bluuebunny/crossref_metadata_2025_split huggingface dataset:
The expression of a baculovirus‐derived chitinase gene increased resistance of tobacco cultivars to brown spot (Alternaria alternata)
Authors: SHI J , THOMAS C J , KING L A , HAWES C R , POSSEE R D , EDWARDS M L , PALLETT D , COOPER J I 
Published: July 2006

SummaryThe Autographa californica multiple nucleopolyhedrovirus (AcMNPV) chitinase gene coding region was amplified using the polymerase chain reaction, inserted into a plasmid (pROK‐2) and replicated in Escherichia coli XL1–blue. The recombinant plasmid was mobilised into Agrobacterium tumefaciens LBA 4404 and inoculated into tobacco leaf discs. The presence of the expressed chitinase in foliar tissue of kanamycin‐resistant plantlets of three Nicotiana tabacum cultivars (CF80, K326 and Xanthi‐nc) was inferred using immunoblotting, and enzyme activity was confirmed using a fluorometric assay. Confocal laser scanning microscopy with immunofluorescent staining of foliar sections from N. tabacum Xanthi‐nc expressing the viral chitinase indicated that the enzyme was restricted to the vascular tissue. Heliothis virescens larvae fed on leaf tissue expressing chitinase were not impaired either in their development to pupation or in their feeding behaviour, in comparision with their counterparts that had consumed similar amounts of untransformed tobacco leaf tissue. By contrast, when tobacco leaves were mechanically inoculated with Alternaria alternata, very few brown spots were observed at inoculation sites in chitinase‐expressing tissue, whereas large and spreading lesions formed in untransformed tobacco tissue. Of all lines that were transformed, as determined by kanamycin resistance, 59% had fewer symptoms of disease (smaller disease indices) than those for untransformed controls.
Importance of spittle bugs, Locris rubens (Erichson) and Poophilus costalis (Walker) on sorghum in West and Central Africa, with emphasis on Nigeria
Authors: AJAYI O , OBOITE F A 
Published: July 2006

Summary Locris rubens (Erichson) (Cercopidae: Homoptera) and Poophilus costalis (Walker) (Aphrophoridae: Homoptera) are endemic pests of sorghum (Sorghum bicolor (L.) Moench) in Nigeria and some other countries in West and Central Africa. Other hosts are maize, pearl millet, rice, sugarcane, and grasses. On sorghum, L. rubens lays eggs in the epidermis of the leaf sheath. There are five nymphal instars and development from egg to adult takes about 33 days. Both species of spittle bugs feed on all growth stages and all parts of sorghum, including the panicle. Feeding symptoms include yellow leaf blotching. Severe infestations often kill young leaves and plants. Under artificial infestation in cages, the severity of damage and associated symptoms as well as grain yield loss increased with an increase in the population density of spittle bugs. Infestation by 15 pairs of adult L. rubens
Resistance of roses to pathotypes of Diplocarpon rosae
Authors: YOKOYA K , KANDASAMY K I , WALKER S , MANDEGARAN Z , ROBERTS A V 
Published: July 2006

SummaryColonies of Diplocarpon rosae derived from single conidia were isolated on malt extract agar, multiplied (at 23°C) and stored (at −20°C) on surface‐sterilised leaf discs of a universally susceptible rose, ‘Frensham’. The resistance of 16 species and cultivars of Rosa to different isolates of D. rosae was assessed using surface‐sterilised leaf discs. Four pathotypes of D. rosae were distinguished on the basis of host range. One species and one hybrid were resistant to all pathotypes. Two species and two cultivars were susceptible to all pathotypes. Four species and six cultivars were interpreted as having vertical resistance because they were strongly resistant to some but not all pathotypes. Only species and hybrids of the section Cinnamomeae were resistant to the pathotype identified as CW1 whereas only roses of other origins were resistant to the pathotype DA2.
Incidence and pathology of common viruses of nerine in Tasmania
Authors: LIMBATH D P , BLANCHFIELD A L , WILSON C R 
Published: July 2006

