bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uptake of the herbicide [14C] 2,4‐D iso‐octyl in the vapour phase by tomato and lettuce plants and some effects on growth and phytotoxicity
Authors: BREEZE V. G. , van RENSBURG E. 
Published: February 2008

SummaryTomato and lettuce plants were exposed to vapour of the herbicide [14C‐phenyl] 2,4‐D iso‐octyl at concentrations in the range 0–450 pg litre‐1 for periods of 6, 24 and 72 h in separate experiments using a flowing‐air system. The rate of uptake, as indicated by plant content of radiolabel, was both linear with respect to the vapour concentration and independent of the duration of exposure. The uptake rate of tomato was greater than that of lettuce at any given vapour concentration. Uptake by the apical leaves of lettuce was higher than by the older leaves expressed on an area basis; tomato showed no effect of leaf position. Visible symptoms of phytotoxicity were shown by both species 40 days after exposure to the highest doses. Advantages of using the low‐volatile ester (iso‐octyl) of 2,4‐D to reduce vapour drift damage are discussed in terms of plant uptake.
An assessment of somaclonal variation in linseed (Linum usitatissimum)
Authors: MARSHALL G. , COURDURIES P. 
Published: February 2008

SummarySomaclonal lines of linseed from the parent cultivar Norlin were produced from a callus‐based in oitro regeneration system (the R0 generation). In field trials conducted over two seasons, 47 R1 (plants produced from the R0 generation) and 20 R2 somaclonal lines (plants produced from the R1 generation) were compared to the parent cultivar Norlin for quantitative characters. Irrespective of the genotype, traits in R1's and R2's were assessed on the basis of regression analysis as showing heritabilities of between 28% and 64%. Generally, the somaclonal variation assessed during these early generations revealed some detrimental traits, e.g. lower seed yield than the parent (control) cultivar and reduced 1000 seed weights, but a few lines were identified which had early or late flowering dates, improved seed yield and increased 1000 seed weights. It is concluded that somaclonal variation could be of value as an adjunct to classical breeding.
The response of potatoes (Solunum tuberosum L.) to salinity: plant growth and tuber yields in the arid desert of Israel
Authors: LEVY D. 
Published: February 2008

SummaryThe response of potato cultivars to water salinity was studied under field conditions in sandy loessial soil in the arid desert of Southern Israel. The potatoes were drip‐irrigated with water of three different salinities: water commonly used for irrigation (1.0–1.4 dS m‐1); saline water from a local well (6.1–6.9 dS m‐1); and a mixture of the two (3.84.3 dS m‐1). Salinity retarded plant emergence, enhanced haulm senescence and reduced growth of both haulms and tubers. Increasing the salinity progressively reduced tuber yields. Application of the saline water well after plant establishment (Expt A) decreased tuber yields by 615% and 22–31% in the intermediate and the high salinities, respectively. When irrigation with saline water was started soon after planting (Expt B), tuber yields were decreased by 0–17% and 21–79% in the intermediate and the high salinities, respectively. When the tubers emerged in salinised soil, tuber yields were decreased by 21–54% and 42–59% in the intermediate and the high salinities, respectively. A differential response of various cultivars to salinity was observed. None of the potato cultivars or clones exhibited exceptional tolerance to severe salinity. The earlier maturing cvs Atica and Désirée were the least susceptible to the moderate salinity imposed throughout the entire growing season; however, no association was noted between maturation time and the response to salinity.
Differences in yield determining processes of groundnut (Arachis hypogaea L.) genotypes in varied drought environments1
Authors: GREENBERG D. C. , WILLIAMS J. H. , NDUNGURU B. J. 
Published: February 2008

SummaryThirty‐six groundnut gentoypes of varied origin were evaluated for their yield, crop growth rates (C), and partitioning to reproductive sinks (p) in three trials. In the trials irrigation and sowing date were used to vary the amount of water available either throughout the crops' life, or through the grain filling phase. Genotype performance across the five environments for these attributes showed that although differences in C existed, differences in the stability of the partitioning were the dominant attribute of genotypes adapted to the drought prone Sahelian region. Data suggested that these differences were more attributable to tolerance to temperature and/or humidity than water stress. Over all treatments canopy temperatures relative to air (CATD) were strongly correlated with the C observed, but not so with yield; and differences between genotypes in the relationship between C and CATD were not statistically significant.
The effect of modifying plant structure on the yield and maturity of the white lupin Lupinus albus
Authors: MILFORD G. F. J. , DAY J. M. , LEACH J. E. , STEVENSON H. J. , HUYGHE C. , PAPINEAU J. 
Published: February 2008

