bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some hosts, properties and possible affinities of a labile virus from Hypochoeris radicata (Compositae)
Authors: BRUNT A. A. , STACE‐SMITH R. 
Published: February 2008

SUMMARYHypochoeris mosaic virus (HMV) is common in Hypochoeris radicata (‘cat's ear’) in western Canada. It infected 10 of 53 mechanically inoculated species in five of twelve families, but was not transmitted by aphids or through seed or soil. Sap from infected Nicotiana clevelandii was sometimes infective after dilution to 10‐1 and occasionally 102, after 10 min at 45 but not 50°C, and after 1 but not 2 days at 20°C. Infectivity of crude nucleic acid extracts from infected leaves was rapidly abolished by RNase but not by DNase.Host sap contained very few rod‐shaped particles or particle fragments mostly 21.0–22.5 nm in diameter, and up to 420 nm long but with predominant lengths of 120–140 and 240–260 nm. Many rods in purified virus preparations were less than 240 nm long, and the majority were c. 140 nm or shorter. The particles had a helical substructure with a pitch of 2.58 nm and contained a single type of protein of estimated mol. wt 24.5 × 103.HMV showed no serological relationship to eight morphologically similar viruses (beet necrotic yellow vein, broad bean necrosis, barley stripe mosaic, peanut clump, potato mop‐top, Nicotiana velutina mosaic, wheat soil‐borne mosaic and defective strains of tobacco mosaic). It is probably a hitherto undescribed tobamovirus.
The detection of plum pox virus in Prunus species by enzyme‐linked immunosorbent assay (ELISA)
Authors: ADAMS A. N. 
Published: February 2008

SUMMARYPlum pox virus (PPV) was detected by ELISA throughout the year in extracts of root, bark, fruit, flowers and leaves of Prunus species; extracts from healthy plants gave negligible background reactions. In the summer, ELISA values obtained with extracts from infected leaves were variable but samples extracted at 1:50 (w/v) could have been diluted a further five to 110 times before reaching the limit of detection. Using a single antiserum the virus was detected in several hundred trees, suggesting that there was little antigenic variation.PPV was unevenly distributed in leaves and shoots and commonly occurred in only a few branches of an infected tree although it was frequently present in suckers growing from the roots. Virus was detected in the only three trees known to be infected in random leaf samples taken from 530 1‐yr‐old trees, but some infected trees were missed in samples taken from older trees and from a 7‐yr‐old rootstock hedge. The main practical use of ELISA for PPV is therefore as a sensitive and highly reliable confirmatory test which greatly facilitates control of the disease by the prompt destruction of infected trees.
Studies on mutagenesis and cross‐protection of cauliflower mosaic virus
Authors: TOMLINSON J. A. , SHEPHERD R. J. 
Published: February 2008

SUMMARYThree strains of cauliflower mosaic virus (CaMV) designated NVRS, CM4‐184 and PK caused respectively severe, moderate and mild reactions in turnip cv. Just Right plants and severe, mild and symptomless reactions in Brussels sprout cv. Fasolt plants.Chlorotic local lesions formed consistently in the leaves of young turnip plants when inoculated with each of the virus strains. Lesions were suitable for infectivity assay of crude and purified preparations of the virus.Three variants of the NVRS strain were isolated by single‐lesion transfer after treatment of the virus with nitrous acid (pH 5.0) and two variants were obtained after treating the virus in acetate buffer at the same pH. One of the variants (designated V3) caused symptomless infection in turnip and Brussels sprout plants.In cross‐protection tests, Brussels sprout plants infected symptomlessly with the PK, CM4‐184 or the V3 strains, subsequently resisted infection by the severe NVRS strain.
The effects of dehydration on freezing injury in a range of carrot cultivars
Authors: TUCKER W. G. , COX C. J. 
Published: February 2008

SUMMARYCarrot cultivars given a mild freezing treatment (–2.5°C for 16 h) showed significant differences in the amounts of external and internal ice formed and in the amounts of electrolytes diffusing from broken tissues after thawing. Dehydrating the carrots in vitro up to 9% loss of fresh weight decreased the formation of external ice in all cultivars but decreased internal ice formation only in the Chantenay and Autumn King cvs; internal ice formation in the Amsterdam Forcing cv. was unaffected by up to a 7% loss of fresh weight. Of the cultivars tested, the Chantenay cv. withstood the freezing treatments best and the Amsterdam Forcing cv. the least with the Autumn King cv. intermediate between the two. There was no indication of cold hardiness by a natural adjustment of the water content of the carrots in the field during the winter in any cultivar.
Effects of inoculation with Septoria nodorum on yield components of spring wheat
Authors: WAFFORD J. D. , WHITBREAD R. 
Published: February 2008

