208 research outputs found

    Effect of moderate and severe drought stress on the pre-anthesis development and yield formation of oats

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    Greenhouse experiments were conducted at the University of Helsinki, Department of Crop Husbandry in 1989 and 1990 to provide information on the effects of drought stress on the developmental rate of the panicle, formation and abortion of florets, and formation of yield components in two oat cultivars, both adapted to the northern marginal growing conditions. Moderate water deficit and severe drought stress did not affect the developmental rate of the panicle, but the pre-anthesis and post-anthesis architecture changed considerably; leaves unrolled later, the number of green leaves was lower, the internodes lengthened less, and the inflorescence was shorter as a consequence of water deficit. Drought stress decreased the number of fertile florets in the panicle significantly, in the lower clusters of branches in particular. In the cultivar “Puhti”, 57 % of the fertile florets aborted as a consequence of moderate drought stress and 89 % as a result of severe drought stress when compared to well-watered individuals, while in “Virma”, a cultivar of significantly higher yield potential, 80 °lo and 90 % of the fertile florets wilted, respectively. In addition, water deficit caused considerable losses in all the morphological characteristics measured. Further implications of these results for yield formation are discussed

    Yield reduction caused by a soil-borne disease of naked, dwarf, and conventional oat in Finland

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    A severe disease occurred in the field plots of naked (cv. Salomon), dwarf (cv. Pal), and conventional oat (cvs. Jalostettu maatiainen and Salo) at the Viikki Experimental Farm of the University of Helsinki, Finland, in 1994 and 1995. Symptoms were expressed as grayish-brown necrotic areas on the lower leaves which killed plants from the seedling to heading stage, the effect being cultivar dependent. The proportion of plants killed contributed to the yield losses. The infection also resulted in less grains per panicle and lower weight of both panicle and vegetative above-ground biomass. From a total of 57 fungal isolates obtained from infected leaves, Fusarium culmorum (W.G.Sm.) Sacc. and F. sambucinum Fuck, dominated and subsequently caused infection (particularly foot and root rot) in oat in laboratory tests. These two Fusarium spp. were considered to be the primary causal agents of the symptoms observed in the field, although other pathogens may have been present. The disease was probably soil-borne. The results of this study suggested that the unusually dry and warm weather during late June and in July was the principal factor behind the severe disease outbreak

    Sää- ja ilmastoriskit Suomessa - Kansallinen arvio

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    Tähän raporttiin on koottu ajantasainen arvio sään ja ilmaston aiheuttamista riskeistä eri toimialoille Suomessa. Arviossa otettiin huomioon sekä muuttuvan ilmaston että yhteiskunnallisen kehityksen vaikutus riskin muodostumiseen nykyhetkessä ja tulevaisuudessa. Sää- ja ilmastoriskejä pyrittiin hahmottamaan vaaratekijän (riskiä aiheuttava sääilmiö), altistumisen (riskin kohteen sijainti) ja haavoittuvuuden (riskin kohteen ominaisuudet) yhdistelmänä. Sääilmiöt aiheuttavat Suomessa riskejä jo nykyilmastossa. Muun muassa rajuilmat, helleaallot ja rankkasateet aiheuttavat taloudellisia ja terveydellisiä vaikutuksia sekä yleistä haittaa. Tulevaisuudessa riskit muuttuvat ilmastonmuutoksen muuttaessa haitallisia sääilmiöitä. Ilmastonmuutos tuo vähitellen kasvavia riskejä erityisesti ekosysteemeille ja infrastruktuurille. Muualla maailmalla tapahtuvat ilmastonmuutoksen vaikutukset voivat heijastua epäsuorasti Suomeen globaalien tavara-, energia-, raha- ja ihmisvirtojen kautta. Näiden riskien systemaattinen arviointi on vasta aloitettu. Raportin tavoitteena on tukea yhteiskunnan riskeihin varautumista ja ilmastonmuutokseen sopeutumista eri hallinnon tasoilla ja toimialoilla. Arvio perustuu pääosin kirjallisuudesta löytyviin tutkimuksiin ja selvityksiin sekä asiantuntija-arvioihin. Työ tehtiin “Sää- ja ilmastoriskien arviointi ja toimintamallit” (SIETO)- hankkeessa vuosina 2017–2018

    GWAS of Barley Phenotypes Established Under Future Climate Conditions of Elevated Temperature, CO2, O3 and Elevated Temperature and CO2 Combined

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    AbstractClimate change is likely to decrease crop yields worldwide. Developing climate resilient cultivars is one way to combat this production scarcity, however, little is known of crop response to future climate conditions and in particular the variability within crops.In Scandinavia, barley is widely cultivated, but yields have stagnated since the start of this century. In this study we cultivated 138 spring barley accessions in a climate phytotron under four treatments mimicking forecasted levels of temperature, carbon dioxide concentration ([CO2]) and ozone ([O3]) at the end of the 21st century1. The ambient control had 19/12°C (day/night) and [CO2] at 385ppm. Three single-factor treatments had elevated temperature +5°C day/night, [CO2] at 700ppm or [O3] at 120 ppb, and in a two-factor treatment the combination of elevated temperature and [CO2] was applied.Treatment effects were assessed on grain yield, grain protein concentration, grain protein harvested, number of grains, number of ears, aboveground vegetative biomass and harvest index. In addition, stability of the production was calculated over the applied treatments for the assessed parameters.In the climate scenario of elevated temperature and [CO2] the grain yield of barley decreased 29% and harvested grain protein declined 22%. Vast variation was identified among the individual barley accessions, which should be exploited by plant breeders in the development of climate resilient cultivars.A genome-wide association study (GWAS) of recorded phenotypes and 3967 SNP-markers identified 60 marker-trait associations (-logp>2.95)2. Markers were found associated with grain yield under all three single factor treatments temperature, [CO2] and [O3], as well as with stability over treatments.To our knowledge, this is the first study that evaluates numerous barley accessions under future climate conditions and identifies candidate markers for abiotic stress tolerance - markers that could be used in the development of cultivars to secure future primary production

    Genetic analysis of the naked trait in panicles of hexaploid oat

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    The aim of this study was to estimate the number of genes that control the naked (hull-less) trait and the mode of expression of this characteristic in panicles of hexaploid white oat. Parents and the segregating population (in the F2 and F3 generations) were evaluated in regard to the presence and distribution of naked grains in panicles of individual oat plants. For each plant, a drawing of the main panicle was developed. From the drawings obtained in the progenies of the F2 population, six distinct phenotypic classes were produced. The expected phenotypic proportion of 3:9:4 (naked:segregating:hulled) was that which best fit by the Chi-square test. In the F3 generation, the results showed agreement with the hypothesis observed in the F2 generation. The naked trait in oat is passed on by two genes and the greatest expression of this trait occurs in the upper third of the panicles. Expression of this trait in oats is not complete, even in homozygous genotypes
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