bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the feeding of Sitona lineatus L. (Coleoptera: Curculionidae) on white clover (Trifolium repens L.) seedlings
Authors: MURRAY P. J. , CLEMENTS R. O. 
Published: February 2008

SummaryMeasurements of feeding damage by sitona weevil (Sitona lineatus L.) adults on differing numbers of seedlings of white clover (Trifolium repens L.) at the first and fourth trifoliate leaf stage were made in the glasshouse at 20°C. S. lineatus consumed more of the trifoliate component of the seedling. Sitona adults caused significant yield reduction at all levels of plant population. Total clover consumption increased with increasing size of sitona population, but consumption per adult weevil was reduced.
Purification and properties of closterovirus‐like particles associated with a whitefly‐transmitted disease of sweet potato
Authors: COHEN J. , FRANCK A. , VETTEN H. J. , LESEMANN D. E. , LOEBENSTEIN G. 
Published: February 2008

SummaryA virus causing sunken veins on ‘Georgia Jet’ sweet potato, and yellow brittle leaves and stunting on Ipomoea setosa, was purified and a specific antiserum was prepared. Flexuous particles with a normal length of 850 nm and a diameter of 12 nm with an open helical structure typical of closteroviruses were observed. The virus particle protein has an apparent mol. wt of c. 34 kD. Double‐stranded RNA isolated from SPSVV‐infected I. setosa and subjected to electrophoresis in agarose consisted of one major band with an estimated Mr of 10.5 kbp and two minor bands with Mr of 9.0 and 5.0 kbp. Fibril‐containing vesicles in phloem cells were observed in ultrathin sections of infected leaf tissues. The virus was transmitted by the whitefly Bemisia tabaci in a semi‐persistent manner and by grafting, but not mechanically. The virus could be transmitted to various Ipomoea species, to Nicotiana clevelandii, N. benthamiana and Amaranthus palmeri. The virus did not react with an antiserum to lettuce infectious yellows virus. Based on particle morphology, serology and symptom expression, the virus appears unique and different from all other reported whitefly‐transmitted closteroviruses. We propose it be named “sweet potato sunken vein virus” (SPSVV).
Evaluation of biological indexing and dsRNA analysis in grapevine virus elimination
Authors: HABILI N. , KRAKE L. R. , BARLASS M. , REZAIAN M. A. 
Published: February 2008

SummaryFragmented shoot apex culture (FSAC) was used to eliminate some diseases caused by viruses and virus‐like agents from 24 varieties of imported grapevines. Each cultivar was examined by biological indexing before and after FSAC. Graft indexing revealed that leaf roll, stem pitting and yellow speckle diseases were common before FSAC. A correlation was observed between the incidence of leafroll disease and the presence of specific dsRNA species which were removed after FSAC. One of these species, an RNA of about one kilobase pair was associated with low yielding Sultana clones. Both biological indexing and dsRNA assay indicated no recurrence of the leafroll disease in material regenerated by FSAC even after 10 years in the field. It is concluded that dsRNA assay may be used as a faster and less expensive method than biological indexing in assessing the success of leafroll elimination by FSAC. The test also provides some information on the genome size of the viruses associated with leafroll disease. Graft indexing indicated that yellow speckle disease was resistant to elimination by FSAC, while stem pitting was removed from some of the vines and the grapevine fleck disease was eliminated from most sources.
Detection of three whitefly‐transmitted geminiviruses occurring in Europe by tests with heterologous monoclonal antibodies
Authors: MACINTOSH S. , ROBINSON D. J. , HARRISON B. D. 
Published: February 2008

SummarySelected monoclonal antibodies (MAbs), prepared to particles of African cassava mosaic or Indian cassava mosaic geminiviruses, detected three geminiviruses that occur in Europe: abutilon mosaic virus in Abutilon pictum ‘Thompsonii’, tobacco leaf curl virus in Lonicera japonica var. aureo‐reticulata and tomato yellow leaf curl virus in Lycopersicon esculentum. All three viruses were detected in indirect ELISA by MAbs SCR 17 and SCR 20 but they were differentiated by their reactions with SCR 18 and SCR 23. Tobacco leaf curl virus was detected only when reducing agents were included in the leaf extraction medium. Inclusion of sodium sulphite slightly improved detection of tomato yellow leaf curl virus but reducing agents were not needed for detection of abutilon mosaic virus.
Transmission of sowbane mosaic virus by Thrips tabaci in the presence and absence of virus‐carrying pollen
Authors: HARDY V. G. , TEAKLE D. S. 
Published: February 2008

