bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of Brussels sprout seedling establishment from ungerminated and low‐moisture‐content germinated seeds
Authors: FINCH‐SAVAGE W. E. 
Published: February 2008

SUMMARYThe moisture content of newly‐germinated Brussels sprout seeds (radicles 1 ± 0·5 mm long) was reduced to 16% without loss of viability when compared with untreated newly‐germinated seeds. Seedling emergence and growth from these low‐moisture‐content germinated (LMCG) seeds and ungerminated seeds were compared in cellular trays and seedbeds. A greater number of seedlings emerged more uniformly and more rapidly from LMCG seeds than from ungerminated dry seeds, leading to larger, more uniform seedlings for subsequent transplanting.Post‐germination separation in sucrose solutions before drying resulted in a seed batch with 98% of germinated seeds. As there was a positive relationship between the rate of germination and subsequent seedling growth, it is suggested that germinated‐seed separation techniques could be used to select the most vigorous seedlings.
Further studies on double‐stranded RNA species from raspberry plants infected with aphid‐borne viruses
Authors: JONES A. T. , MITCHELL M. J. 
Published: February 2008

SUMMARYAnalysis by electrophoresis in polyacrylamide gels, followed by silver staining, of dsRNA extracted from many samples of raspberry leaves infected with raspberry leaf mottle virus (RLMV) and/or raspberry leaf spot virus (RLSV) failed to detect reliably any significant quantities of dsRNA species in excess of 1·0 × 106mol. wt. This contrasts with results reported from Canada where three dsRNA species of estimated mol. wt 2·6 × 1061·6 × 106and 1·1 × 106were consistently associated with infection with RLSV but none were associated with RLMV. However, in Scotland, four dsRNA species of estimated mol. wt 2·4 × 1061·6 × 1060·7 × 106and 0·3 × 106were detected in raspberry infected with apple mosaic ilarvirus. These results suggest that the dsRNA species reported from Canada are not those of RLSV but are probably those of a second virus, possibly an ilarvirus, which occurs together with RLSV and/or induces similar symptoms. A few samples from plants infected with RLMV and RLSV contained very small amounts of two dsRNA species of estimated mol. wt 4·7 × 106and 4·5 × 106. It is not known whether these species are those of RLMV and RLSV.
A marking device for the identification and measurement of growth zones in seedlings with minimum mechanical stress1
Authors: JONES RUSSELL S. , MITCHELL CARY A. 
Published: February 2008

SUMMARYA device was designed to mark the growth zones of elongating seedling stems rapidly and accurately without exposing the tissue to mechanical stress. The device consists of a spring‐loaded clamp, two plastic, grooved holders attached to either side of the open end of the clamp, a narrow foam pad to cushion and support the plant tissue, and a narrow nylon marking head. The marking head contains flat‐topped ridges, 0·5 mm in width, machined such that the ridges are 2 mm (± 0·1) apart. Marking is accomplished using India ink. The procedure is rapid, precise, relatively inexpensive to build and operate, and does not require sophisticated or expensive instrumentation to obtain meaningful data. With practice, up to 100 seedlings may be uniformly marked in one hour. Tests using dark‐grown soybean (Glycine max), sunflower (Helianthus annuus), and pea (Pisum sativum) show that the device does not itself cause a reduction in growth.
Wound‐induced changes in DIMBOA (2, 4 dihydroxy‐7‐methoxy‐2H‐1, 4 benzoxazin‐3(4H)‐one) concentration in maize plants caused by Sesamia nonagrioides (Lepidoptera: Noctuidae)
Authors: GUTIERREZ C. , CASTAÑERA P. , TORRES V. 
Published: February 2008

