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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.

2011

Sammendrag

Vossalam, Lofotlam og Lyngenlam – kortreist lammekjøtt fra utmarksbeite markedsføres som uovertruffent. Men smaker virkelig nisjelammekjøttet best? Norsk institutt for skog og landskap har kartlagt utmarksbeiter landet rundt. Det er store lokale og regionale forskjeller i mengde og sammensetning av gunstige beiteplanter. Lyngen kommune i Troms har utmarksbeiter av høy kvalitet. Utmarka er en svært verdifull ressurs der. Med 12.000 sauer på beite hvert år har den en kroneverdi på over tre millioner kroner, dersom samme fôrmengde skulle produseres som grovfôr på innmark. For hele landet kan det være snakk om én milliard kroner.

Sammendrag

Vi har nylig sett eksempler på alvorlige sykdommer og dødsfall i Tyskland som per dato antas skyldes forurenset vann som er benyttet til vanning av enkelte grønnsaker. Visse typer tarmbakterier i varmblodige dyr og mennesker kan være årsak til disse og andre sykdommer. Det er generelt økende fokus på å overvåke mat, drikkevann, badevann og vanningsvann for å unngå alvorlige sykdommer. Det er viktig å bruke gode indikatororganismer i slik overvåkning. Vårt inntrykk er at det er en viss mangel på kunnskap om grupperinger innen koliforme bakterier og hva analysedata kan fortelle om forurensningsrisiko. Artikkelen gir en kort innføring i dette tema og kan også være interessant for alle som ser spøkelser når E.coli omtales i media.

Sammendrag

Nematodes, commonly known as round worms, are the most common multicellular animals on planet Earth. After 1000 million years of evolution members of the phylum Nematoda have a high bionomic diversity. As habitants of the soil and rhizosphere nematodes are involved en energy fluxes, and affect carbon and nutrient cycles. As plant parasites, either alone or in synergism with other pathogens, nematodes are responsible for plant disease complexes and major crop losses. A growth depression in a field of potato (Solanum tuberosum) cv. Saturna [resistant to pathotype Ro1 of potato cyst nematode (PCN) Globodera rostochiensis], suggestive of potato cyst nematode damage, was detected in Grue, eastern Norway. Analyses of soil samples did not detect PCN, but demonstrated the occurrence of a large number of lesion nematodes Pratylenchus penetrans .Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium Streptomyces scabies. Potato yield was reduced by 50% in the affected area of the field. Transect-sampling showed plant growth to be negatively correlated with densities of P. penetrans and suggested a damage threshold of potato to the nematode of 100 specimens per250 g of soil. Common scab (Streptomyces scabies) occurred frequently in the affected area. P. penetrans was present in roots, underground stems, stolons and tubers. Tubers from the depressed part of the field had severe symptoms similar to those caused by the common scab bacterium. In tubers, nematodes were detected inside cross-lesions typical symptoms of common scab, and occurred also in the outermost 0.5 mm tissue associated with such lesions. In pots with sterile sand, micro-tubers of potato cv. Saturna, produced from meristems, were grown in a green-house infected with, P. penetrans, S. scabies, and a combination of P. penetrans and, S. scabies. P. penetrans alone induced tuber lesions similar to those of common scab. Also, the combined inoculation of the bacterium and the nematode seemed to enhance symptom expression. Similar scab symptoms, in connection with lesion nematode infections, have been observed on potato tubers cv. Oleva, which also is relatively tolerant to common scab. Symptomatic tubers cv. Saturna first stored at 4o C for 20 weeks were transferred to pots with sterile sand and grown for 3 months in the green-house. In these cultures P. penetrans was first detected in soil 8 weeks after planting. Examination at harvest of soil, roots, stolons, tubers demonstrated symptoms typical of P. penetrans. Interestingly, P. penetrans survives storage of potatoes, from which new infections may develop. Hence, potato tubers do appear to be an important means for the spread of P. penetrans to new areas. The fact that the symptoms induced by this nematode may be mistaken for symptoms of common scab suggests that the frequency of S. scabies might have been overestimated in regular surveys. Infections by P. penetrans have important implications for scab control. This pertains in particular to recommended maintenance of high soil moisture at and during 4-9 weeks after tuber set. If symptoms are related to nematode infection rather than to the scab bacterium, this recommendation would allow for a rapid build-up of lesion nematodes resulting in a decrease in both yield and marketability of the tubers. Further studies are needed to investigate the extent of this problem.