SummaryWhen pollen of sowbane mosaic sobemovirus (SoMV)‐infected Chenopodium amaranticolor was dusted onto C. amaranticolor and C. quinoa test seedlings which were then infested with 5–10 adult Thrips tabaci, SoMV was transmitted to 25%C. amaranticolor and 88% of C. quinoa plants. Five hours access of T. tabaci to pollen‐contaminated C. quinoa seedlings was sufficient for SoMV transmission, but 1 h was not. SoMV was also transmitted when T. tabaci was mixed with pollen of C. amaranticolor and then placed on C. quinoa test seedlings. Further, plant‐to‐plant transmission of SoMV occurred in the absence of virus‐carrying pollen when T. tabaci was caged on infected non‐flowering C. amaranticolor or C. quinoa for 1–8 days and then adults transferred to C. quinoa test seedlings. This is the first time that thrips have been shown to be a vector of SoMV, and that a virus outside the ilarvirus group is reported to be transmitted using pollen and thrips.
Subterranean clover mottle sobemovirus: its host range, resistance in subterranean clover and transmission through seed and by grazing animals
Authors: WROTH J. M. , JONES R. A. C. 
Published: February 2008

SummarySubterranean clover mottle sobemovirus (SCMV) was transmitted by manual inoculation of sap to 27 cultivars belonging to three sub‐species of subterranean clover. The virus readily infected systemically all inoculated plants of five susceptible cultivars of ssp. subterraneum. Ten others showed partial resistance as not all infected plants developed systemic infection; cold winter conditions further delayed or prevented systemic movement in four of them. Two cultivars of spp. brachycalycinum and four of spp. yanninicum failed to develop systemic infection following inoculation and were considered highly resistant. Resistance to SCMV in three of the spp. yanninicum was further confirmed by the failure to establish detectable primary infections in most of the inoculated leaves. Moreover, when the four ssp. yanninicum cultivars were graft‐inoculated with SCMV, systemic infection eventually developed in them but the virus concentration was low. SCMV was also transmitted by manual inoculation of sap to a further 23 species of Trifolium, Medicago or Pisum. Three species were non‐hosts, five were infected only in inoculated leaves and 18 others developed systemic infection in some or all plants.SCMV reached very high concentrations and was stable in subterranean clover sap. It was transmitted experimentally between subterranean clover plants by brushing infected leaves against healthy ones and in swards was readily transmitted by the trampling and grazing of sheep, but only poorly by mowing. Seed transmission of SCMV to seedlings of five cultivars of subterranean clover was low (0–0.12%). SCMV was not transmitted by Myzus persicae.
Antimicrobial and insecticidal activities of cashew tree gum exudate
Authors: MARQUES MARIA RITA , ALBUQUERQUE LAURENIA MARIA B. , XAVIER‐FILHO J. 
Published: February 2008

SummaryThe gum exudate of the cashew tree (Anacardium occidentale) was shown to inhibit growth of some fungi and bacteria. The gum also prevented oviposition and reduced the number of surviving adults of the Bruchid Callosobruchus maculatus. The feeding of larvae of the Chrysomelid Crimissa cruralis was also strongly affected by the gum. These results suggest an active role for the gum in the defence mechanisms of the plant.
Inheritance of the external mechanical damage resistance of potato cultivars
Authors: DE M. J. , BRADSHAW J. E. , CALIGARI P. D. S. 
Published: February 2008

SummaryThe examination of nine potato cultivars for external mechanical damage resistance found that tests involving the damage index of Robertson (1970) were reasonably consistent over five years. Progeny testing of eight cultivars in two years, by means of a half diallel with selfs, showed that all of the progeny variation was due to general combining ability and there was no evidence of significant specific combining ability. Ranking of cultivars by damage index was significantly correlated with their ranking by general combining ability from their progenies. The results indicate that the best parents for breeding to improve damage resistance can be predicted using their own damage index.
A review of the biology and control of the vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae)
Authors: MOORHOUSE E. R. , CHARNLEY A. K. , GILLESPIE A. T. 
Published: February 2008

