Selection for resistance against root pathogens in a pea composite cross

The possibility of improving resistance in pea against the root pathogen Aphanomyces euteiches using composite cross as a breeding and selection method was examined. In order to maintain acceptable agricultural features and high yield 6 out of the 8 parental varieties in the present composite-cross were commercially grown varieties. Populations of the composite cross were grown up to five generations with selection pressure in soil heavily infested with pea root pathogens or without selection pressure on soil free of pea root pathogens. Yield of populations of the F9 and F10 generations of the composite cross grown with selection pressure was on average 35% higher than that of the population obtained without selection pressure as well as the average yield of the 8 parentals of the composite cross, which were of similar magnitude. In healthy soil the yield was overall higher than in the pathogen-infested soil, but yield did not differ between the populations from the composite cross with and without selection pressure, which were also similar to the average yield of the 8 different parentals. Recombinant inbred lines (RILs) randomly selected from the F10 population with selection pressure developed 23% less root rot than the corresponding F10 population without selection pressure, when grown in field soil heavily infested with pea root pathogens. Surprisingly, greenhouse pot experiments with pure cultures of the pea root pathogen A. euteiches resulted in higher root disease, in RILs from populations with selection pressure than from corresponding RILs without selection pressure. Problems related to greenhouse screening for resistance is discussed as well as the possibilities of using composite cross as a method to improve resistance against root diseases in grain legumes

Specificity of soil-borne pathogens on grain legumes

Specificity of soil-borne legume pathogens on pea, lupin and faba bean is currently investigated in fields where grain legumes are intensively cultivated. The study has so far lead to the following conclusions -Legume host-pathogen interactions demonstrate specificity of pathogen populations particularly in pea and lupin. -A. euteiches rot root was specified to pea in Denmark as root rot symptoms and oospores of the pathogen never were observed in roots of faba bean and lupin -F. oxysporum followed by F. solani were most frequently isolated from plant roots in plots highly infested by lupin pathogens -F. avenaceum was most frequently isolated from plant roots in plots highly infested by pea pathogens -Pathogenicity tests showed F. solani followed by F. avenaceum to be the most pathogenic Fusarium species on pea while F. avenaceum was the most destructive pathogen on faba bean. In contrast F. avenaceum was non-pathogenic on lupin

Gulerodens farefulde vej fra marken til forbrugeren

Kølelagring af Lammefjords-gulerødder muligør, at der kan leveres danskproducerede gulerødder i perioden fra november til april. Sidst på lagringssæsonen kan mere ed 50% af rødderne dog være kassable på grund af lagersygdomme. I marken angribes rødderne af forskellige jordboende svampe, der allerede ved høst kan resultere i kassable rødder. I lagerperioden kan tilsyneladende raske gulerøder dog også udvikle sygdomme forårsaget af de mikrosvampe der forkommer naturligt på rødderne. Sår på rodoverfladen fremmer angreb under lagring og desuden reduceres gulerøddernes modstandsdygtighed overfor sygdomme i takt med røddernes aldring. I artiklen beskrives de mest betydende sygdomsfremkaldende organismer (patogener), faktorer der er af betydning for udvikling af lagersygdomme samt muligheder for forbedret lagerkvalitet ved hjælp af biologiske forebyggelsesmetoder

Functional Compost

The aim of the research program Functional Compost is to develop and test compost, which have been enriched with chitin, for plant growth promoting properties and to recognise specific mechanisms. Two types of compost were included in the program: source separated biodegradable municipal solid waste compost (DM = 62 %) and garden and park waste compost (DM = 66 %). Chitin was added in trace amounts during the maturity phase, combined with two levels of trace amounts immediately before adding the compost to the growth medium. The research program includes several parallel experiments. In experiment I, compost (20 vol. %) was added to soil (no plants) and incubated at 15 C for 5 month, under regular determination of microbial respiration and gross and net N mineralization. There was a significant increase in respiration due to chitin enrichment, which could not be explained by the amount of C derived from the chitin, which therefore suggest a priming effect. The N analyses are still being processed in the laboratory, but data are expected to be available at the conference. In experiment II, compost was mixed with sand, put into pots in a climate chamber, and spring barley seeds infected with Fusarium culmorum were sown in the pots. After 3 weeks of growth, the health of the plants was determined, and the chitinase activity in the sand was measured. The health of the plants and the chitinase activity was significantly higher in the treatments receiving municipal waste compared to the treatments receiving garden waste compost. However, there was no clear effect of the chitin enrichment. Additionally, the microbial community structure of the two types of compost, with and without early chitin, was determined by Denaturing Gradient Gel Electrophoresis (DGGE). There was a clear separation between compost types, and with or without early chitin amendment. Experiment III is a regular growth experiment, and is running right now. Compost has been incorporated into soil, put into pots in the greenhouse, and spring barley is grown for 2 month before determination for wet and dry weight and N uptake. Data from experiment III is expected to be available at the conference

Sårbarhet og avmakt? Arbeidsvilkår for norske mediefrilansere i en endringsutsatt bransje

