Forage legumes for future dry climates: Lower relative biomass losses of minor forage legumes compared to Trifolium repens under conditions of periodic drought stress     

Martin Komainda  Kai Küchenmeister  Frank Küchenmeister  Laura Breitsameter  Nicole Wrage‐Mnnig  Manfred Kayser  Johannes Isselstein 《Journal of Agronomy and Crop Science》2019,205(5):460-469

Dairy livestock production systems rely on high‐quality forage legumes, which are widely present in grassland swards all over Europe. A future climatic scenario with higher average annual temperatures and lower precipitation is expected to affect grassland productivity in general and the productivity of the most important forage legume species Trifolium repens in particular. One way to cope with such constraints is the adoption of currently underutilized minor legume species with a higher tolerance towards drought stress. Therefore, the present study investigated legume species with lower moisture requirements than T. repens, these are Lotus corniculatus, Medicago falcata, Medicago lupulina and Onobrychis viciifolia in comparison with T. repens. Legumes were grown in containers as monocultures in a roofed open‐sided greenhouse under conditions of optimal water supply or periodic drought stress. Generally, drought stress decreased the biomass production, but species differed in their reaction. Particularly, M. lupulina and L. corniculatus had lower relative biomass losses (?26%) compared to T. repens (?43%, as averaged over drought stress periods). However, in overall biomass production T. repens still was at one level with M. lupulina and L. corniculatus under drought stress. This was related to high stomata control as indicated by the intrinsic water‐use efficiency. We conclude that there are promising future options of forage legumes as alternatives to T. repens.  相似文献   

Abscisic acid response to water status in Dactylis glomerata differs with expression of summer dormancy     

Mark R. Norton  Lisa Xian  Jesse N. Kalic  Trijntje Hughes  Frank Gubler 《Journal of Agronomy and Crop Science》2020,206(5):607-618

Summer dormancy confers superior drought survival in cool-season perennial grasses and is likely to be of increasing importance as climate change proceeds although relatively little is known about this trait. This paper explores the relationship between the level of abscisic acid (ABA), the expression of summer dormancy and the onset and relief of water deficit in cool-season perennial grasses. Three cultivars of Dactylis glomerata L. (cocksfoot) known to differ in expression of summer dormancy were grown in the field over summer and in the glasshouse over winter under water deficit or full irrigation. Hydration and osmotic potentials of basal tissues were measured to assess the level of water deficit, and endogenous ABA was determined in the tissues by monoclonal immunoassay analysis. In a winter trial, higher contents of ABA were present when plant water deficits became greater so that there were no differences between the cultivars in the concentrations of ABA observed. In a summer trial a short period of waterlogging caused water status to increase in all cultivars, although in the maritime cultivar Oasis this was also associated with a rise in ABA contents. In contrast, in the summer-dormant cultivar Kasbah, only low ABA concentrations were observed throughout the entire period whether waterlogged or in drying soil. Heightened ABA levels are not induced by water deficit when summer dormancy is expressed in Dactylis glomerata. This contrasted with those cultivars unable to express summer dormancy where particularly in early summer severe water deficit was associated with heightened ABA levels.  相似文献   

Soil carbon improvement under long‐term (36 years) no‐till sorghum production in a sub‐tropical environment     

Prabhu Govindasamy  Rui Liu  Tony Provin  Nithya Rajan  Frank Hons  Jake Mowrer  Muthukumar Bagavathiannan 《Soil Use and Management》2021,37(1):37-48

Soil organic matter (SOM) is considered an important indicator of soil quality, which can be impacted by crop production practices such as tillage. In this study, two long‐term tillage regimes (conventional tillage [CT] and no tillage [NT], conducted for 36 years) were compared in continuous sorghum production in a sub‐tropical environment in southeast Texas. The positive effects of long‐term NT practice were more conspicuous at the soil surface compared with the deeper soil profiles. The SOC was greater (1.5 t C ha^?1 greater) in the NT system compared with the CT system. Results from an incubation study indicate that the rate of C‐min at 0–5 cm soil depth was significantly greater (164 μg of CO₂–C g^?1 of soil greater) in NT than that of CT, but this trend was reversed at 10–20 cm depth wherein the C‐min rates were 106 μg of CO₂–C g^?1 of soil greater in CT compared with NT, which is likely because of soil disturbance during the study. Soil cumulative CO₂‐C emissions were greater in the CT system (7.28 g m^?2) than in the NT system (5.19 g m^?2), which is primarily attributed to high soil temperature conditions in the CT system. Sorghum grain yield however was not influenced by the differences in SOC content in this long‐term experiment. Overall, the present study found that long‐term conservation tillage improved SOC stock and reduced carbon loss, thus had a positive impact on soil health and sustainability.  相似文献   