SUMMARYSpring wheat, cv. Kolibri, was artificially inoculated with spore suspensions of Septoria nodorum, from the time of full expansion of the third leaf to the end of flowering and the effect on yield components recorded. Most components were reduced by increasing severity of infection and grain weight losses of 56 and 35% were produced on single‐stemmed and tillering plants respectively, by the most severe infection. The effects on components of yield differed considerably between the main stems and the tillers and an increase in grain number on moderately infected tillers partly compensated for reductions in yield on the main stem.
Growth of broad beans infected by Uromyces viciae‐fabae
Authors: WILLIAMS P. F. 
Published: February 2008

SUMMARYThe effect of artificially regulating the level of a rust infection with Uromyces viciae‐fabae (Pers.) Schroet. on the growth and yield of two cultivars of Viciafaba L. (broad beans) was examined in 1973/74.Disease decreased leaf area ratio without increasing net assimilation rate particularly during the stage of ‘pod filling’. Consequently, assimilate supply to developing beans was diminished and the weight of beans per pod and yield of beans per plant decreased.This is unlike the effect of Botrytis fabae Sard, on broad beans which reduces yield by decreasing the number of pods per plant. This suggests that the two leaf spotting pathogens decrease yield in different ways and so may require different approaches to minimise yield losses.
The interaction between mushroom strains and fungicides in the control of dry bubble disease caused by Verticilliumfungicola
Authors: GANDY DOREEN G. , SPENCER D. M. 
Published: February 2008

SUMMARYFive fungicides were compared for control of Verticilliumfungicola on six strains of the cultivated mushroom. The strains showed considerable differences both in their sensitivity to the fungicides and their susceptibility to infection. These factors complicated comparison of the fungicides, but benodanil was less effective than chlorothalonil against V. fungicola.
The use of enzyme‐linked immunosorbent assay to detect, and discriminate between, small iridescent viruses
Authors: KELLY D. C. , EDWARDS MARY‐L. , ROBERTSON J. S. 
Published: February 2008

SUMMARYThe enzyme‐linked immunosorbent assay (ELISA) double antibody method provided an efficient method for detecting iridescent virus (type 22) in purified preparations and extracts of Galleria mellonella larvae; 10 ng of purified virus/ml were detected with confidence. The ELISA method discriminated between the five iridescent viruses tested.
Rapid detection and serotyping of prunus necrotic ringspot virus in perennial crops by enzyme‐linked immunosorbent assay
Authors: BARBARA D. J. , CLARK M. F. , THRESH J. M. , CASPER R. 
Published: February 2008

SUMMARYStrains of prunus necrotic ringspot virus (NRSV) in hop and plum cultivars were rapidly and conveniently detected and serotyped by enzyme‐linked immunosorbent assay. Antisera produced against the G isolate of NRSV from cherry and the Paradise isolate of apple mosaic virus (ApMV) from apple were used concurrently to ensure detection of all serotypes and to differentiate between them. Both NRSV and ApMV serotypes occurred in plum either as single or mixed infections. By contrast, the NRSV serotype was not found in hop, which contained either ApMV or a serotype intermediate between NRSV and ApMV.
A comparison of the rate of drying of four nematode species using a liquid paraffin technique
Authors: WOMERSLEY CHRISTOPHER 
Published: February 2008

SUMMARYA technique of immersion refractometry has been employed to compare the rates at which four species of nematodes lose water during desiccation at 0% r.h. Panagrellus redivivus and Ditylenchus myceliophagus showed little ability to control water loss, although in the latter species coiling helped slow the rate of drying. Ditylenchus dipsaci and Anguina tritici exhibited a much greater degree of control over water loss during desiccation, A. tritici being more successful. D. dipsaci revived from ‘wool’ showed a marked decrease in ability to control water loss when compared with freshly extracted worms. The results obtained have been compared with those from work using interference microscopy, and a critical assessment of the liquid paraffin technique is presented.
Healthier seed potatoes. I. Effects of inoculating stem cutting stocks with Polyscytalum pustulans and Rhizoctonia solani on growth, yield and disease
Authors: HIDE G. A. , BELL F. 
Published: February 2008