SummaryAt the turn of the century, damage by Otiorhynchus sulcatus was sporadic and limited to small areas. Increasing horticultural intensification and the adoption of husbandry techniques favourable to the weevil, such as the use of polythene mulches, increased its pest status. The development of the early inorganic pesticides reduced the number of serious outbreaks of this pest and weevil control was further improved by the development of the persistent organochlorine insecticides in the 1940's. The banning of a number of the more persistent insecticides over recent years has now left the horticultural industry in a very vulnerable position. O. sulcatus is now a pest on a range of horticultural crops throughout the temperate regions of the world. Infestations are most common in Europe (where it originated) and the USA, and nearly 150 plants species have been identified as potential hosts to O. sulcatus. Damage is most frequently caused by the root feeding larval stage. Populations as low as one larva plant can kill sensitive species such as Cyclamen. Severe damage by the leaf feeding adults is less common, although low levels of damage or contamination by adults may be unacceptable in certain situations. There is one generation a year. Oviposition by the flightless parthenogenetic females occurs over the summer months with oviposition rates of c. 500 and 1200 eggs adult‐1for outdoor and laboratory populations, respectively. O. sulcatus mainly overwinters as larvae, although significant numbers of adults may survive in areas where winter temperatures are not too severe.A number of natural enemies, such as hedgehogs, frogs and predatory beetles, help to maintain O. sulcatus populations at a low level in natural environments, but they are less successful in intensive horticultural systems where persistent chemicals have been heavily relied on to maintain the population below the economic threshold level. Increasing environmental concern is now forcing growers to consider new pest control strategies. Controlled release formulations of non‐persistent products, such as fonofos and chlorpyrifos, have shown potential as control agents for O. sulcatus larvae. Biological control agents, such as insect parasitic nematodes, have been developed commercially and new microbial control agents are in the process of development. Most of the new control products are directed towards control of O. sulcatus larvae. Adult vine weevils are nocturnal and a much more difficult target for the new control agents. It is likely that an integrated approach to pest control will be required to maintain O. sulcatus populations below their economic threshold level.
Feeding behaviour of Aphis craccivora (Koch) on cowpea cultivars with different levels of aphid resistance
Authors: MESFIN T. , THOTTAPPILLY G. , SINGH S. R. 
Published: February 2008

SummaryThe feeding activity of Aphis craccivora (Koch) was monitored on cowpea plants of aphid‐susceptible (Vita 7) and aphid‐resistant (TVu 801) cultivars, using an AC electronic feeding monitoring system. Waveforms corresponding to salivation, phloem ingestion and non‐phloem ingestion were observed. Aphids probing on the resistant cultivar showed a significantly reduced ingestion of phloem sap compared with those aphids which fed on the susceptible cultivar. The insect also made more brief and repeated probes on TVu 801. In addition, the duration of non‐probing activities and non‐phloem ingestion was shorter on the susceptible than on the resistant cultivar.
The use of metabolic profiling in the identification of gall mite (Cecidophyopsis ribis Westw.)‐resistant blackcurrant (Ribes nigrum L.) genotypes
Authors: BRENNAN R. M. , ROBERTSON G. W. , McNICOL J. W. , FYFFE L. , HALL J. E. 
Published: February 2008

SummaryThe terpenoid fractions of bud extracts from blackcurrant genotypes showing resistance or susceptibility to gall mite (Cecidophyopsis ribis) infestation were examined and compared using gas chromatography. By the use of discriminant analysis, and the application of the derived discriminator to the data, resistance status was correctly predicted in 88% of the genotypes sampled. The use of metabolic profiling provides a useful alternative to lengthy field assessments.
Comparative effects of Steinernema feltiae (Nematoda: Steinernematidae) and insecticides on yield and cropping of the mushroom Agaricus bisporus
Authors: GREWAL P. S. , RICHARDSON P. N. , COLLINS G. , EDMONDSON R. N. 
Published: February 2008

