bluuebunny/crossref_metadata_2025_split huggingface dataset:
Canopy development and tillering of field‐grown crops of two contrasting cultivars of winter wheat (Triticum aestivum) in response to CO2 and temperature
Authors: BATTS G R , ELLIS R H , MORISON J I L , HADLEY P. 
Published: February 2008

Summary.Elevated CO2 (691 cf. 371 /miol CO2 mol‐1 air) and warmer temperatures (over the range 1.0UC below to 1.6oC above ambient) increased light interception by crops of two contrasting cultivars (Hereward and Soissons) of winter wheat (Triticum aestivum L.) during winter growth in the field. The fractional interception of light by the canopy increased more rapidly initially in Soissons than in Hereward, but Hereward showed a much greater response to CO2 (35% increase in Hereward but only 7% in Soissons) at 500oCd after sowing. By terminal spikelet formation, in contrast, fractional interception was greater in Hereward than in Soissons, while the effect of CO2 was the same in both cultivars (9%). Thus, although differences in the relative response of canopy development to CO2 were detected between cultivars initially, differences were negligible during later development. The greater interception of light by the canopy in elevated CO2, at any one temperature, resulted from increased tillering. The number of tillers plant“‘ at terminal spikelet was a linear function of main stem dry mass at this developmental stage but with a greater response in elevated CO2, viz 2.3 and 3.8 tillers g‐1 main stem dry mass at 371 and 691 /μmol CO2 mol‐1 air, respectively; these relations were unaffected by cultivar.
Diagnosis of light leaf spot (Pyrenopeziza brassicae) on winter oilseed rape (Brassica napus) in the UK
Authors: FITT B D L , DOUGHTY K J , GLADDERS P. , STEED J M , SUTHERLAND K G 
Published: February 2008

Summary.Light leaf spot lesions were generally first observed as light green areas on leaves of UK winter oilseed rape crops in January or February and later became brittle and bleached. Elongated lesions, which were brown with indistinct edges, developed on stems in the spring and summer, when lesions were also observed on flower buds, pedicels and pods. Development of diagnostic white pustules (spore masses of Pyrenopeziza brassicae, which erupt through surfaces of infected tissues) for confirmation of light leaf spot infection on symptomless plants or plants with indistinct or ambiguous symptoms in the autumn, winter or spring was enhanced by incubating plants in polyethylene bags. In experiments with artificially inoculated plants, glasshouse‐grown plants exposed in infected crops and plants sampled from crops, white pustules developed at all incubation temperatures from 2oC to 20oC on infected leaves of different cultivars. The period of incubation required before the appearance of pustules decreased as the time that had already elapsed since the initial infection increased. The longest periods of incubation were required at the lowest temperatures (2oC or 5oC) but leaves senesced and abscised from plants most quickly at the highest temperatures (15oC or 20oC), suggesting that the optimal incubation temperature was between 10oC and 15oC.
Improved purification and molecular properties of Omithogalum mosaic virus in Israel
Authors: ZEIDAN M. , COHEN J. , WATAD A. , GERA A. 
Published: February 2008

Summary.Symptoms associated with infection by Omithogalum mosaic virus (OMV) were documented among horticulturally important Omithogalum spp. grown in commercial greenhouses and open fields in Israel. OMV was mechanically transmitted to Chenopodium quinoa and C. amaranticolor. The virus was purified from infected C. quinoa using CsCl step gradient centrifugation. Virus yield of 18–24 mg kg“1 were obtained. Antiserum produced to the purified virus was highly specific in immunoblots and immunosorbent electron microscopy. Reverse transcription ‐ polymerase chain reaction (RT‐PCR) utilising potyvirus‐specific primers and the viral RNA resulted in the amplification of a DNA product of 1275 nucleotides. This PCR product was cloned and sequenced; it encoded an open reading frame of 333 codons and a 3‘ non‐coding region of 275 nucleotides. Analysis of the amino acid sequences of the putative CP of the Israeli isolate of OMV showed 95% similarities to the South African isolate.
The contribution of tomato and alternative host plants to tomato leaf curl virus inoculum pressure in different areas of South India
Authors: RAMAPPA H K , MUNIYAPPA V. , COLVIN J. 
Published: February 2008

