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.
2010
Sammendrag
Isolates of Colletotrichum sublineolum were collected from different sorghum-producing regions of Ethiopia and divided into five groups based on their geographic origin. The growth rate of 50 isolates showed considerable variation: 1·7?5·8 mm day?1, mean 3·3 mm day?1. However, the isolates displayed little variation in colony colour and colony margin, except for isolates from the north, which were different from the others. Amplified fragment length polymorphism analysis of 102 isolates revealed much greater variations among the different groups. Dice similarity coefficients ranged from 0·32 to 0·96 (mean 0·78). Cluster analysis and principal coordinate analysis revealed a differentiation of the isolates according to their geographic origin, and both methods clearly indicated a genetic separation between the southern, the eastern and the other isolates. Analysis of molecular variance (amova) indicated a high level of genetic variation both among (42%) and within (58%) the C. sublineolum sampling sites in Ethiopia. The amova also indicated a high level of genetic differentiation (FST = 0·42) and limited gene flow (Nm = 0·343). The results of this study confirmed the presence of a highly diverse pathogen, which is in agreement with the existence of diverse host genotypes and widely ranging environmental conditions in sorghum-producing regions of the country. Such diversity should be taken into account in future breeding programmes to achieve an effective and sustainable disease management strategy.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Under pynten på grantreet ligger dype hemmeligheter om betydningen av arv, miljø og vår evne til å tilpasse oss våre omgivelser. Et nypyntet juletre er et av høytidens mange vakre symboler. Nyere forskning knytter grantrærnes overlevelsesevne til det som kalles epigenetikk – selve møteplassen mellom arv og miljø. Epigenetiske effekter gir grantrær, mennesker og andre levende vesener fleksibilitet til å tilpasse seg forandringer i omgivelsene raskere enn hva klassisk genetikk tilsier.
Sammendrag
Under pynten på grantreet ligger dype hemmeligheter om betydningen av arv, miljø og vår evne til å tilpasse oss våre omgivelser.
Sammendrag
Insektene er blant de organismene som reagerer raskest på klimaendringer. De har kort generasjonstid, er svært mobile og utviklingshastigheten deres er direkte påvirket av temperaturen. Dette betyr at utviklingen fra egg til voksent insekt går raskere når temperaturen øker, noe som kan få store praktiske konsekvenser for skogbruket.
Sammendrag
The blue-stain fungus Ceratocystis resinifera colonizes wounds on living Picea spp. and other conifers in Europe and North America. Little is known regarding the pathogenicity of this fungus and consequently, four Norwegian C. resinifera isolates were inoculated on to Norway spruce (Picea abies) using two different techniques. These included single-point inoculations on young trees (two inoculations per tree on 14-year-old trees) and mass-inoculations on older trees (∼200 inoculations per tree on 34-year-old trees). In both experiments, C. resinifera induced minor symptoms that in most cases did not differ significantly from inoculation with sterile agar. The virulent blue-stain fungus C. polonica, which was inoculated for comparative purposes, induced extensive symptoms, causing 83% dead cambium circumference and 82% blue-stained sapwood, and long necrotic lesions in the phloem. The results suggest that C. resinifera is non-pathogenic or only mildly pathogenic to Norway spruce and does not present a threat to these trees.
Forfattere
Tao Zhao Paal Krokene Niklas Björklund Bo Långström Halvor Solheim Erik Christiansen Anna-Karin Borg-KarlsonSammendrag
Constitutive and inducible terpene production is involved in conifer resistance against bark beetles and their associated fungi. In this study 72 Norway spruce (Picea abies) were randomly assigned to methyl jasmonate (MJ) application, inoculation with the bluestain fungus Ceratocystis polonica, or no-treatment control. We investigated terpene levels in the stem bark of the trees before treatment, 30 days and one year after treatment using GC–MS and two-dimensional GC (2D-GC) with a chiral column, and monitored landing and attack rates of the spruce bark beetle, Ips typographus, on the trees by sticky traps and visual inspection. Thirty days after fungal inoculation the absolute amount and relative proportion of (+)-3-carene, sabinene, and terpinolene increased and (+)-α-pinene decreased. Spraying the stems with MJ tended to generally increase the concentration of most major terpenes with minor alteration to their relative proportions, but significant increases were only observed for (−)-β-pinene and (−)-limonene. Fungal inoculation significantly increased the enantiomeric ratio of (−)-α-pinene and (−)-limonene 1 month after treatment, whereas MJ only increased that of (−)-limonene. One year after treatment, both MJ and fungal inoculation increased the concentration of most terpenes relative to undisturbed control trees, with significant changes in (−)-β-pinene, (−)-β-phellandrene and some other compounds. Terpene levels did not change in untreated stem sections after treatment, and chemical induction by MJ and C. polonica thus seemed to be restricted to the treated stem section. The enantiomeric ratio of (−)-α-pinene was significantly higher and the relative proportions of (−)-limonene were significantly lower in trees that were attractive to bark beetles compared to unattractive trees. One month after fungal inoculation, the total amount of diterpenes was significantly higher in putative resistant trees with shorter lesion lengths than in putative susceptible trees with longer lesions. Thus, terpene composition in the stem bark may be related to resistance of Norway spruce against I. typographus and C. polonica.
Sammendrag
The anamorph genus Leptographium Lagerberg and Melin includes species that are typically bark beetleassociated fungi, with teleomorphs in Grosmannia. During a survey of ophiostomatoid fungi in Norway, two unusual species, that fit the broader morphological description of Leptographium, were isolated directly from the rootfeeding beetles, Dryocetes authographus and Hylastes cunicularius, as well as from roots infested by these insects. The first of these could be distinguished from other described species based on a sparse sporulation, black spore drops and chlamydospores in older cultures. This species also produces a Hyalorhinocladiella synanamorph. The second species was characterised by distinctly curved conidia. Based on these unusual morphological characteristics and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium chlamydatum sp. nov. and L. curvisporum sp. nov. are provided.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Hvordan tilpasser trærne seg til klimaendringer? Hva gjør de for å forsvare seg mot sopp- og insektangrep? Hvilken vei vandret grana inn i Norge etter siste istid? Hvordan påviser vi nye sykdommer på trær, eller begynnende råte i trebygninger? Og hvordan kan granas verste fi ende hjelpe oss med å lage framtidens biodrivstoff? Dette er noen av spørsmålene Skog og landskaps forskere stiller seg. I mange tilfeller er moderne bioteknologi en del av løsningen. På Skog og landskap bruker vi ulike bioteknologiske metoder for å løse forskningsoppgaver innen blant annet skoghelse, treteknologi, genetikk og økologi. Denne brosjyren forteller deg mer om våre forskningsaktiviteter knyttet til bioteknologi. Ordet bioteknologi blir ofte brukt synonymt med molekylærbiologi, genteknologi og molekylærgenetikk, og er en integrert del av moderne biologisk forskning. Dyr, planter, sopp eller mikroorganismer som bakterier og virus, eller DNAet (arvestoffet) fra disse, brukes til å produsere nye produkter. Ølbrygging er et tidlig eksempel på bioteknologi, og stiklingsformering av trær og andre nytteplanter er en eldgammel form for kloning. Brosjyre fra Skog og landskap, 3/2010.