SummaryExperiments at Rothamsted in the UK and Lusignan in France examined the effect of artificially modifying plant structure on the yield and date of harvest of indeterminate autumn‐sown cultivars of Lupinus albus. Experiments in 1989/90 were done on the cv. Lugel at Rothamsted and those in 1990/91 on the cvs Lugel and Lunoble in both the UK and France.At Rothamsted in 1990, when the summer was warm and dry, the indeterminate cv. Lugel ripened at the end of August and yielded 5.2 t grain/ha. At Lusignan in 1991, where summer weather was also warm and dry, the two unpruned indeterminate cultivars ripened in late July and yielded c. 4.9 t grain/ ha. However, at Rothamsted in 1991, in a season which was predominantly cool and wet, the two indeterminate cultivars were not harvested until late October and yielded only 1.5 and 2.4 t/ha.Plants pruned to a semi‐determinate form consisting of the mainstem plus the 1st‐order branches yielded approximately the same as the unpruned inde‐terminates at Rothamsted and slightly less than the indeterminates at Lusignan. The semi‐determinates ripened 10 days earlier than the indeterminates at Rothamsted in 1990 and Lusignan in 1991, and 6 weeks earlier in the UK in 1991.Epigonal plants with only a mainstem inflorescence, ripened even earlier than the semi‐determinates but, without branch inflorescences, produced less yield and had poorer yield stability. Where disease was not a factor, as at Rothamsted in 1990 and Lusignan in 1991, epigonal plants ripened 3 weeks earlier than the indeterminates and yielded between 1.6 and 2.6 t/ha. When the pruned epigonal plants were badly infested with Pleiochaeta, as at Rothamsted in 1991, they yielded less than 0.4 t/ha.It is concluded that indeterminate genotypes of L. albus are well adapted to the climatic conditions of Lusignan but lack yield stability further north. For the cooler northern regions of Europe, an autumn‐sown, florally‐determinate genotype with one order of branching would produce adequate yield and have an acceptably early harvest date and yield stability. Such a genotype would have agricultural and economic value as a new protein break crop with a low requirement for nitrogen fertiliser.
Glucosinolate changes in developing pods of single and double low varieties of autumn‐sown oilseed rape (B. napus)
Authors: BILSBORROW P E. , EVANS E. J. , MURRAY F. , ZHAO F. J. 
Published: February 2008

SummarySingle and double low varieties of oilseed rape were grown in the 1987/88 and 1988/89 seasons to study changes in the concentrations of total and individual glucosinolates within pods during development. Total glucosinolate concentration in seeds of all varieties increased during development when expressed on a fresh weight basis. The levels of the major alkenyl glucosinolates present in the seed; 2–hydroxy‐3–butenyl, 3–butenyl and 4–pentenyl had been reduced in the transition from single to double low varieties. The major indole glucosinolates in the seed, 4–hydroxy‐3–indolylmethyl and 3–indolylmethyl were present in the same amounts in single and double low varieties but in the latter represented a greater proportion of the total seed glucosinolate content. A decline in the total glucosinolate concentration in the pod walls with time together with the analogous profile of individual glucosinolates in the seeds and pod walls suggests that the pod wall is a major site of seed glucosinolate synthesis. Other plant parts may also have an important role to play in provision of intact glucosinolates or precursors to the pod walls for glucosinolate biosynthesis.
The influence of black bean aphid, Aphis fabae Scop., and its honeydew on the photosynthesis of sugar beet
Authors: HUREJ MICHAL , WERF WOPKE VAN DER 
Published: February 2008

SummaryThe effect of black bean aphids on the photosynthesis of sugar beet plants was studied under glasshouse and field conditions. The presence of up to several hundred aphids per leaf had no significant effect on CO2 exchange rates over a range of light intensities between complete darkness and light saturation. Artificially prepared honeydew, sprayed onto leaves in the same amounts and composition as was found on severely aphid‐infested plants, covered 30% of the stomata on the upper epidermis but did not significantly alter the rate of photosynthesis of these leaves in the light or the rate of respiration in the dark. The stomata on the lower epidermis were uncovered and functional. High pressure liquid chromatography of aphid‐produced honeydew detected 20 different amino‐acids. Three amino‐acids, aspartic acid, glutamic acid and gluta‐mine, made up the bulk of the amino‐acid weight in the honeydew produced on young plants, up till the 8 leaf‐stage. In the 10 to 12 leaf‐stage, several different amino‐acids occurred in substantial amounts. The amino‐acids to sugars ratio of the honeydew produced by the aphids decreased strongly as the sugar beet plants aged: from 1:6 in plants with 3 or 4 leaves to 1:25 in plants having 10 to 12 leaves.
The selective use of floral resources by the hoverfly Episyrphus balteatus (Diptera: Syrphidae) on farmland
Authors: COWGILL S. E. , SOTHERTON N. W. , WRATTEN S. D. 
Published: February 2008