SUMMARYTwo maize (Zea mays) inbred lines, A‐619, (high DIMBOA content) and W‐117 (low DIMBOA content) were artificially infested, at similar physiological stages, with 10 first‐instar larvae of Sesamia nonagrioides. The DIMBOA concentration in stem and leaf tissues of damaged and undamaged plants was measured quantitatively in response to larval attack. After 60 h of infestation, both inbred lines were found to respond to insect attack by increasing significantly (P< 0·01) the DIMBOA content in leaf tissues compared with uninfested controls. Similar results were observed 5 days after infestation. No significant differences were found between the stem tissues of the two cultivars during this period. After 9 days infestation, significant increases (P <0·01) could still be found in the stem tissues of the two lines, these showing signs of wounding due to direct insect damage. Thereafter, until day 25 following infestation (the last day of measurement) no significant increased level of DIMBOA was recorded in stem and leaves of the infested lines in any sampling. The production of this compound appears to be a physiological response of the plant to attack induced by physical disruption of its tissues.
Integrated control of potato cyst nematodes using small amounts of nematicide and potatoes with partial resistance
Authors: ALPHEY T. J. W. , PHILLIPS M. S. , TRUDGILL D. L. 
Published: February 2008

SUMMARYThe control of potato cyst nematode (PCN) by less than approved amounts of nematicide combined with partially resistant potato clones was studied in a series of field experiments. On a site heavily infested with Globodera pallida only the most resistant clone (12380ac2) decreased the population density in untreated soil. With aldicarb at its full approved rate (3·36 kg ha‐1) numbers of PCN were decreased under all the genotypes, including the non‐resistant Maris Piper. Aldicarb at 1·68 kg ha‐1significantly decreased populations on all clones except 12380ac2. Aldicarb at 0·84 kg ha‐1still significantly decreased population densities and multiplication rates of G. pallida on two clones with intermediate resistance (12243acl and 11233ab22). At two G. rostochiensis sites with light infestations nematode multiplication rates were greater and the control given by aldicarb and partially resistant genotypes of potato was not as great as that at the site with G. pallida.Tuber yields were not increased by the application of aldicarb at the G. rostochiensis infested sites. However, at the site heavily infested with G. pallida the yield of the most intolerant genotype (12380ac2) was increased seven‐fold by the full rate of aldicarb (3·36 kg ha‐1) and four‐fold by the quarter rate (0·84 kg ha‐1)‐Yield of the most tolerant genotype (12243acl) was unaffected by the application of aldicarb.
The size distribution of potato tubers and its application to grading schemes
Authors: GLASBEY C. A. , McRAE D. C. , FLEMING J. 
Published: February 2008

SUMMARYThe weight, length, breadth and depth were measured for each of 10 000 potato tubers. These were samples over 3 years of the 10 most commonly grown UK maincrop varieties. Volume, square‐mesh riddle size and average projected area were also measured in the final 2 years. A multivariate log‐normal distribution was found to give a good fit to the data. Illustrations are presented of how this distribution can be used to assess grading schemes.
Involvement of ethylene in the disease caused by Botrytis cinerea on rose and carnation flowers and the possibility of control*
Authors: ELAD YIGAL 
Published: February 2008

SUMMARYEthylene production by flowers, petals and leaves of rose was correlated with severity of grey mould. However, when the host became completely macerated, ethylene production diminished. Ethylene production by Botrytis cinerea grown on autoclaved flowers which were supplemented with methionine was negligible. Methionine spray, incubation with ethylene, or precooling of flowers at 4°C increased disease incidence considerably. Ethylene also induced susceptibility of carnation flowers to attack by B. cinerea. On the other hand, sprays of silver thiosulphate (STS) aminooxyacetic acid (AOA) and aminoethoxyvinylglycine (AVG) decreased disease severity in rose petals and leaves inoculated with mycelial plugs or conidia. Treatment of cut rose flowers with STS (by dipping) or AOA (by spraying) significantly decreased disease incidence during subsequent incubation at 20 and 10°C. This suggests a treatment for reducing grey mould damage in flowers transported overseas.
A single wheatgrass chromosome reduces the concentration of barley yellow dwarf virus in wheat
Authors: BRETTELL R. I. S. , BANKS P. M. , CAUDERON Y. , CHEN X. , CHENG Z. M. , LARKIN P. J. , WATERHOUSE P. M. 
Published: February 2008