Summary.Indian tomato leaf curl virus (ToLCV) (Geminiviridae: Sub‐group III) was detected both in field‐collected and laboratory‐reared B. tabaci using a triple‐antibody sandwich enzyme‐linked immunosorbent assay (TAS‐ELISA). ToLCV was detected in six of the 10 group samples of field collected B. tabaci. ToLCV was also identified in 13 weed species commonly found in Karnataka, both by symptom expression and TAS‐ELISA. ToLCV from c. 61% of infected plants was transmitted successfully to tomato by B. tabaci.Tomato plots were planted at three locations on the University of Agricultural Sciences Campus, Bangalore. Indian tomato leaf curl virus disease (ToLCVD) incidence increased most rapidly when the tomato plot was situated adjacent to an older ToLCVD‐infected tomato field. When the plots were positioned in a dryland or a wetland area, at least 500 m away from any infected tomato fields, the ToLCVD incidence increased less rapidly, although in all sites it was 100% by 11 wk after transplanting. The numbers of B. tabaci caught on yellow traps in all sites increased during weeks 1–3 after transplanting and thereafter remained at between 10–15 adults trap‐1 24 h_1. Adult numbers recorded on tomato plants by direct counts remained approximately constant at 2–4 adults plant“”1.Tomato fields were planted in three taluks (administrative areas) of Karnataka, that had different current and previous histories of tomato production. ToLCVD incidence increased most and least rapidly, respectively, in Kolar taluk where tomato is grown continuously and Doddaballapur tuluk where tomato was grown in the area for the first time. In Malur tuluk, where tomato was grown discontinuously (once a year), the incidence of ToLCVD increased at an intermediate rate.Weed host‐plant species growing near the experimental sites had averages of between 1.5–10.0 B. tabaci nymphs per plant, whereas the tomato plants had only 0.3 nymphs per plant. The percentage parasitism of B. tabaci nymphs on tomato and weed species, respectively, was 0.7% and 2–6%. Nymphs and pupae were parasitised by an Encarsia sp. and Eretmocerus mundus Mercet.The relevance and implications of these findings for the epidemiology and management of ToLCVD in Karnataka State, South India is discussed.
Effect of inter‐cropping bell‐pepper with ginger on plant parasitic nematode populations and crop yields
Authors: SHARMA G C , BAJAJ B K 
Published: February 2008

Summary.During 1994 studies were undertaken to improve ginger (Zingiber officinale Roscoe) yield against the nematodes Pratylenchus penetrans, Meloidogyne incognita, Helicotylenchus dihystera and Tylenchorhynchus mashhoodi in Himachal Pradesh (HP) (India) by inter‐cropping bell‐pepper (Capsicum annum L) in eight different sequences (treatments). Inter‐cropping of “one rhizome of ginger x one plant of bell‐pepper” gave the highest ginger yield (600 g per rhizome). This treatment was completely free from P. penetrans and M. incognita. All treatments with bell‐pepper plants equal to or higher in number to that of ginger rhizomes had higher ginger yields than treatments with ginger alone or with fewer bell‐pepper plants. In the former, populations of P. penetrans and M. incognita were lower than in the latter treatments. The yield of ginger varied irrespective of population densities of H. dihystera and T. mashhoodi, indicating that P. penetrans and M. incognita are the major nematode problems of ginger in HP. Bell‐pepper was a non‐host to P. penetrans and non‐preferred host to M. incognita. This helped to improve ginger yields by making the rhizosphere unfavourable for the development and multiplication of the major ginger nematode pests.
Herbicide resistance and gene flow in wild‐oats (Avena fatua and Avena sterilis ssp. ludoviciana)
Authors: CAVAN G. , BISS P. , MOSS S R 
Published: February 2008

Summary.The process of resistance evolution to fenoxaprop‐P‐ethyl was investigated in the cereal weeds wild‐oats (Avena fatua L. and Avena sterilis ssp. ludoviciana Malzew) at a number of locations in England, including one farm where distinct patches occur within fields. Genetic fingerprints produced using PCR‐based techniques provided evidence for hybridisation between the species and that resistance had spread from one patch to others. The proportion of total variation due to differences between populations (Gst) was estimated at 33^2%, and herbicide‐resistant patches contained on average less genetic diversity than herbicide‐sensitive counterparts: both findings were consistent with a high degree of self‐pollination. It was however concluded that cross‐pollination occurs both within and possibly between species, and that this can result in the spread of herbicide resistance.
Heat tolerance in cowpea: effect of timing and duration of heat stress
Authors: CRAUFURD P Q , BOJANG M. , WHEELER T R , SUMMERFIELD R J 
Published: February 2008