Synthesis,stability and insecticidal activity of 2‐arylstilbenes     

Lindsey G Horty  John F Daeuble  Scott Castetter  Monica B Olson  Frank J Wessels  Nick X Wang 《Pest management science》2019,75(11):3015-3023

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A fine‐scale genetic linkage map reveals genomic regions associated with economic traits in walnut (Juglans regia)     

Mallikarjuna K. Aradhya  Dianne Velasco  Ji‐Rui Wang  Ramesh Ramasamy  Frank M. You  Chuck Leslie  Abhaya Dandekar  Ming‐Cheng Luo  Jan Dvorak 《Plant Breeding》2019,138(5):635-646

A genetic linkage map of walnut containing 2,220 single nucleotide polymorphisms (SNPs) in 16 linkage groups (LGs) was constructed using an F₁ mapping population from a cross between “Chandler” and “Idaho,” two contrasting heterozygous parents. Five quantitative yield traits, lateral fruitfulness, harvest date and three nut traits (shell thickness, nut weight and kernel fill) were then mapped on to linkage groups. A significant quantitative trait locus (QTL) in LG 11 with negative additive effects suggested heterozygote superiority in the expression of lateral bearing. A set of three QTLs explaining ~10% of the variation in harvest date was located in LG 1. Shell thickness, nut weight and kernel fill were under the control of two to three linked pleiotropic QTLs in LG 1 segregating from “Idaho.” The marginal positive additive effects of QTLs for harvest date, shell thickness and nut weight and small negative additive effects for kernel fill suggested that the QTLs had a marginal effect on the expression of these traits.  相似文献   

Transepithelial Transport of Curcumin in Caco-2 Cells Is significantly Enhanced by Micellar Solubilisation     

Jan Frank  Christina Schiborr  Alexa Kocher  Jürgen Meins  Dariush Behnam  Manfred Schubert-Zsilavecz  Mona Abdel-Tawab 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(1):48-53

Curcumin, the active constituent of Curcuma longa L. (family Zingiberaceae), has gained increasing interest because of its anti-cancer, anti-inflammatory, anti-diabetic, and anti-rheumatic properties associated with good tolerability and safety up to very high doses of 12 g. Nanoscaled micellar formulations on the base of Tween 80 represent a promising strategy to overcome its low oral bioavailability. We therefore aimed to investigate the uptake and transepithelial transport of native curcumin (CUR) vs. a nanoscaled micellar formulation (Sol-CUR) in a Caco-2 cell model. Sol-CUR afforded a higher flux than CUR (39.23 vs. 4.98 μg min^?1 cm^?2, respectively). This resulted in a higher P_app value of 2.11 × 10^?6 cm/s for Sol-CUR compared to a P_app value of 0.56 × 10^?6 cm/s for CUR. Accordingly a nearly 9.5 fold higher amount of curcumin was detected on the basolateral side at the end of the transport experiments after 180 min with Sol-CUR compared to CUR. The determined 3.8-fold improvement in the permeability of curcumin is in agreement with an up to 185-fold increase in the AUC of curcumin observed in humans following the oral administration of the nanoscaled micellar formulation compared to native curcumin. The present study demonstrates that the enhanced oral bioavailability of micellar curcumin formulations is likely a result of enhanced absorption into and increased transport through small intestinal epithelial cells.  相似文献   

Phosphorus speciation in cultivated organic soils revealed by P K‐edge XANES spectroscopy     

Frank Schmieder  Jon Petter Gustafsson  Wantana Klysubun  Franz Zehetner  Matthew Riddle  Holger Kirchmann  Lars Bergstrm 《植物养料与土壤学杂志》2020,183(3):367-381

