varmekjær og ømfintlig for frost. Opptrer som ugras i alle slags åkerkulturer, og spesielt i byer, hage og gartnerier. Mindre brysom i Skandinavia. Stammer opprinnelig fra Peru i Sør-Amerika, og ble introdusert til botanisk hage i Madrid i 1790-årene. Kom til Norge i 1830. Kan bekjempes som andre sommerettårige ugrasarter.