Summary.Reproductive processes and pod yield in cowpea (Vigna unguiculata (L.) Walp), an important crop grown in semi‐arid sub‐Saharan Africa, are adversely affected by high temperature. Genotypic differences in heat tolerance have been identified under hot, long‐days, but it was not known if this tolerance is also exhibited in hot, short‐day environments typical of sub‐Saharan Africa. The objectives of the work reported here were to determine whether heat tolerance identified under hot, long‐days was expressed at the same stages of development under hot, short‐days, and whether responsiveness to temperature was additive and quantitative. A heat‐tolerant (Prima) and heat‐susceptible (IT84S‐2246) cultivar of cowpea were grown in controlled environments under short‐days (12 h day‐1), initially at 30°C/24°C (Mod‐T), and then transferred at 0, 10, 20, 30 and 40 days after emergence (DAE) to 36°C/27°C (High‐T), where they remained for 5, 10 or 20 days duration before returning to Mod‐T. Control plants remained at Mod‐T or High‐T for 50 days, when the first pods were mature and the experiment was terminated. There were significant effects of duration (D) and timing (T) (P < 0.001), and interactions between D × T (P < 0.001), T × genotype (G) (P < 0.01) and D × T × G (P < 0.05) on pod weight plant‐1. Prima was significantly (P < 0.001) more tolerant to high temperature during flowering than IT84S‐2246, confirming that heat tolerance was expressed under hot, short days. The greater heat tolerance of Prima was associated with an ability to maintain peduncle and flower production at High‐T, and with greater podset. The sensitive period in IT84S‐2246 started at floral bud initiation (15–20 DAE), and effects of High‐T thereafter were additive and quantitative.
Alterations in growth of tissue‐cultured tansy (Tanacetum vulgare L.) treated with antibiotics
Authors: KESKITALO MARJO , POHTO ARJA , SAVELA MERVI‐LEENA , VALKONEN JARI P T , SIMON JAMES , PEHU EIJA 
Published: February 2008

Summary.Effects of three antibiotics (cefotaxime, rifampicin and gentamicin) were tested on in vitro shoots cultures of tansy (Tanacetum vulgare L.)‐ These antibiotics were selected because endophytic bacteria isolated from the in vitro shoot cultures of tansy showed that all bacteria were Gram‐negative and their growth was reduced by these three antibiotics. Five isolates were Enterobacteriaceae, three were fluorescent Pseudomonas, and two were aerobic bacteria. Increased concentrations of antibiotics caused usually linear or quadratic changes on the initiation of shoot growth, shoot number, growth rate, and shoot height. These changes and changes in pH of the culture media were tansy genotype‐dependent following treatments with gentamicin. Also, the treatment with rifampicin or cefotaxime showed a genotype‐dependent effect, because they resulted in significantly higher percentage of rooted plants in one of the three tansy genotypes tested. The growth rate and length of shoots were reduced in the media containing both gentamicin and rifampicin, but less so than in media containing both gentamicin and cefotaxime.
Feeding preferences of woodpigeons and flea‐beetles for oilseed rape and turnip rape
Authors: LAMBDON P W , HASSALL M. , MITHEN R. 
Published: February 2008

Summary.Winter turnip rape Brassica rapa ssp. oleifera was shown to have reduced palatability to woodpigeons, enhanced susceptibility to adult flea beetle feeding and reduced susceptibility to larval flea‐beetle infection when compared with winter oilseed rape (B. napus) cultivars in field trials. Levels of leaf waxes were negatively correlated with feeding preferences of adult flea beetles. Analysis of volatiles from damaged leaves showed that while all cultivars produce a similar range of nitriles, cyanoepithioalkanes and isothiocyanates, derived from 3‐butenyl, 4‐pentenyl and phenylethyl glucosinolates, B. rapa leaves produced relatively high levels of 1‐methylpropyl isothiocyanate, although there was significant plant‐to‐plant variation. The possible involvement of this mustard oil glycoside and variation in epicuticular waxes in plant‐herbivore interactions are discussed.
Selection of resistance breaking strains of tomato spotted wilt tospovirus
Authors: LATHAM L J , JONES R A C 
Published: February 2008