SUMMARYPotato seed tubers of seven cultivars derived from stem cuttings in 1965 (healthier seed) were grown in 1969–72 at two sites, one clay with flints soil (Rothamsted) and the other sandy loam soil (Woburn). Inoculating sprouted tubers at planting with Polyscytalum pustulans did not affect the number of stems/plant or total yield but increased stem base and tuber infection. The yields of large tubers (57–83 cm) were increased and small tubers (>57 cm) decreased, indicating a decrease in tuber numbers. Rhizoctonia solani inoculated at planting decreased numbers of stems/plant and yield by up to 14% at Woburn but not at Rothamsted. At both sites, yields of large tubers were increased with cvs Majestic and Record and decreased with Pentland Crown. Stem canker and tuber infection were increased but infection was also prevalent on tubers from non‐inoculated seed at Woburn.When both pathogens were inoculated together yields of large tubers were increased in cvs King Edward, Majestic and Record and decreased in Pentland Crown. Infection of stem bases and tubers was sometimes less than when either pathogen was inoculated singly.
Healthier seed potatoes. II. Effects of sprouting and benomyl treatment of stem cutting and commercial stocks on growth, yield and disease
Authors: HIDE G. A. , BELL F. 
Published: February 2008

SUMMARYPotato seed tubers of seven cultivars derived from stem cuttings in 1965 (healthier seed) were compared with samples from commercial stocks in 1969–72 at two sites, one clay with flints soil (Rothamsted) and the other sandy loam soil (Woburn). Plant emergence, usually slower from non‐sprouted seed, was unaffected by seed source or seed treatment with benomyl. Sprouted healthier seed produced more stems/plant than sprouted commercial seed.Healthier seed yielded 6% (Rothamsted 5%, Woburn 8%) more than commercial when seed was sprouted and 7% (Rothamsted 6%, Woburn 9%) when not sprouted. The increased yields of cvs Record (10% sprouted, 23% not sprouted), Majestic (8% sprouted, 11% not sprouted) and King Edward (5% not sprouted) mostly comprised small ware (44–57 cm) and chats (>44 cm), indicating an increase in tuber numbers. Commercial Pentland Crown seed yielded as much as healthier but the healthier produced less large ware (57–83 cm). Benomyl treatment of commercial seed, especially when not sprouted, and sometimes of healthier seed also decreased tuber size.Infection of stem bases and tuber eyes by Polyscytalum pustulans was less from healthier than commercial seed and was decreased by benomyl. Stem canker (Rhizoctonia solani) was also decreased by benomyl but fungicide treatment of seed did not greatly decrease the high incidence of R. solani hyphae on eyes of tubers at Woburn. Helminthosporium solani, equally prevalent on the produce of commercial and healthier seed, was decreased by benomyl. There was slightly more gangrene (Phoma exigua) on the produce of commercial than healthier seed.
Effects of air temperature on seed growth and maturation in cowpea (Vigna unguiculata)
Authors: ROBERTS E. H. , SUMMERFIELD R. J. , MINCHM F. R. , STEWART KATRINE A. , STEWART W. , NDUNGURU B. J. 
Published: February 2008

SUMMARYThis investigation has attempted to quantify the effects of air temperature on seedgrowth in cowpea independent of phenology and other major ontogenetic changes inthe physiology of the parent plant. Fruits produced in identical positions on the mainstem of plants (which, in three of the four environments tested, were almost identicalin dry weight and morphology at the onset of flowering) were harvested at regularintervals after anthesis. Four day‐night temperature regimes (mean values inparentheses) were investigated: 33‐24 C (283 C); 33‐19 C (256 C); 27‐24 C (254 C) and 27‐19 C (228 C). Overall, the mean dry weight ofindividual seeds contained in the first fruit produced in the coolest regime was morethan double that recorded in the warmest environment, with the two intermediateregimes giving intermediate but similar results to each other. These final weightswere brought about by almost identical durations of the linear phase of increase indry weight (about 9 days) in the three warmer regimes but a longer duration (about 11 days) in the coolest regime, while the rates of increase in dry weight during thisphase were identical in the three cooler regimes (about 13 mg seed‐1 day‐1) butconsiderably less in the warmest environment (about 10 mg seed‐1 day‐1). Attributes of the first formed fruits are compared with ‘average’ fruits in eachenvironment and implications of these data in legume physiology and breeding are discussed.
Viruses occurring in East Africa that are related to peanut mottle virus
Authors: Bock K. R. , Guthrie E. J. , Meredith Gina 
Published: February 2008