SummaryThe use of flowers of non‐crop plants by the syrphid Episyrphus balteatus in margins of cereal fields was assessed quantitatively. G‐tests and the ‘C’ index of Murdoch (1969) were used to compare the use and abundance of twenty‐seven plant species by adult flies from June to August in the UK. The flowers of several plant species were used selectively by hoverflies throughout the season while the relative importance of others changed with date. The prospects for managing the field‐margin flora to enhance biocontrol by hoverflies is discussed.
The effect of silver and other metal ions on the in vitro growth of root‐rotting Phytophthora and other fungal species
Authors: SLADE S. J. , PEGG G. F. 
Published: February 2008

SummaryA range of metal ions and the oxoanion WO42‐were toxic to zoospores of Phytophthora nicotianae parasitica in the order: Ag+ > Cu++ > WO42‐> Ni+ > Co++ > Zn+. The LD50 for Ag+, 0.11 μM (11.4 ppb), compared with 1.84 μm (117 ppb) for Cu++. Silver was similarly toxic to a range of pathogens including Pythium aphanidermatum, Thielaviopsis basicola and Fusarium oxy‐sporum f.spp. Most zoospores of Phytophthora spp. were killed by Ag+ in the range 46–460 nM (5–50 ppb), bursting at the higher concentrations. A small sub‐population of most propagules exhibited greater tolerance to silver than the whole. In 0.93 μM (100 ppb) Ag+ 1.4% of P. nicotianae parasitica zoospores survived but were all killed at 500 ppb. A population of P. cryptogea (1.9%) surviving 0.47 μm (50 ppb) were killed at 0.93 μM (100 ppb). Zoospore cysts and germlings showed the same sensitivity to silver. Oospores were mostly killed over the range 0.23–0.93 μm (25–100 ppb) Ag+, some surviving up to the lethal concentration of 9.26 μM (1000 ppb). Mycelium of P. cryptogea was generally less sensitive, with some growth occurring at 9.26 μm (100 ppb). Zoosporangiogenesis was unaffected over the range 0.47–4.65 μm (50–500 ppb). Toxicity increased with increased pH over the range 5.0–6.5.Ionic silver was lost from solution during a microscope slide bioassay by binding to the glass surface. In the presence of chloride ions, colloidal AgCl formed which was equally toxic to P. cryptogea. Silver and AgCl were further lost from solution by colloidal agglomeration ‐ Ostwald ripening ‐ and by AgCl adsorption to glass. Silver, < 90 nM (10 ppb) Ag+ as AgNO3 and particles of silver chloride were both strongly attractive to zoospores of P. cryptogea. Spores burst or failed to germinate on entering lethal concentrations. The results are discussed in the context of the use of silver salts to control Phytophthora root‐rot pathogens and the importance of ion availability in in vitro toxicity assays.
Improved detection of iris severe mosaic virus in secondarily‐infected iris bulbs
Authors: VLUGT CORNELIA I. M. VAN DER , DERKS A. F. L. M. , BOONEKAMP P. M. , GOLDBACH R. W. 
Published: February 2008

SummaryThe influence of wounding and high‐temperature treatment on the detection of iris severe mosaic virus (ISMV) in secondarily ISMV‐infected iris bulbs was studied. Wounding of the bulbs just after lifting, followed by storage for 3 wk at 17°C or 20°C, increased the detectability of ISMV to 100% reliability. High‐temperature treatment and consecutive storage at 17°C induced a similar improvement of detection. It is concluded that a certain degree of stress, such as wounding or high‐temperature treatment, ultimately leads to an increase in viral antigens and thus to improvement of detection. It is hypothesised that the virus titre increases by the altered metabolism during the repair reactions as a response to stress applied to the bulbs.
Resistance to potato leafroll luteovirus can be greatly improved by combining two independent types of heritable resistance
Authors: SOLOMON‐BLACKBURN R. M. , BARKER H. 
Published: February 2008

