bluuebunny/crossref_metadata_2025_split huggingface dataset:
The setting of rates of development of wheat plants at crop emergence: Influence of the environment on rates of leaf appearance
Authors: HAY R. K. M. , DELÉCOLLE R. 
Published: February 2008

SummaryExamination of the time courses, expressed in terms of accumulated temperature over 0°C, of leaf appearance of fifteen sowings of winter wheat, including five cultivars, over three seasons at Auchincruive, revealed several examples of bi‐linear rather than linear responses. Stepwise linear regression analysis, varying the temperature threshold by intervals of 1°C, showed that a linear relationship could be obtained for each sowing, but the appropriateness of this analysis is questioned. An alternative interpretation, that such changes in rate do have biological rather than purely statistical significance, is supported by the fact that, when they occurred, they coincided with the change in rate of spikelet initiation by the stem apex. Furthermore, similar relationships between leaf appearance and reproductive development have been demonstrated for perennial ryegrasses. Analysis of each sowing also revealed the existence of sub‐populations of plants with different rates of leaf appearance and final leaf numbers, but with synchronous phenologies. These findings are discussed in relation to the coordination of the development of apex and leaves, and the environmental cues required to ensure this coordination.
Comparison of scales used for categorising the development of wheat, barley, rye and oats
Authors: LANDES A. , PORTER J. R. 
Published: February 2008

SummaryA review of the scales used to assess the development of cereals is presented. Twenty‐three scales are identified and they are separated into those that codify the external development of plants and those that describe events at the apical meristem. Comparison of the scales is made for wheat, barley, rye and oats, where this is possible. Attention is drawn to the divergence in the descriptions of similar plants on different scales. Theoretical aspects of the general usage of developmental scales are also discussed.
Effect of manganese toxicity on growth and N2 fixation in groundnut, Arachis hypogaea
Authors: NAMBIAR P. T. C. , ANJAIAH V. 
Published: February 2008

SummaryThe development of manganese (Mn) toxicity symptoms and its effects on the growth, nodulation, and nitrogen fixation of groundnut genotypes were examined using a quartz‐sand/solution culture system. The 11 genotypes tested all accumulated considerable concentrations of manganese (1.04–3.07 mg g‐1dry matter) when supplied with 15 μg Mn ml‐1of nutrient solution daily. Toxicity symptoms differed between genotypes: some showed no visual effects, some produced marginal leaf spots, and others developed marginal leaf spots coupled with an inward rolling of the margins of the younger leaves. The growth of one genotype (ICG 5394) grown with inorganic nitrogen as its source of N was more severely affected by Mn toxicity than when dependent on symbiotic fixation for its nitrogen.
Stimulation of sugar‐beet hypocotyl extension with potassium nitrate
Authors: DURRANT M. J. , MASH S. J. 
Published: February 2008

SummarySteeping sugar‐beet seeds in an aqueous thiram suspension, as now used commercially in the UK, makes seedling emergence more rapid and increases the number of plants established. This study investigated whether the potassium and nitrate, removed by steeping, were needed to stimulate subsequent hypocotyl growth. Experiments under controlled conditions showed that re‐incorporation of KNO3 by adding the salt to the steeping solution or, less wastefully during pelleting, slightly slowed root protrusion but made hypocotyl extension more rapid, particularly under dry conditions. There were indications that placement of KNO3 under the seed would be better. Nevertheless, in the field where recommended amounts of fertiliser were applied, incorporation of about 5 g KNO3/kg seed during pelleting was consistently beneficial following the four sowings. This amount decreased the time to half‐final emergence by 0.3 days, gave 3% more established plants and, with the later sowings, increased dry weight in mid‐May by 10%.
Tolerance of cotton to Meloidogyne incognita as influenced by phosphorus fertiliser and a vesicular arbuscular mycorrhizal fungus
Authors: PRICE N. S. , HUSSEY R. S. , RONCADORI R. W. 
Published: February 2008

SummaryCotton was grown in soils of differing phosphorus levels with and without a mycorrhizal fungus and with a range (0 to 3200 eggs/ 100 c‐3 soil) of Meloidogyne incognita eggs added. Tolerance of cotton to M. incognita did not differ between plants grown in different soils with or without the mycorrhizal fungus, though plant size could differ markedly. Plant tolerance was increased by a delay in adding nematodes.
A rapid technique to predict malting quality in barley prior to harvest
Authors: SWANSTON J. S. , WE I. A. CO 
Published: February 2008