SUMMARYSeedlings of a series of addition or substitution lines of wheat containing different Thinopyrum intermedium chromosomes were inoculated with the PAV and RPV serotypes of barley yellow dwarf virus (BYDV). Reduced virus titres in infected plants were ascribed to a single pair of homoeologous group 7 chromosomes from Th. intermedium in the disomic addition lines L1 and TAF 2. The group 7 chromosome is associated with red pigmentation of coleoptiles, which was also observed in two lines ditelosomic for the α arm of the chromosome. However, when infected with the PAV serotype of BYDV, the ditelosomic lines had normal virus titres and it is concluded that potential determinants of BYDV resistance are located on the β arm of the Group 7 chromosome.
Factors affecting orchard colonisation by the black‐kneed capsid (Blepharidopterus angulatus (Hemiptera:Miridae)) from alder windbreaks
Authors: GANGE A. C. , LLEWELLYN M. 
Published: February 2008

SummaryThe colonisation of orchards by Blepharidopterus angulatus (the black‐kneed capsid bug) from alder windbreaks was investigated, to determine its use as a biological control agent of orchard pests. The aphid Pterocallis alni provides an abundant and acceptable food for the capsid on alder. The key capsid mortality factor on windbreaks was the loss of adult females through migration. Clipping the windbreak prior to the aphid population peak resulted in male capsids migrating and females remaining, while clipping after the aphid population peak resulted in both sexes migrating to nearby orchards. Guidelines are given for windbreak management as part of a system of integrated orchard pest control.
Environmental constraints on the efficiency of selection for malting quality in barley
Authors: ELLIS R. P. , SWANSTON J. S. , TAYLOR K. , BRUCE FRANCES M. 
Published: February 2008

SummaryA range of screening tests has been applied to samples of barley from breeders' trials to evaluate the usefulness of rapid tests. The prediction of the malting potential of genotypes over seasons was best achieved by the use of hot water extract measurements. Environmental effects can result in a poor relationship between hot water extract and grain characters such as β‐glucan content and thousand corn weight. Hot water extract varied considerably over sites, but results relative to a control cultivar were consistent provided that trials in which material malted poorly were eliminated from the comparisons.
Predicting spring oviposition by raspberry cane midge from accumulated derived soil temperatures
Authors: GORDON S. C. , BARRIE I. A. , WOODFORD J. A. T. 
Published: February 2008

SummaryAn accumulated soil temperature model is described which calculates the first oviposition date for overwintered populations of the raspberry cane midge (Resseliella theobaldi). The model uses values for mean 10 cm soil temperature, derived from daily maximum and minimum air temperatures and 10 cm soil temperature at 0900 GMT. It was developed by minimising the variation between observed dates for the start of oviposition over an 8‐yr period and accumulated air or soil temperature, using a series of base temperatures. The best fit was obtained with soil temperatures accumulated above a base temperature of 4°C. Oviposition was predicted to start when the daily accumulated soil temperature reached 339°C days above a base temperature of 4°C.Field observations and model predictions suggested that emergence and oviposition dates were influenced by the direction of the slope of raspberry plantations. To compensate for this, an empirical correction has been incorporated into the model to advance or retard the predicted oviposition date by adjusting the estimated maximum soil temperature to allow for aspect. The geographical variation between dates for first oviposition was simulated by running the model for nine meteorological sites in the UK in 1985 and 1986.
Cereal aphids and the infectivity index for barley yellow dwarf virus (BYDV) in northern England
Authors: McGRATH P. F. , BALE J. S. 
Published: February 2008

SummarySuction traps at Leeds University Farm, N. Yorkshire, monitored aerial populations of cereal aphids over three autumns. Different migration patterns were observed between the four main species, Sitobion avenae, Metopolophium dirhodum, Rhopalosiphum padi and R. insertum. The relevance of these patterns to the epidemiology of barley yellow dwarf virus (BYDV) is discussed.Transmission tests revealed S. avenae to be the major vector of BYDV, rather than R. padi, which is responsible for disease outbreaks in the south and west of Britain. An Infectivity Index (II) of 50 has been advocated for R. padi‐transmitted BYDV, above which economic damage is likely to occur. This value is shown not to be applicable to the Vale of York, and methods of adapting the data are proposed. Such adjusted II values depend on the behaviour and reproduction of the aphids during the transmission tests, and produce II values that correlate well with levels of field infection in the area.
Climatic factors influencing spore production in Alternaria brassicae and Alternaria brassicicola
Authors: HUMPHERSON‐JONES F. M. , PHELPS KATHLEEN 
Published: February 2008