SummaryTwelve potato clones were exposed to infection by aphids with potato leafroll luteovirus (PLRV) in three field trials in order to assess their resistance to infection. Up to 92% of the plants of some clones became infected, although other clones were relatively resistant to infection and one clone remained virus‐free in all three trials. The resistance of the same 12 clones to PLRV multiplication was assessed in glasshouse‐grown plant: lants were graft‐inoculated and their daughter tubers were used to grow plants with secondary infection. High concentrations of PLRV were found in some clones (c. 1700 ng/g leaf) while in others much less virus accumulated (as little as 60 ng/g leaf). However, clones in which little virus accumulated were not necessarily those which were most resistant to infection in the field, and there was no association between the two types of resistance. Nevertheless, both types of resistance were found in some clones. The clone G8107(1), which remained virus‐free in all the field exposure trials, was also the most resistant to PLRV multiplication. The combination of these two types of resistance in cultivars should help to eliminate the spread of PLRV in crops.
The effect of pre‐harvest pruning on the quality of cassava starch
Authors: ASAOKA M. , BLANSHARD J. M. V. , RICKARD J. E. 
Published: February 2008

SummaryTwo cassava cultivars CMC 40 and MPer 245 were grown at the Centro Internacional de Agricultura Tropicale (CIAT) in Colombia. Specimens were pruned by the removal of aerial growth 4 weeks prior to harvest and starch granules were isolated from the roots of pruned and control plants after harvest. The glassiness and hardness of cooked roots from the pruned plants showed an increase of 60–70% and 40–60% respectively compared with the controls. Although there was some reduction in the size of the starch granules derived from the pruned roots as compared with the control, pruning had negligible effects upon X‐ray crystallinity, amylose/amylopectin contents, the elution patterns of the isoamylase debranched starch, the susceptibility of the granules to enzyme digestion, their swelling power and solubility, the temperature and enthalpy of gelatinisation and their behaviour in the Rapid Visco Analyser. Minor differences were observed when pruned and control samples were examined in the Brabender amylograph.
Effect of meteorological variates on persistence of primary conidia and capilliconidia of Erynia radicans (Zygomycotin: ntomophthorales) under natural conditions
Authors: UZIEL AVIVA , SHTIENBERG D. 
Published: February 2008

SummaryPersistence of conidia of an isolate of Erynia radicans (Syn. Zoophthora radicans) was investigated in relation to the meteorological conditions which occurred during autumn‐winter of 1990–91 in the coastal plain in Israel. Capilljconidia shielded from the sun, placed on the abaxial surface of leaves of Plumeria acuminata, persisted for 24 h to at least 120 h. Exposed capilliconidia, placed on the adaxial surface of the same leaves, died within 24 h. Almost all the primary conidia shielded from the sun (placed on the abaxial surface of the same leaves) died within a single day. Conidial viability was expressed in subsequent germination on an agar medium.Capilliconidial persistence was closely related to the daily air temperatures, expressed as cumulative day‐degrees. Differences in relative humidity had no substantial effect on capilliconidial mortality. At daytime temperatures of ≤ 20°C, mortality after 24 h incubation was lowest (≤ 34%) and the persistence duration, longest (at least 120 h). Increases in daytime temperature up to 24°C for a few hours increased mortality (37–57% after 24 h incubation) and shortened the persistence duration (72–120 h). Exposure to 24–29°C during daytime greatly increased mortality (65–58% after 24 h) and further shortened the persistence duration (24–48 h). Daytime temperatures of > 29°C were lethal to all capilliconidia within 24 h. Temperature had a profound effect on capilliconidial persistence also under controlled environmental conditions. The significance of capiliiconidial persistence is discussed in relation to activity of the fungus in its natural environment.
Chickpea chlorotic dwarf virus, a new leafhopper‐transmitted geminivirus of chickpea in India1
Authors: HORN N. M. , REDDY S. V. , ROBERTS I. M. , REDDY D. V. R. 
Published: February 2008

SummaryA disease of chickpea in India, characterised by chlorosis, severe stunting and phloem browning, was shown to be caused by a geminivirus. This virus was transmitted by the leafhopper Orosius orientalis from chickpea to chickpea and several other plant species. A method for purification of this virus was devised and a polyclonal antiserum produced. The majority of the purified particles were geminate. The size of the coat protein was shown to be 32 kD and the nucleic acid was shown to be circular ssDNA of 2900 nucleotides. By immunosorbent electron microscopy this virus was shown to be unrelated to the leafhopper‐transmitted geminiviruses known to infect dicotyledons such as beet curly top, bean summer death and tobacco yellow dwarf viruses. On the basis of particle morphology, leafhopper transmission, host range and serology this virus was considered to be a new, hitherto undescribed, geminivirus and was named chickpea chlorotic dwarf virus.
Improved detection of potato leafroll virus in dormant potato tubers and microtubers by the polymerase chain reaction and ELISA
Authors: SPIEGEL SARA , MARTIN R. R. 
Published: February 2008