SummarySamples of grain from three spring barley cultivars of differing malting quality were collected at regular intervals during four weeks prior to harvest. The samples were dried, then assessed for relative grain hardness using the “Milling Energy” test. Ranking order of the cultivars for this character, which relates strongly to malting quality, was unaltered throughout. In a further experiment, it was demonstrated that selection for milling energy could be successfully practised on oven‐dried grain collected six weeks after ear emergence.
Nitrate accumulation in vegetables and its relationship to quality
Authors: BLOM‐ZANDSTRA MARGARETHA 
Published: February 2008

SummaryMany plants, especially leafy vegetables, accumulate nitrate under low light conditions as uptake of nitrate exceeds reduction. Nitrate may harm the health of the consumer as it can be converted to nitrite causing methaemoglobinaemia or carcinogenic nitrosamines. To take directional measures during the growth of vegetables which will decrease the nitrate content, physiological knowledge about the nitrogen economy of the plant is needed. In this review the physiological role of nitrate as osmoticum and its relationship with carbon utilisation will be described; some practical implications for growers and the consequence for quality of the product will be discussed.
Transpuparial transmission of Kashmir bee virus and sacbrood virus in the honey bee (Apis mellifera)
Authors: ANDERSON DENIS L. , GIBBS ADRIAN J. 
Published: February 2008

SummaryWhen particles of Kashmir bee virus (KBV) and sacbrood virus (SBV) were fed to larvae of the honey bee, Apis mellifera, in Australian colonies, the resulting pupae became in apparently infected. There was no statistically significant difference in the susceptibility of 1, 2, 3 or 4‐day‐old larvae for either virus, but 5‐day‐old larvae were significantly less susceptible to SBV than younger larvae. There was no significant difference in the proportions of pupae that became in apparently infected when, as larvae, they were fed various concentrations of each virus, but significantly more larvae were removed from their cells when fed concentrated preparations of each virus than when fed diluted preparations. Susceptible larvae that became in apparently infected with KBV and SBV developed normally into in apparently infected pupae and later, emerged as in apparently infected worker bees.
Epidemiological studies of Colletotrichum gloeosporioides disease of cocoa
Authors: MOHANAN R. CHANDRA , KAVERIAPPA K. M. , NAMBIAR K. K. N. 
Published: February 2008

SummaryThe intensities of foliar infection (leaf blight and shot hole) and pod rot, caused by Colletotrichum gloeosporioides, were recorded from a cocoa‐areca mixed garden and a cocoa‐monocrop garden during 2 years. The intensity of pod rot was recorded from both the gardens. The intensities of leaf blight and shot hole gradually increased from July, reached a peak during September‐November, decreased thereafter and reached the lowest level during April‐June. Increase in leaf infection was associated in both plantings and in both years with the period of rain (June‐November). The phylloplane population of C. gloeosporioides also increased during June‐November when the temperature tended to be low and constant with high rainfall and relative humidity. During this period there were few susceptible stages of pods (cherelles and young pods) and pod infection was very low. Nearly mature pods were free from infection. I n both years, pod infection was more in the cocoaareca mixed garden than' in the cocoa‐monocrop; it was observed during January‐May, when the susceptible stages were mostly prevalent but when the C. gloeosporioides population was low and the climatic factors appeared to be relatively unfavourable. This may be one reason for the lesser incidence of pod rot when compared to foliar disease.
The histology of lesion development in raspberry canes infected by Elsinoe veneta
Authors: WILLIAMSON B. , McNICOL. R. J. 
Published: February 2008

SummaryA histological survey was made of the canes of several raspberry genotypes inoculated in the field and glasshouse with Elsinoe veneta. Acervuli bearing conidia developed on all genotypes and hyphae penetrated the cortex, polyderm and phloem inducing extensive cell divisions, utilisation of starch reserves and deposition of suberin and lignin‐like materials in these tissues.The results indicated that the polyderm was invaded via the passage cells at an early stage in its development. Phloem fibre cells surrounded by lignified middle lamellae were rarely infected, but since the fibre bundles did not form a complete sheath around the vascular tissues, hyphae spread between the bundles to invade the phloem in all genotypes. The deposition of suberin and lignin‐like materials in host cells in the cortex, phelloid cells of the polyderm and phloem partially restricted the spread of mycelium.
Production of cloned cDNA from a Swedish barley yellow dwarf virus isolate
Authors: EWEIDA MOHAMED , OXELFELT PER 
Published: February 2008