Cultivated organic soils make a significant contribution to phosphorus (P) leaching losses from agricultural land, despite occupying a small proportion of cultivated area. However, less is known about P mobilisation processes and the P forms present in peat soils compared with mineral soils. In this study, P forms and their distribution with depth were investigated in two cultivated Histosol profiles, using a combination of wet chemical extraction and P K‐edge X‐ray absorption near‐edge structure (XANES) spectroscopy. Both profiles had elevated P content in the topsoil, amounting to around 40 mmol kg^?1, and P speciation in both profiles was strongly dominated by organic P. Topsoils were particularly rich in organic P (P‐org), with relative proportions of up to 80%. Inorganic P in the profiles was almost exclusively adsorbed to surface reactive aluminium (Al) and iron (Fe) minerals. In one of the pro‐files, small contributions of Ca‐phosphates were detected. A commonly used P saturation index (PSI) based on ammonium‐oxalate extraction indicated a low to moderate risk of P leaching from both profiles. However, the capacity of soil Al and Fe to retain P in organic soils could be reduced by high competition from organic compounds for sorption sites. This is not directly accounted for in PSI and similar indices. Accumulation of P‐org in the topsoil may be attributable by microbial peat decomposition and transformation of mineral fertiliser P by both microbiota and crops. Moreover, high carbon–phosphorus ratio in the surface peat material in both profiles suggests reduced net mineralisation of P‐org in the two soils. However, advancing microbial peat decomposition will eventually lead to complete loss of peat horizons and to mineralisation of P‐org. Hence, P‐org in both profiles represents a huge potentially mobilised P pool.  相似文献   

Genome-wide association studies in a barley (Hordeum vulgare) diversity set reveal a limited number of loci for resistance to spot blotch (Bipolaris sorokiniana)     

Fluturë Novakazi  Olga Afanasenko  Nina Lashina  Gregory J. Platz  Rod Snowdon  Igor Loskutov  Frank Ordon 《Plant Breeding》2020,139(3):521-535

Spot blotch caused by Bipolaris sorokiniana is an important disease in barley worldwide, causing considerable yield losses and reduced grain quality. In order to identify QTL conferring resistance to spot blotch, a highly diverse worldwide barley set comprising 449 accessions was phenotyped for seedling resistance with three isolates (No 31, SH 15 and SB 61) and for adult plant resistance at two locations (Russia and Australia) in two years. Genotyping with the 50 k iSelect barley SNP genotyping chip yielded 33,818 informative markers. Genome-wide association studies (GWAS) using a compressed mixed linear model, including population structure and kinship, revealed 38 significant marker-trait associations (MTA) for spot blotch resistance. The MTA corresponded to two major QTL on chromosomes 1H and 7H and a putative new minor QTL on chromosome 7H explaining between 2.79% and 13.67% of the phenotypic variance. A total of 10 and 14 high-confidence genes were identified in the respective major QTL regions, seven of which have a predicted involvement in pathogen recognition or defence.  相似文献   

Identifying when it is financially beneficial to increase or decrease fungicide dose as resistance develops: An evaluation from long-term field experiments     

Frank van den Bosch  Jonathan Blake  Paul Gosling  Joe C. Helps  Neil Paveley 《Plant pathology》2020,69(4):631-641

As the frequency of fungicide resistant strains increases in a pathogen population, there is a change in the shape of the response curve of disease severity to fungicide dose. We showed previously, in a theoretical analysis, that such changes can result in an increase or a decrease in the economically optimal dose of fungicide; this depends on how the response curve changes (which is determined jointly by the degree of insensitivity and frequency of a new strain) and the shape of the disease–yield loss relationship (which is a characteristic of the pathogen and crop). Here, we use field dose–response data to estimate economic optimum doses for the control of Zymoseptoria tritici on wheat over a 21-year period. Resistance to fungicide developed to varying degrees against three modes of action (MoA). Changes of optimal dose across years differed according to MoA, but there was an underlying pattern of initial increase in optimal dose, followed by a decrease (ultimately to zero dose at high levels of fungicide resistance). Fungicides are often applied in mixture and analysis shows that, provided the mixture partner is effective, the economic optimal dose increases less as resistance develops than when the fungicide is used as solo product; however, the subsequent decrease in optimal dose remains.  相似文献   

Disorders in pedigree dogs: Assembling the evidence     

Frank W. Nicholas  Claire M. Wade  Peter Williamson 《Veterinary journal (London, England : 1997)》2010,183(1):8-9

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