SummaryIn a mushroom crop (Agaricus bisporus) affected by a very low level of sciarid fly (Lycoriella auripila) infestation, the effects of an indigenous isolate of insect‐parasitic nematode (Steinernema feltiae) and of two commonly used insecticides (diazinon and diflubenzuron) were studied. When compared with untreated plots, nematodes applied to the casing had no adverse effects on mushroom yields whereas insecticides decreased yields. At a rate of 3 × 106 infective juveniles per tray (surface area = 0.56 m2), S. feltiae elicited increases of 28.5% and 19% in the mean total numbers and weights of mushrooms respectively. Treatment only with diflubenzuron resulted in 14.6% and 6% reductions in mean total numbers and weights of mushrooms, respectively; treatment with both diazinon and diflubenzuron caused 18.5% and 9.4% losses.Application of nematodes generally reduced the mean weight per mushroom whereas insecticides increased it; nematodes delayed the onset of mushroom production (first flush) whereas diflubenzuron delayed the third and fourth flushes. Nematode contamination of sporophores was minimal when S. feltiae was applied at casing. Although their numbers declined with time, the nematodes persisted, in the casing layer, throughout the cropping period of seven weeks. It is concluded that yield benefits associated with nematode application can result mainly from nematode effects on A. bisporus and not solely from suppression of a damaging pest population.
The role of refuge areas in the phenology of Rhopalosiphum padi in low rainfall cropping areas of South Australia
Authors: BARRO PAUL J. DE. , MAELZER DEREK A. , WALLWORK HUGH 
Published: February 2008

SummaryExtensive surveys of possible aphid habitats in South Australia indicated that irrigated perennial grass pastures in the Mount Lofty Ranges and Lower Murray Valley were summer refuges for Rhopalosiphum padi (L.) (Hemiptera: Aphididae). Large numbers of aphids build up in these pastures each year during autumn (April and May) with numbers peaking in May. The size of the May peak was related to the number of aphids surviving the summer. The proportions of alates were highest in May and August/September. Both peaks coincided with a photoperiod of between 11.2 and 11.5 h, and partial correlations suggested that aphid density, photoperiod and temperature were all significant determinants of alate production.
Low‐temperature scanning electron microscopy of hyphal colonisation of Chenopodium quinoa during fermentation with Rhizopus oligosporus
Authors: PENALOZA W. , HEDGER J. N. , THOMAS B. J. 
Published: February 2008

SummaryIn a study of tempe made by fermenting quinoa (Chenopodium quinoa Willd.) with Rhizopus oligosporus Saito, the interaction between the substrate and the fungus varied according to the raw material used. Low‐temperature scanning electron microscopy confirmed that hyphal infiltration in quinoa was normally limited by the seed coat, but a massive penetration was found in fragments of quinoa where the testa was broken. This finding has implications for the texture and quality of tempe fermentation of grains and pulses.
Inheritance of antagonistic properties and lytic enzyme activities in sexual crosses of Talaromyces flavus
Authors: MADI LEA , KATAN TALMA , HENIS YIGAL 
Published: February 2008

SummaryTwo wild‐type strains and three benomyl‐resistant mutants of the antagonistic ascomycete Talaromyces flavus were crossed in six combinations, two of which yielded hybrid cleistothecia. Parental strains and their ascospore progenies varied in several traits considered to play an important role in the capacity to control soilborne fungal pathogens: extracellular activities of glucose oxidase and cell‐wall degrading enzymes, antibiosis towards Verticillium dahliae, and parasitism and biocontrol of Sclerotium rolfsii. A non‐Mendelian quantitative mode of inheritance was found for β‐1, 3‐glucanase and chitinase activities but only the latter exhibited a normal frequency distribution. Some of the progenies exhibited higher glucanase and chitinase activities than those found in the parental strains. Progeny analysis for chitinase, glucanase, cellulase, and glucose oxidase activities revealed no genetic association between any two of these enzymes. Antibiosis was correlated with glucose‐oxidase activity in one cross, but not in the other. The ability to reduce bean root rot caused by S. rolfsii was correlated with mycoparasitic activity against S. rolfsii sclerotia in one cross, but not in the other. One out of the 20 progenies tested was able to reduce bean root rot more effectively than its parent strains, thus demonstrating the feasibility of improving a biocontrol agent by conventional breeding.
The distribution and spread of hop latent viroid within two commercial plantings of hop (Humulus lupulus)
Authors: ADAMS A. N. , MORTON A. , BARBARA D. J. , RIDOUT M. S. 
Published: February 2008