SummaryA cDNA library was produced from the RNA of a Swedish MAV‐like isolate of barley yellow dwarf virus (BYDV). The procedure involved random priming and the ds cDNA was cloned into the EcoRl site of the plasmid pUC19. Among the clones obtained some hybridised specifically with MAV‐like isolates whereas others also hybridised with PAV‐like isolates. Only very weak hybridisation was observed with an RPV‐like isolate. An Australian cDNA clone, reported to be PAV‐specific (pBY82, Waterhouse, Gerlach & Miller, 1986), hybridised with Swedish MAV‐like but not with PAV‐like isolates. Probes prepared from the clones detected virus in plant extracts by dot‐blot hybridisation with sensitivity greater than that of ELISA. Virus was also readily detected in extracts of viruliferous aphids.
Particle properties of parsnip yellow fleck virus
Authors: HEMIDA S. K. , MURANT A. F. 
Published: February 2008

SummaryParticle preparations of parsnip yellow fleck virus (PYFV) isolates A‐421 and P‐121, representing the two major serotypes, were made by clarifying leal extracts with ether or butan‐1‐ol and concentrating the virus particles by precipitation with polyethylene glycol and differential centrifugation. The preparations contained c. 31 nm‐diameter particles comprising two sedimenting components. Top component (T) consisted of stain‐penetrable protein shells with A260/A280= 0.8–0.9, sedimentation coefficient (S20) = 56 S (A‐421) or 60 S (P‐121), and buoyant density = 1.297 g/cm3. Bottom component (B) consisted of nucleoprotein particles, not penetrable by negative stain, with A260/A280= 1.9, sedimentation coefficient (S020.w) = 148 S (A‐421) or 153 S (P‐121), and buoyant density = 1.520 g/cm3 (A‐421) or 1.490 g/cm3 (P‐121). Yields of B component particles were up to c. 1 mg/100 g leaf tissue (both isolates); yields of T component particles were up to c. 0.6 mg (A‐421) or 5.5 mg (P‐121) per 100 g leaf tissue. PYFV particles were found to contain a single RNA species (mol. wt c. 3.4 × 106, c. 9800 nucleotides), constituting 40% of the particle weight, and three polypeptide species, of mol. wt (× 10 3)30, 26 and 24 (A‐421) or31, 26 and 23 (P‐121).
Preparation of mycoplasma immunogens from plants and a comparison of polyclonal and monoclonal antibodies made against primula yellows MLO‐associated antigens
Authors: CLARK M. F. , MORTON ANNE , BUSS SANDRA L. 
Published: February 2008

SummaryA method is described for obtaining from plants partially purified preparations of mycoplasma‐like organisms (MLO) which are suitable for use as immunogens for polyclonal or monoclonal antibody production, and as antigens for directly coating ELISA plates. Using this method a mouse monoclonal antibody to primula yellows MLO was prepared, and its characteristics compared with those of primula yellows polyclonal antibodies from rabbits and also against polyclonal antibodies made to similar preparations of European aster yellows MLO. No serological distinction was obtained between any of the homologous or heterologous combinations of antibody and MLO preparation using ELISA, fluorescence microscopy with FITC‐labelled antibodies, or immunoprobes of western blots of partially purified MLO preparations. By contrast, there were no cross‐reactions between the primula or aster yellows antibodies or MLO preparations and preparations of clover phyllody or tomato big bud MLOs or their respective polyclonal antibodies. The primula yellows MLO monoclonal and polyclonal antibodies, and also the European aster yellows MLO polyclonal antibodies, all appeared to recognize only a single major antigen of approximate M, = 22 400 daltons. Some possible explanations for the apparent specificity of the polyclinic antisera for a single antigen, and the relevance to MLO preparation procedures are discussed.
The phosphorus budget of a field‐grown strawberry (Fragaria x ananassa cv. Hapil) crop: evidence for a mycorrhizal contribution
Authors: DUNNE M. J. , FITTER A. H. 
Published: February 2008