SUMMARYViruses occurring in Cassia bicapsularis in Northern Tanzania, in Voandzeia subterranea in north western and eastern Tanzania, and in Phaseolus lunatus in the Kenya highlands, were all serologically related to peanut mottle virus. Their host ranges, and the symptoms they induced in test plants, were very similar, and they differed only in degree of virulence in some host species.The Voandzeia isolate did not infect groundnut, and only the Phaseolus isolate infected two species in the Cucurbitaceae. All the isolates infected Chenopodium amaranticolor, a species which formerly was reported as being immune to peanut mottle and thus considered of diagnostic value.In Africa, variation in peanut mottle virus isolates seems to be associated with host species and ecology, and there is at present no evidence for naturally occurring variants within a host species as occurs in groundnut in America.Three of the four isolates were purified by homogenising together infected leaf tissue, chloroform and 0.5 M sodium citrate buffer containing 1% 2‐mercapto‐ethanol at pH 8, in the proportion 1: 1:2 respectively, and precipitating the virus from the clarified homogenate with 5% w/v polyethylene glycol. When centrifuged in sucrose density gradients such preparations gave a single, bright specific light scat‐tering zone with no haze.
Decreased severity of ryegrass mosaic virus after passage through resistant perennial ryegrass
Authors: WILKINS P. W. 
Published: February 2008

SUMMARYAfter exposure to infection in the field, the proportion of plants showing distinct symptoms of ryegrass mosaic virus (RMV) was less in perennial than in Italian ryegrass. The perennial ryegrass cv. Mascot had a smaller proportion of plants with symptoms than cv. S.23. Far milder symptoms were induced in test plants by RMV from naturally infected perennial ryegrass plots than from Italian ryegrass plots. Within perennial ryegrass, RMV from cv. Mascot caused milder symptoms than that from cv. S.23. Severe RMV isolated from Italian ryegrass cv. Trident (RMVT) became milder after one passage through cv. Mascot, although not as mild as RMV obtained from field plots of cv. Mascot (RMVM).Families from two highly resistant perennial ryegrass clones and two randomly selected clones of cv. S.23 crossed in all possible combinations varied in symptom severity when inoculated with RMVT but not when inoculated with RMVM. Families inoculated with RMVT also yielded virus which varied in the severity of symptoms induced in test plants, families with severe symptoms yielding severer virus. Thus, much of the variation in the resistance of these clones could be attributed to infection with RMV of differing severity. Resistance was controlled by several genes which were mainly additive in their effect.
The relative efficiency of foliar sprays and granular insecticides in control of the jassid Empoasca lybica on eggplant
Authors: Kisha Jennifer S. A. 
Published: February 2008

SUMMARYOmethoate, formothion, monocrotophos and carbaryl were the most effective of a number of insecticides evaluated as foliar sprays for the control of Empoasca lybica on eggplant. The duration of insecticidal activity was about 20 days, three sprays being required during the season.Disulfoton, carbofuran and terbufos granules applied to the soil at the rate of 0.1 g a.i./plant c. 1 month after transplanting gave control of jassid throughout the season and a significant yield response.
The effects of herbicides, applied atone and in sequence, on the control of wild‐oats (Avena fatua) and broad‐leaved weeds, and on yield of winter wheat
Authors: Wilson B. J. , Cussans G. W. 
Published: February 2008

SUMMARYExperiments were done to examine the effects of controlling wild‐oats and autumn‐germinating broad‐leaved weeds in winter wheat, early in winter or late in spring. The herbicides used were barban (winter), chlortoluron or isoproturon (winter), and benzoylprop‐ethyl, at the recommended doses and at half doses. Sequential treatments of two herbicides at half doses were also examined. All treatments were given a routine broad‐leaved herbicide treatment in spring.Yields of wheat were influenced more by the time of weed removal than by the degree of control achieved. Grain yields at three sites with dense autumn broad‐leaved weed populations were greatest following the use of chlortoluron or isoproturon. At three other sites with moderate to dense wild‐oat populations (60 to 240 plants/m1), the use of barban at the crop three‐leaf stage gave larger yields than benzoylprop‐ethyl in late spring at the early stem elongation stage of the crop. Seed formation from surviving A. fatua was similar with both wild‐oat herbicides. The treatment which reduced seed production of A. fatua and maintained crop yield most consistently was barban followed by benzoylprop‐ethyl, each at half the normal recommended dose.
Broomrape (Orobanche) seed germination inhibitors from plant roots
Authors: Whitney P. J. 
Published: February 2008