SummarySporulation in A. brassicae and A. brassicicola on naturally‐infected leaf discs of oilseed rape and cabbage required humidities equal to or higher than 91.5% and 87% r.h. respectively. The optimum temperatures for sporulation were 18–24°C for A. brassicae and 20–30°C for A. brassicicola at which temperatures both fungi produced spores in 12–14 h. Above 24°C sporulation in A. brassicae was inhibited. At sub‐optimal temperatures sporulation times for A. brassicicola were significantly longer than for A. brassicae with the differences increasing with decrease in temperature. Interrupting a 16‐h wet period at 20°C with a period of 2 h at 70% or 80% r.h. did not affect sporulation in either fungus but a dry interruption of 3–4 h inhibited sporulation in both. Exposure of both fungi to alternating wet (18 h at 100% r.h., 20°C) and dry periods (6 or 30 h at 5565% r.h., 20°C) did not affect the concentration of spores produced in each wet period. Sporulation times were not affected by either the host type of the age of the host tissue. White light (136 W/m2) inhibited sporulation in A. brassicae with the degree of inhibition increasing with increasing light intensity. The effect of light on sporulation in A. brassicicola was not tested.
Yield and persistency of contrasting white clover populations grown in pure swards and in mixed swards with S.23 perennial ryegrass
Authors: EAGLES C. F. , OTHMAN O. B. 
Published: February 2008

SummaryTen contrasting white clover populations were grown as spaced plants, in pure clover swards and in mixed swards with S.23 perennial ryegrass. Four of the populations were also tested for tolerance of low temperatures.In the establishment year, the autumn yields of populations were correlated with leaf size. However, during the severe winter which followed, populations with large leaves, particularly those of Mediterranean origin, suffered extensive stolon kill. This winter damage reduced the spring yields and total annual yields of populations with large leaves, so that leaf size and total annual yield were not correlated in the year after sowing.Stolon kill was positively correlated with autumn growth activity as measured by leaflet size and stolon internode length in October. Stolon kill during winter was correlated with cold tolerance of naturally‐hardened stolon apices, assessed in artificial cold tests.
The lack of enzymic browning in the wild potato species Solanum hjertingii compared with commercial Solanum tuberosum varieties
Authors: GUBB I. R. , HUGHES J. C. , JACKSON M. T. , CALLOW J. A. 
Published: February 2008

SummaryEnzymic browning of tuber tissue was evaluated quantitatively for 50 genotypes, representing seven accessions, of Solanum hjertingii, a wild potato species from north‐east Mexico, together with five commercial varieties of Solanum tuberosum with a known range of enzymic browning.Ninety‐four percent of S. hjertingii clones examined showed less browning than the commercial varieties, with 66% exhibiting half the ‘potential browning’ (a measure of the total enzymic browning resulting from disruption of cellular compartmentalisation in that system) of cv. Maris Piper, a low enzymic browning cultivar. Of these clones, 18 showed no visual discoloration when sliced. Results clearly indicate that the lack of enzymic browning in S. hjertingii is a ‘true’ character.The efficiency of one subjective and two objective methods for obtaining different measures of enzymic browning was assessed. Potential browning of a rehydrated freeze‐dried powder was adopted as the most efficient technique for screening enzymic browning.
Effects of plant growth regulators on tiller bud outgrowth in uniculm cereals
Authors: WOODWARD E. J. , MARSHALL C. 
Published: February 2008

SummaryPlant growth regulators were applied either to seeds or to leaves of uniculm selections of barley and wheat. None of the treatments stimulated the growth and development of tiller buds in the barley selection. In contrast, in wheat the development of tiller buds was readily stimulated and tillers were produced following treatment with Terpal, Cerone, TIBA or nitrate. In Terpal and Cerone treated plants, the stimulation of tiller bud outgrowth and tillering was accompanied by a marked retardation of growth in the main shoot. The growth of the tillers was however not sustained in any of the treatments, and so at maturity all plants were virtually uniculm. The results are discussed in relation to the different overall response of the two species, the death of tillers, and the hormonal regulation of tiller bud development.
Salt tolerance of Agaricus bisporus in relation to water stress and toxicity of sodium ions
Authors: AWAD A. S. , NAIR N. G. 
Published: February 2008