SummaryThe polymerase chain reaction (PCR) method was reliably used for detection of potato leafroll virus (PLRV) RNA in dormant tubers from field‐grown plants and in vitro‐propagated microtubers. A simple RNA extraction from tuber and microtuber tissue allowed reverse transcription and PCR amplification of viral sequences. It was also demonstrated that ELISA could be used reliably for detection of PLRV in crude sap extracts of dormant microtubers produced in vitro but not in tubers from field‐grown plants.
Preferential grazing of five varieties of spring barley by wild rabbits (Oryctolagus cuniculus)
Authors: BELL A. C. , WATSON S. 
Published: February 2008

SummaryAssessment of grazing damage to five varieties of spring barley (Hordeum vulgare L.) by wild rabbits in an enclosed site revealed varietal differences. The variety Atem was consistently least grazed and Triumph most grazed by rabbits. When variety effects were removed from the analysis significant negative correlations were observed between plant height and stem damage. Differences in sugar content of varieties did not fully explain varietal selection by grazing rabbits.
Aspects of insecticide resistance in the melon and cotton aphid, Aphis gossypii (Hemiptera: Aphididae)
Authors: FURK C , HINES C M 
Published: February 2008

SummaryStrains of the aphid Aphis gossypii, taken from cucumber in UK glasshouses were tested for resistance to pirimicarb, diazinon and heptenophos. Compared to a susceptible strain, resistance factors to diazinon of up to 659 were found in populations collected between 1987 and 1989. Compared to the same susceptible strain, diazinon‐resistant populations also showed a reduced response to heptenophos. All field populations tested against pirimicarb were resistant. Host plant preference tests showed that all strains (including stock cultures) tested could readily breed on cotton. However strains originally collected from chrysanthemum did not transfer to cucumber and likewise strains from cucumber would not colonise chrysanthemum. Polyacrylamide gel electrophoresis of four of the aphid strains showed differences in migration rates and intensity of staining of esterase bands. Intensity of staining was correlated with the degree of diazinon resistance.
The distribution of hop latent viroid within plants of Humulus lupulus and attempts to obtain viroid‐free plants
Authors: MORTON A , BARBARA D J , ADAMS A N 
Published: February 2008

SummaryThe detectability of hop latent viroid (HLVd) was investigated in field‐grown hop (Humulus lupulus L.; an herbaceous perennial in which all the aerial parts die at the onset of winter) plants, using dot‐blot hybridisation. The viroid was readily detected in all aerial tissues in the second half of the growing season but it could not be detected very early in the season. Between early‐ and mid‐season, HLVd was first detected at the base of the new stems and then apparently spread up them as they grew but only became detectable near the tips of the shoots at mid‐season, approximately at the time most elongation growth ended and flowering began. Petioles were the most convenient tissues to test, being easy to collect and, relative to leaf lamina tissue, low in inhibitors. Both dot‐blot and in situ hybridisation failed to detect HLVd in shoot tips taken from plants grown at two ‘low’ temperatures (10°C and 15°C). Failure to produce any viroid‐free plants by in vitro culture from such tips suggested that they did contain viroid but at levels too low to detect by either method. Lower temperatures and smaller explants are now being investigated as means of producing viroid‐free plants.
Occurrence of fungally transmitted wheat mosaic viruses in China
Authors: JIANPING CHEN 
Published: February 2008

SummaryA soil‐borne mosaic disease of winter wheat in Sichuan, Shaanxi, Hubei and Henan provinces was associated with infection by a virus with filamentous particles and that in Shandong, Anhui, Jiangsu and Zhejiang provinces by co‐infection with this virus and soil‐borne wheat mosaic virus. The virus with filamentous particles was identified serologically, by particle sizes, cytopathology and the molecular weights of the coat protein and the two RNA species to be either wheat spindle streak mosaic virus (WSSMV) or wheat yellow mosaic virus. These viruses are probably isolates of the same virus and the name WSSMV is preferred. In baiting tests using infested soil, the dilution endpoints for detecting WSSMV were 1/625‐1/15625, and for the fungus vector, Polymyxa graminis, 1/3125‐1/15625.