Summary.In glasshouse tests, sap from plants infected with 15 different isolates of tomato spotted wilt tospovirus (TSWV) from three Australian states was inoculated to nine genotypes of tomato carrying TSWV resistance gene Sw‐5 or one of its alleles. A further two resistant tomato genotypes were inoculated with four isolates each. The normal response in resistant genotypes was development of necrotic local lesions in inoculated leaves without systemic invasion, but 22/752 plants also developed systemic reactions in addition to local hypersensitive ones. Using cultures from two of these systemically infected plants and following four cycles of subculture in TSWV resistant tomato plants, two isolates were obtained that gave susceptible type systemic reactions but no necrotic spots in inoculated leaves of resistant tomatoes. When these two isolates, DaWA‐1d and ToTAS‐1d, were maintained by repeated subculture for 10 successive cycles in Nicotiana glutinosa or a susceptible tomato genotype, they still induced susceptible type systemic reactions when inoculated to resistant tomato plants. They were therefore stable resistance breaking isolates as regards overcoming gene Sw‐5. When resistance‐breaking isolate DaWA‐1ld multiplied together with original isolate DaWA‐l in susceptible tomato, it was fully competitive with the original isolate. However, when DaWA‐ld and ToTAS‐ld were inoculated to TSWV resistant Lycopersicon peruvianum lines PI 128660R and PI 128660S and to TSWV resistant Capsicum chinense lines PI 152225, PI 159236 and AVRDC CO0943, they failed to overcome the resistance, producing only necrotic local lesions without systemic infection. Thus, although the ease of selection, stability and competitive ability of resistance breaking isolates of TSWV is cause for concern, L. peruvianum and C. chinense lines are available which are effective against them.The effectiveness of the resistance to TSWV in nine tomato genotypes was examined in a field experiment. Spread was substantial in the susceptible control genotype infecting 42% of plants. Resistance was ineffective in cv. Bronze Rebel, 26% of plants developing infection. In contrast, it held up well in the other eight resistant genotypes with only 1–3 or no plants of each becoming infected. Accumulated numbers of Thrips tabaci, Frankliniella occidentalis and F. schultzei were closely correlated with TSWV spread.
Natural infection with raspberry bushy dwarf virus (RBDV) of the putatively RBDV‐resistant red raspberry cultivar Glen Moy, and the demonstration that it does not contain the RBDV resistance gene, Bu
Authors: JONES A TEIFION , McGAVIN WENDY J , MAYO M A , GRAHAM JULIE 
Published: February 2008

Summary.When released to commerce in 1981, the red raspberry cv. Glen Moy was reported to be immune to the Scottish type isolate of raspberry bushy dwarf virus (RBDV‐D200). Field observations of this cultivar in localities where RBDV was prevalent tended to support this claim of its resistance, but in the past 6–10 yr, RBDV infection has been reported in this cultivar in Australasia, USA and in several commercial crops in England. Therefore, experiments were made to investigate the reason(s) for this apparent anomaly using RBDV‐infected material, putatively of cv. Glen Moy, from two locations in southern England and one each from Australia, New Zealand (NZ) and the USA. Genetic fingerprinting of genomic DNA from samples of these five RBDV‐infected raspberry sources confirmed their identity as cv. Glen Moy. Comparisons of some serological and genomic properties of the five Glen Moy RBDV isolates indicated that, whilst they shared many properties with previously well characterised isolates of this virus, they were distinguishable from them. Characterisation of the isolate from NZ maintained in raspberry showed that it did not have a Rubus host range characteristic of resistance‐breaking (RB) isolates, indicating that for this location, and probably also for those of Australia and the USA, RB isolates were not the cause of infection in cv. Glen Moy. When virus‐tested plants of cv. Glen Moy and 45 progeny seedlings from the cross between cv. Glen Moy and the RBDV‐susceptible cv. Autumn Bliss were graft inoculated with RBDV‐D200, all grafted plants became infected indicating that cv. Glen Moy does not contain the RBDV resistance gene, Bu. Possible reasons for the previously reported resistance of cv. Glen Moy to RBDV are discussed.
The effect of rabbit (Oryctolagus cuniculus) grazing damage on the growth and yield of winter cereals
Authors: BELL A C , BYRNE P M , WATSON S. 
Published: February 2008