SUMMARYTwo species (tomato and cucumber) which are not hosts to Orobanche crenata but which are hosts to other species of Orobanche not only failed to produce the compound required to trigger O. crenata to germinate but produced germination inhibitors which stopped germination even in the presence of a suitable stimulant. This suggested the possibility of using germination inhibitors to control at least some species of Orobanche. The question whether host species produce inhibitors as well as stimulants has not however been resolved.
Studies on plant growth‐regulating substances. LIV. Factors affecting the production of active growth substances from structurally related amines in plants
Authors: Price R. , Wain R. L. 
Published: February 2008

SUMMARYA diamine oxidase enzyme has been isolated from pea epicotyls and purified. The in vitro rates at which a number of amines, structurally related to plant growth substances, are oxidised by this enzyme have been measured. These rates when considered together with the growth regulating activity of the acid ultimately produced, enable an assessment of the activity of the amine as a hormone‐type herbicide to be made.
The restoration of male fertility in F1 wheat hybrids
Authors: Done A. A. , Whittington W. J. 
Published: February 2008

SUMMARYThe yield of F1 wheat hybrids is often limited by reduced male fertility. Improvement depends upon selecting male and female parents capable of allowing good fertility ‘restoration’ in the F1 hybrids. Assessment of restoring potential in growth rooms was difficult because fertility was much lower than in field grown plants. In the field, two experiments showed differences between parent lines but also that the fertilities of the F1 hybrids were site‐specific, and that this factor might be considered during further selection. Variation between reciprocal crosses, possibly due to cytoplasmic differences, rendered a proposed test for the early assessment of fertility restoration capacity amongst potential male‐sterile lines to be of doubtful value with present stocks.
Pre‐harvest germination in male‐sterile wheats
Authors: Done A.A. , Whittingtion W. J. 
Published: February 2008

SUMMARYF1 hybrid grain borne on cytoplasmic male‐sterile (A line) parents germinated (sprouted) before maturity but grain set on male‐fertile analogues (B lines) of the A lines did not. Sprouting may involve varied with the pollinator and with the A lines although their ranking order varied between experiments. Unsprouted grain harvested from A lines subsequently germinated more rapidly than that from the B lines.
The early stages of mildew colony development on susceptible oats
Authors: CARVER T. L. W. , CARR A. J. H. 
Published: February 2008

SUMMARYThe chronology of primary infection by Erysiphe graminis f. sp. avenae on detached leaves of a susceptible host, and growth patterns of the primary haustorium and secondary hyphae, proved similar to those of wheat and barley mildew found by other workers. The timing of formation and subsequent growth of the primary haustorium was not affected by the light regime, but the formation of subsequent haustoria was highly synchronous under an alternating dark/light cycle, and far less so under continuous illumination. Five days after inoculation almost twice as many secondary and tertiary haustoria were formed per colony under the dark/light treatment than under continuous light.Because of the synchronous formation of haustoria subsequent to the primary, haustoria selected at random from leaves of susceptible host cultivars showed a bimodal distribution in length, the less well developed tertiary haustoria being distinguished from earlier formed primary and secondary haustoria. There was also a significant positive correlation between length and the number of digitate processes/haustorium. The energy required to produce one secondary haustorium was calculated to be equivalent to that required to produce approximately 4–7 hyphal cells.
A bacteriophage specific to race 2 of the cherry strain of Pseudomonas morsprunorum
Authors: PERSLEY G. J. , CROSSE J. E. 
Published: February 2008

SUMMARYThe isolation and characterisation of a bacteriophage specific to the recently described race 2 of the cherry strain of Pseudomonas morsprunorum in England is described. The phage was subsequently used in a survey of P. morsprunorum races in commercial orchards and on the cherry cultivars Napoleon and Roundel at East Mailing Research Station.