SummaryThe distribution and spread of hop latent viroid (HLVd) in two adjacent plantings of the hop cultivars Omega and Wye Challenger have been studied for three seasons. The planting of cv. Omega was heavily infected at the start of the survey and spread was rapid; the density of infection was lower in the planting of cv. Wye Challenger and spread was much slower. It is not known whether the difference in rate of spread was a varietal effect or because of the higher density of infection in the Omega planting. The distribution of known infections in 1991 suggests that plant‐to‐adjacent‐plant spread, either by contact or on tools, does occur. However, the overall distribution of infection and the occurrence of new infections not adjacent to existing ones, suggests that this is not the only means of transmission; whether a vector is involved is not known.
The association between species of Trichodorus and Paratrichodorus vector nematodes and serotypes of tobacco rattle tobravirus
Authors: PLOEG ANTOON T. , BROWN DEREK J. F. , ROBINSON DAVID J. 
Published: February 2008

SummaryVirus transmission bait tests with single trichodorid nematodes from England, the Netherlands, Scotland or Sweden showed that a substantial degree of specificity occurs between trichodorid vector species and tobravirus serotypes. This specificity was more apparent with associations between Paratrichodorus vector species and tobravirus serotypes than with those between Trichodorus species and tobravirus serotypes. P. pachydermus transmitted PRN‐serotype tobacco rattle virus (TRV) isolates, P. teres ORE‐serotype isolates and P. anemones TRV isolates which did not react with any of the antisera used, but which could be distinguished from all other isolates by their symptomatology in Chenopodium test plants. T. viruliferus, T. primitivus and T. cylindricus transmitted RQ‐serotype isolates and the latter species also transmitted TRV isolates reacting with TCB2 and pea early‐browning SP5‐antisera. Several TRV isolates transmitted by T. cylindricus failed to react with any of the antisera used.
Responses of some Asian and European barley cultivars to UK and Chinese isolates of soil‐borne barley mosaic viruses
Authors: JIANPING CHEN , ADAMS M. J. , FENGTAI ZHU , CEN SHI , HE CHEN 
Published: February 2008

SummaryIn field plots at Yancheng, Jiangsu, China, a range of European and Asian barley cultivars was grown in soil from three sites in China infested with barley yellow mosaic virus (BaYMV). Most of the cultivars resistant to the common European strain of BaYMV were susceptible to the Chinese isolates but cv. Energy remained disease‐free. Barley mild mosaic virus (BaMMV) was also detected in one of these soils but affected only one Chinese cultivar and not those susceptible to BaMMV in Europe. This is the first report of BaMMV in China.Inoculation experiments confirmed the different cultivar response to UK and Chinese isolates of BaYMV and showed that resistance was to the virus and not to the vector. A range of Chinese cultivars selected for resistance to BaYMV were also resistant to a UK isolate of BaMMV.
Weeds as hosts of Mycocentrospora acerina
Authors: HERMANSEN ARNE 
Published: February 2008

SummaryWeeds were collected from carrot fields and some other sites at 27 localities in seven counties in Norway during August and September of 1986 and 1987. Leaf and petiole lesions were microscopically examined for Mycocentrospora acerina. Viola arvensis and Viola tricolor were commonly observed with the pathogen. The fungus was also registered on Fumaria officinalis, Galium aparine, Matricaria inodora, Matricaria matricarioides, Ranunculus repens, Senecio vulgaris and Stachys palustris. In inoculation experiments in the greenhouse, M. acerina infected carrot leaves and 13 of 16 species of weeds. The symptoms on the various susceptible plants showed some variation, but were essentially of the same pattern. The investigation indicates that weeds are common hosts of M. acerina. A list of 23 host weed species is given.