SummaryThe phosphorus content of a field‐grown strawberry crop was monitored over one growing season and the allocation of P to different plant parts determined. In the early part of the season, leaves were the major sink for P and this was partly supplied by redistribution from rhizomes. Once flowers were initiated, these became the major sink and their P requirement was satisfied by new uptake. The calculated rates of P inflow to the roots in this phase of growth were so large that it was necessary to postulate not only that P uptake was assisted by mycorrhizas, but that the whole root system, including the old, brown roots, was active. The implications of this conclusion for concepts of vesicular‐arbuscular mycorrhizal function under field conditions are discussed.
The influence of cypermethrin and oxydemeton‐methyl treatment on Lygus damage in young Scots pine seedlings
Authors: HOLOPAINEN J. K. 
Published: February 2008

SummaryLaboratory experiments were carried out to evaluate the efficiency of two insecticides, cypermethrin and oxydemeton‐methyl, in controlling the nymphs and adults of Lygus bugs and the resulting damage caused by these bugs to small pine seedlings. Both insecticides significantly increased the mortality of bugs on the seedlings compared with bug mortality on untreated controls. Mortality of bugs was higher in the oxydemeton‐methyl treatment than in the cypermethrin treatment. The occurrence of seedlings with multiple leaders and the number of leader shoots per seedling were significantly decreased in insecticide‐treated seedlings. Mean number of leader shoots was significantly higher in seedlings treated with oxydemeton‐methyl than in seedlings treated with cypermethrin after a 24‐h exposure to nymphal instars of Lygus. The mortality of the pine seedlings was very low but significantly decreased in insecticidal treatments. Factors affecting the effects of different insecticides on bug mortality and their efficiency in controlling the multiple‐leadering phenomenon are discussed.
The effects of desiccation and root diffusates from potato and mustard on eggs of the white potato cyst nematode Globodera pallida
Authors: FORREST J. M. S. 
Published: February 2008

SummaryFollowing exposures to potato root diftusate of between 6 and 12 h, desiccation killed a proportion of juveniles in eggs of G. pallida and affected the hatching behaviour of survivors. In hatching tests of 9 wk duration, more juveniles hatched in the final wk from cysts, which were soahed and dried alternately for 9 wk than from cysts soaked in tap water for the final 2 wk only. Mustard root diffusate prevented eggs previously stimulated by potato root diffusate from hatching, but it did not alleviate the effects of desiccation.
Non‐propagative translocation of velvet tobacco mottle virus in the mirid, Cyrtopeltis nicotianae
Authors: GIBB KAREN S. , RANDLES J. W. 
Published: February 2008

SummaryNymphs of the mirid, Cyrtopeltis nicotianae became infective when injected with velvet tobacco mottle virus (VTMoV). Injections of amounts between 1 and 154 ng into the haemocoele induced 2/60 to infect test plants and these two nymphs contained 50 and 63 ng of virus respectively. Injection of amounts between 15 and 2400 ng rendered 11/47 nymphs infective. This observation is characteristic of a circulative association. However, there is no evidence that the salivary glands are involved in transmission and the virus is therefore defined as translocating, rather than circulating, in the mirid vector.Mirids which acquired infectivity by feeding lost it between 5 and 9 days after completion of acquisition, and the most rapid loss of infectivity occurred within 2 days. Nine days after acquisition none contained antigen detectable by ELISA, but detectable antigen decreased less rapidly than infectivity, and at all times more mirids contained antigen than were able to transmit. Mirids containing antigen carried between 150 and 3340 ng each. Thus, although VTMoV can be transmitted by its mirid vector following introduction of virus into the body cavity by injection, VTMoV is not propagative. Nor does the presence of virus within the mirid guarantee an ability to transmit.
Deterrent effect of carboxylic acids on cabbage root fly oviposition
Authors: COLE ROSEMARY A. , JONES T. H. , FINCH S. 
Published: February 2008

SummaryIn laboratory experiments, 11 selected carboxylic acids were tested to determine which part of the sinapic acid molecule is responsible for deterring cabbage root fly from laying its eggs on otherwise‐acceptable cauliflower host‐plants. The deterrent effect was only obtained with compounds containing at least one carboxylic group in the molecule. Hence, the aliphatic acids were as deterrent as the aromatic acids to the fly and all the carboxylic acids were as deterrent as sinapic acid, reducing oviposition by > 50%. The inclusion of two carboxylic groups in the molecule, (e.g. phthalic acid and oxalic acid) did not increase the deterrent effect observed with sinapic acid. Some of the long chain fatty acids, with low volatility, low water solubility and thus greater persistence, offer practical opportunities for deterring Delia radicurn from laying its eggs on plants in the field.
Infectibility of some new raspberry cultivars with arabismosaic and raspberry ringspot viruses and further evidence for variation in British isolates of these two nepoviruses
Authors: JONES A. T. , MITCHELL M. J. , BROWN D. J. F. 
Published: February 2008