Som en følge av strukturelle og økonomiske endringer i den norske mediebransjen, ser andelen frilansere og midlertidige ansatte ut til å øke. Denne artikkelen undersøker gjennom kvantitative data og ulike maktperspektiver i hvilken grad arbeidsvilkårene til frilansere skaper usikkerhet og sårbarhet for en gruppe som står utenfor det regulerte arbeidslivet. Analysen viser at norske mediefrilansere er høyt utdannet og trives med det faglige innholdet i arbeidet. Samtidig er gjennomsnittsinntekten lav, de mangler økonomiske sikkerhetsnett og sliter med å skille jobb og fritid. Norske mediefrilansere er dermed delvis marginaliserte med tanke på vilkårene de arbeider under, samtidig som de har en relativ høy grad av autonomi og faglig frihet.As a result of structural and economical changes in the Norwegian media industry, the proportion of freelancers and temporary employees appears to be increasing. Through quantitative data and perspectives on power, this article examines to which extent working conditions for freelancers create uncertainty and vulnerability for a group that is outside the standard employment relationship. Norwegian media freelancers are highly educated and value the professional content of their work. At the same time, average income is low, they lack financial safety nets and struggle to separate work and leisure. Norwegian media freelancers are thus partially marginalised in terms of the conditions under which they work, while also having a relatively high degree of autonomy and professional freedom.publishedVersio

Sædskiftesygdomme i lupin, ærter og hestebønne

EU’s generelle ønske om mindre import af sojaprotein og kravet om 100% økologisk fodring vil nødvendiggøre, at andelen af frøbælgplanter i sædskiftet øges. Frøbælgplanter som ært, hestebønne og lupin er oplagte afgrøder, blandt andet på grund af deres høje indhold af værdifulde proteiner og evnen til at fiksere luftens kvælstof. En af den største hindringer for at øge andelen af bælgplanter er de jordbårne patogener, der kan overleve mange år i jorden og derfor udgør en risiko for frugtbarheden af det økologiske dyrkningssystem. For at mindske risikoen for problemer med sædskiftesygdomme, anbefales flere dyrkningsfrie år mellem samme frøbælgplanteart. Aphanomyces rodråd et godt eksempel på en sædskiftesygdom, der kan umuliggøre ærtedyrkning i op til 20 år. En ny dansk undersøgelse med lupin har desuden vist, at bare én sæson med dyrkning af en Fusarium modtagelig lupinsort, kan være tilstrækkeligt til at give udbredt visnesyge i modtagelige sorter i en efterfølgende vækstsæson. Ved inddragelse af flere frøbælgplantearter i sædskiftet er det vigtigt, at undersøge om arterne har fælles sædskiftesygdomme. Lupin, hestebønne og -ærtesorter er i 2 års markforsøg testet på henholdsvis en ærtetræt jord domineret af Aphanomyces rodråd og en lupintræt jord, hvor der tidligere er observeret alvorlige Fusarium-symptomer i lupin. På lupintræt areal havde såvel lupin som hestebønne udbredte rodnekroser, hvorfra der blev isoleret identiske Fusarium arter. Da ærterødderne var symptomfri, tyder det på, at Fusarium patogener fra lupin ikke angriber ærterødder. På det ærtetrætte areal var ærterødderne ødelagt, primært af Aphanomyces, hvorimod lupinrødderne var uden symptomer. Hestebønnerne havde rodnekroser i det ene år, og der blev isoleret Fusarium spp. identiske med arter isoleret fra ærterødder. Hidtil er der ikke fundet Aphanomyces i hverken hestebønne eller lupin. Patogenicitet af Fusarier fra ært og hestebønnerødder fra ærtetræt jord er foreløbig kun testet på de to arter. Resultaterne antyder, at F. oxysporum og F. avenaceum kan spille en betydende rolle i komplekset af rodpatogene svampe på både ært og hestebønne. Der arbejdes nu videre med at belyse identiske svampenes værtplanteregister og patogenecitet på all tre arter af frøbælgplanter

The end-state comfort effect in 3- to 8-year-old children in two object manipulation tasks

The aim of the study was to compare 3- to 8-year-old children’s propensity to anticipate a comfortable hand posture at the end of a grasping movement (end-state comfort effect) between two different object manipulation tasks, the bar-transport task, and the overturned-glass task. In the bar-transport task, participants were asked to insert a vertically positioned bar into a small opening of a box. In the overturned-glass task, participants were asked to put an overturned-glass right-side-up on a coaster. Half of the participants experienced action effects (lights) as a consequence of their movements (AE groups), while the other half of the participants did not (No-AE groups). While there was no difference between the AE and No-AE groups, end-state comfort performance differed across age as well as between tasks. Results revealed a significant increase in end-state comfort performance in the bar-transport task from 13% in the 3-year-olds to 94% in the 8-year-olds. Interestingly, the number of children grasping the bar according to end-state comfort doubled from 3 to 4 years and from 4 to 5 years of age. In the overturned-glass task an increase in end-state comfort performance from already 63% in the 3-year-olds to 100% in the 8-year-olds was significant as well. When comparing end-state comfort performance across tasks, results showed that 3- and 4-year-old children were better at manipulating the glass as compared to manipulating the bar, most probably, because children are more familiar with manipulating glasses. Together, these results suggest that preschool years are an important period for the development of motor planning in which the familiarity with the object involved in the task plays a significant role in children’s ability to plan their movements according to end-state comfort