SummaryUsing NaCl or polyethylene glycol (PEG) solutions to progressively decrease the external osmotic potential of the peat casing of the growing medium used to culture the mushroom Agaricus bisporus resulted in proportionately decreased yields of sporophores. Over the range of ‐0.07 to ‐0.37 MPa, the extent of decrease in yield was similar with both types of osmoticum. However, with further decrease in external osmotic potential (from ‐0.37 to ‐0.62 MPa) there was a further proportional decrease in sporophore yield with PEG but a complete suppression of sporophore production with NaCl. Treatments with both NaCl and PEG decreased the concentrations of P, Mg, K, Fe and Mn, but not N and Cu, in sporophore dry matter. Treatment with NaCl solutions increased the concentrations of Na and CI ions in sporophore dry matter and decreased the concentration of Ca; PEG solutions had no effect. Ion toxicity associated with excessive accumulation of Na and C1 ions, or ionic imbalance associated with the concomittant decrease in Ca ions appear to be additional factors to osmotic stress in decreasing yield of sporophores when the growing medium becomes highly saline. The critical concentration of NaCl which caused 10% reduction in sporophore yield was 28 mM; A. bisporus is, therefore, moderately salt‐sensitive.
The spread of apple brown rot (Monilinia fructigena) by insects
Authors: LACK K. J. 
Published: February 2008

SummaryField and laboratory experiments were carried out to compare the spread of apple brown rot (Monilinia fructigena) by free aerial transmission of conidia, with insect spread of the pathogen. Significantly more brown rot developed on injured apples which had been visited by insects than on unvisited ones. The results obtained suggest that insects play an important role in aetiology of the disease, especially under conditions unsuitable for abiotic spread.
Molecular cloning of the genome of the carlavirus potato virus S: biotinylated RNA transcripts for virus detection in crude potato extracts
Authors: EWEIDA M. , SIT T. L. , ABOUHAIDAR M. G. 
Published: February 2008

SummaryA cDNA library of potato virus S (PVS) in plasmid pBS+was produced. Insert sizes of two selected overlapping cDNA clones were 1.6 and 4.0 kbp which represent about 75% of the genomic length. Restriction enzyme mapping, hybridisation and in vitro transcription were used to determine the sense and orientation of the inserts in relation to native PVS RNA. The 4.0 kbp insert was used to produce biotinylated DNA or RNA probes for the detection of PVS and its RNA in infected potato plants. In dot‐blot hybridisation biotinylated probes were highly specific with virtually no background coloration. As little as 20 femtograms of PVS RNA could be easily detected in crude plant extracts.
A field cage method for assessing resistance to turnip root fly in brassicas
Authors: BIRCH A. N. E. 
Published: February 2008

SummaryA field cage method was evaluated as an alternative to field trials for identifying sources of resistance to turnip root fly in brassicas. This involved the controlled release of adult flies and the use of egg traps to quantify egg‐laying on potted plants. Overall levels of resistance to Delia floralis, and its components, were assessed for 15 swede genotypes. Significant levels of antixenosis and antibiosis type resistance were identified in several cultivars and breeding lines. There was a close agreement between the field cage results and those from previous field trials, using comparable susceptible and resistance control cultivars. Compared with field selection, the field cage method reduced by c. 40% the time required to quantify resistance and each of its components.
Effectiveness of assessment of vigour and productivity in young vs old bushes and mature clones of tea (Camellia sinensis)
Authors: NYIRENDA H. E. 
Published: February 2008

SummaryThe effectiveness and validity of assessment of bush vigour as expressed by bush area, shoot number and yield in selecting for high yielding clones in tea was tested by comparing the field performance of 50 source bushes when they were 4 yr old in 1977/78 with that of the same bushes when they were 13 yr old in 1986/87 and also with that of the 8 yr old vegetatively propagated plants (clones) derived from them and transplanted to the field in December 1979.Apparently vigorous bushes produced the highest yield. The three characters measured in mature source bushes and, to a lesser extent, clonal derivatives were positively correlated with measurements in young source bushes. Seven of the best yielding source bushes and five of the best clones in 1986/87 were present in the 10 highest yielding source bushes identified in the 1977/78 season.Assessment of bush area and shoot number was confirmed as an effective and valid method of identifying a small, highest yielding group of source bushes from a large population of seedling tea which should go for rooting assessment and further more thorough screening of yield.