Summary.In 1986/1987 and 1987/1988 wild rabbits (Oryctolagus cuniculus) were trapped and enclosed in a 0.3 ha site in which two varieties of winter barley (Igri and Panda) and two of winter wheat (Norman and Mission) were grown in a split plot block design experiment. The level of rabbit population was varied to emulate natural variation in numbers throughout the growing season and was regulated to produce a peak density of 77 rabbits ha‐* in the first year, and 33 rabbits ha‐1! in the second year. Grazing was managed by the use of exclosure fences around plots to produce four treatment levels ‐ protected, autumn grazed, spring grazed and totally grazed regimes. Rabbit damage was assessed using stem and leaf damage indices several times through the growth of the crops. Yields were measured in terms of head number, grain weight and total yield.There was no evidence of varietal preference among the four cereal varieties on the basis of damage assessments. In the first year the totally grazed treatment led to an increase in the number of unripe heads present at harvest which would indicate a delayed harvest date in a field crop. Winter wheat showed a trend towards higher yield loss in spring‐damaged plots, possibly linked to the time of tillering in this crop. Yield losses overall were highest in those plots grazed in either the autumn or throughout the entire season. The level of peak rabbit population did not appear to influence the degree of loss in either year. The results indicate that there may be a threshold of rabbit damage early in the growth of the crop which contributes most to the yield loss. This emphasises the importance of protecting a winter cereal crop at its establishment phase.
Antioxidant systems in the leaf apoplast compartment of Pinus pinaster Ait. and Pinus radiata D. Don. Plants exposed to SO2
Authors: DURAN‐CARRIL M V , BUJAN C RODRIGUEZ 
Published: February 2008

Summary.The activities of guaiacol peroxidase (GuPOD), ascorbate peroxidase (ASAp), superoxide dismutase (SOD) and ascorbate/glutathione cycle (AGC) enzymes, together with ascorbate (ASC) and glutathione contents, were determined in apoplastic‐fluid and cell‐wall fractions of needles of Pinus pinaster Ait. and Pinus radiata D. Don. exposed for up to 6 months to SO2 (0.01 ppm or 0.30 ppm) in fumigation chambers. AGC enzyme activities (monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) were in all cases undetectable, as was glutathione content. In needles of P. pinaster plants exposed to SO2, ascorbate content and all enzyme activities considered (except AGC enzymes) increased. The increases were most marked in response to the higher SO2 concentration. In needles of P. radiata, similar but less marked responses were observed. These findings suggest a) that enzyme activities and ascorbate contents increase in order to deal with the reactive oxygen intermediates produced during long‐term contamination with SO2, and b) that P. pinaster has more effective defences against contamination of this type than P. radiata.
The retting of flax after preservation with sulphur dioxide
Authors: EASSON D L , MOLLOY R. , ANDERSON R. , SHARMA H S S 
Published: February 2008

Summary.Experiments were carried out to compare the retting of moist flax preserved with sulphur dioxide with that of green dried flax, using whole straw samples. When retted in water at either a constant 20°C or 28°C dried flax was fully retted after 15 and 10 days respectively whereas the sulphur dioxide treated flax (20 g sulphur dioxide kg“1 flax DM) had undergone almost no retting after 20 days at 20dC or 10 days at 28°C. Pre‐soaking the treated flax for 24 h in water and changing the acidified water, raised the pH of the retting liquor to a more normal value but did not significantly increase the rate of retting. Addition of the pectinase enzyme preparation ‘Flaxzyme’ to retting liquor at the rate of either 1.5 g kg‐1 or 3.0 g kg‐1 water, and at a constant temperature of 20°C, substantially increased the rate of retting of both sulphur dioxide treated and dried flax. Optimum degree of retting was achieved at 24 h with the treated flax and at 97 h with the dried flax. Pre‐rinsing of the sulphur dioxide treated straw only served to reduce the rate of retting. It was concluded that natural water retting of sulphur dioxide treated flax is retarded by the presence of acidic residues of sulphur dioxide, while enzyme retting is enhanced by these. In further smaller scale experiments using bundles of cut flax straw Flaxzyme was added at concentrations ranging from 0–8.0 ml litre 1 to containers containing flax in water at ratios from 1:10 to 1: 600 flax:water and the producion of galacturonic acid was used as an indicator of retting progress. Retting took place more rapidly at higher flax to water ratios for a given enzyme concentration. This effect was attributed to the lower pH of higher flax to water ratios which created pH conditions closer to the pH optimum for the retting enzymes. When enzyme retting was compared at a range of buffered pH's the optimum was pH 4.0. At a buffered pH of 4.0 and a temperature of 19°C, retting of sulphur dioxide treated moist flax (flax to water ratio of 1:10) was achieved with Flaxzyme concentrations as low as 0.5 ml litre”‘,much lower than the previously reported minimum of 3.0 ml litre’.