SummaryIn field trials at sites of an outbreak of arabis mosaic nepovirus (AMV) in England and of raspberry ringspot nepovirus (RRV) in Scotland, the results of exposure of some new raspberry cultivars to natural infection with these viruses showed discrepancies from those obtained in graft inoculation tests using AMV‐Lib and RRV‐S, the Scottish type isolates. In particular, cv. Glen Prosen, which is immune to AMV‐Lib and RRV‐S, was infected with AMV and RRV in the field trials. Studies on these and other field isolates of AMV and RRV showed that they differed from the type isolates in Rubus host range and in symptomatology in herbaceous hosts. However, whereas four isolates of RRV found infecting Rubus were distinguishable by spur formation in gel double‐diffusion serological tests, six AMV isolates were indistinguishable by this method. Immunoelectrophoresis of virus particles did not distinguish the six AMV isolates, but isolates RRV‐MX and RRV‐T were distinguishable from RRV‐S and the English type isolate, RRV‐E. Like the two RRV type isolates, RRV‐MX contained a single electrophoretic component, but it migrated must faster whereas RRV‐T contained two components, one with a migration rate similar to that of RRV‐MX and the other similar to that of the type isolates. Polyacrylamide gel electrophoresis of protein preparations from highly purified virus particles of RRV isolates E, S and MX detected a single polypeptide of estimated mol. wt 54 × 103, 54 × 103 and 50 × 103 respectively but that of isolate T contained two polypeptides of estimated mol. wt 54 × 103 and 50 × 103. These data suggest that RRV‐T is a mixture of two isolates. In laboratory tests the nematode Xiphinema diversicaudatum transmitted four isolates of AMV efficiently whereas two populations of the nematode Longidorus elongatus were less efficient vectors of four RRV isolates. Neither vector species transmitted virus to any of nine raspberry cultivars. The results are discussed in relation to the control of nepoviruses in raspberry and to the biology of these viruses.
Specificity of the effect of sap‐transmissible viruses in increasing the accumulation of luteoviruses in co‐infected plants
Authors: BARKER H. 
Published: February 2008

SummaryThe concentration of potato leafroll luteovirus (PLRV) (c. 1300 ng/g leaf) in singly infected Nicotiana clevelandii plants was increased up to 10‐fold in plants co‐infected with each of several potyviruses, or with narcissus mosaic potexvirus, carrot mottle virus or each of three tobravirus isolates. With the tobraviruses, PLRV concentration was increased equally by co‐infection with either NM‐type isolates (coat protein‐free cultures containing RNA‐1) or M‐type isolates (particle‐producing cultures containing RNA‐1 and RNA‐2). In contrast, the accumulation of PLRV was not substantially affected by co‐infection with either of two nepoviruses, cucumber mosaic cucumovirus, broad bean mottle bromovirus, alfalfa mosaic virus, pea enation mosaic virus or parsnip yellow fleck virus. The specificity of these interactions between PLRV and sap‐transmissible viruses was retained in tests made in Nicotiana benthamiana and when beet western yellows luteovirus was used instead of PLRV.
A model of the effect of codling moth granulosis virus on Cydia pomonella
Authors: BRAIN P. , GLEN D. M. 
Published: February 2008

SummaryA model was developed based on an initial ingestion phase, followed by a period of virus multiplication and host death, to describe the effects of codling moth granulosis virus (CpGV) concentration and time from initial infection on the percentage of codling moth larvae (Cydia pornonella) dying from virus infection in the laboratory. With modification, this model also described the effect of CpGV concentration on the reduction of damage to fruit by C. pomonella larvae in the field. In both cases, the effect of CpGV increased with the l/10th power of virus concentration.LT50 (time to death of 50% of larvae) was inversely related to virus concentration in the laboratory.The model predicts the threshold concentration for death of larvae, as well as LD50(C50 and LD90(C 90,) for all ages of larvae.The model also predicts that if the majority of larvae entered through the sides of apple fruits, rather than through the calyx or near the stalk (as they probably did in the field), then the efficacy of CpGV in reducing fruit damage would be lowered. This effect of site of entry is especially marked at low virus concentrations.