SummaryThis is the first study of the incidence of common viruses within bulb stocks of nerine in Australia. Five viruses were frequently found within commercial stocks but were never associated with obvious viral symptom expression in the field. This study found cucumber mosaic virus (CMV) infections of Nerine flexuosa, and nerine virus Y (NeVY) infections of N. flexuosa, N. bowdenii and N. fothergilli which we believe to be new host records. Virus incidence varied with virus species, host species, and sample site but did not vary within the same bulb stocks over a 2 yr period. Incidence of the major viruses appeared to correlate with the efficiency of transfer from mother bulb to offsets, suggesting that virus status in Tasmania may be largely determined by the incidence of viruses within original planting material and by subsequent vegetative spread.No effect of the most frequent virus infections was found on the efficiency of flowering, flower quality, and dormant bulb fresh weight in N. flexuosa and N. fothergilli with the exception of a small (16.8%), but economically unimportant decrease in scape length of N. flexuosa co‐infected with NeLV and NeVY. It is concluded that current virus infections in nerine in Tasmania pose little commercial significance to the developing cut flower industry, however discovery of NeYSV in one sample of Lycoris aurea warrants monitoring to ensure that spread of this important pathogen does not occur.
Evaluation under long‐day conditions of 4x‐2x progenies from crosses between potato cultivars and haploid Tuberosum‐Solanum chacoense hybrids
Authors: BUSO J A , BOITEUX L S , PELOQUIN S J 
Published: July 2006

SummaryTwelve 4x families (obtained from a sub‐set of crosses between seven 4x‐potato cultivars and three 2x haploid Tuberosum‐Solanum chacoense hybrids) were evaluated at Hancock, Wisconsin (USA). The 4x‐parents were elite cultivars selected for adaptation in three continents (Europe, South America, and North America). The 2x male clones were able to produce 2n‐pollen grains by a mechanism akin to first‐division restitution with crossover (FDR‐CO). The estimation of the degree of heterosis for total tuber yield (TTY) was obtained by comparing the field performance of the progenies with their respective 2x and 4x parents. Haulm maturity (HM) and general tuber appearance (GTA) were also evaluated. For TTY, the 4x‐2x families (as a group) outyielded both the 4x and 2x parental groups by 10.6% and 42.5%, respectively. In addition, 5 out of 12 families outyielded their corresponding 4x‐parents. These best five families outyielded the group of 4x‐parents by 40.6%. A considerable variability was observed for HM but, in general, the families were later maturing than the 4x cultivars. The identification of 4x‐2x families with GTA within the range of the 4x commercial cultivars was another important observation. An overall lack of parent‐offspring correlation was detected indicating that performance of the parents per se cannot provide a reliable prediction about the performance of the families. Therefore, progeny testing would be an imperative step for selection of parental clones at both ploidy levels. Our study indicated that haploid Tuberosum‐S. chacoense hybrids are able to generate heterotic 4x‐2x families for TTY in combination with good GTA. These results reinforce the view that selection of superior clones for the Northern Hemisphere can be feasible using germplasm with ∼25% genomic contribution of this wild South American species.
Community‐scale seedbank response to less intense rotation and reduced herbicide input at three sites
Authors: SQUIRE G R , RODGER S , WRIGHT G 
Published: July 2006

SummarySpecies diversity and abundance in weed seedbanks were measured at the beginning, and after 3 and 6 yr of the TALISMAN experiment at ADAS Boxworth, Drayton and High Mowthorpe. Fifty species were distinguished in the seedbanks of treatments comprising winter and spring rotations and full and reduced herbicide input. After 6 yr, the number of seedbank species in the main treatments ranged from 11 in the most intense to 26 in the least intense management. Principal co‐ordinate analysis showed that the seedbank community diverged over time between sites and additionally between the two rotation treatments at Boxworth. Only four species were common to all sites but community‐scale descriptors indicated that the change in seedbanks following reduced inputs had common features at the three sites. First, species‐area relations showed a greater relative increase in number of taxa at a plot scale than in the site as a whole, indicating lower inputs encouraged the common weeds more than rare species. Second, both the mean and the standard deviation of the species‐abundance distribution at 6 yr increased in response to reduced inputs. As a result, the number of species slightly more than doubled as herbicide units were reduced from four to one while the total number of seeds increased by two orders of magnitude. Some causes of seedbank change were identified: spring‐germinating species tended to increase when spring cultivation was common in the rotation, while some competitive weeds had a relatively low abundance when they were targeted by herbicide. The results are discussed in relation to optimising the various functions of the seedbank.
Comparison of the changes in mushroom (Agaricus bisporus) compost during windrow and bunker stages of phase I and II
Authors: SHARMA H S S , LYONS G , CHAMBERS J 
Published: July 2006

SummaryThe changes in thermophilic fungi and biochemical characteristics, during windrow and bunker stages of phase I and phase II composts, were compared in this investigation. Composts prepared by the two phase I systems differed in a number of key parameters including mean straw length, population of Scytalidium thermophilum, dry matter, conductivity, nitrogen dry matter, ammonia, fibre content and ash. S. thermophilum populations in phase I composts were significantly higher in windrow compared to bunker‐composted materials as a result of the larger high temperature (65‐80°C) core in bunker treatment, which inhibited microbial activity. Assessment of the composts for loss of matter during composting has revealed that the bunker system can conserve fresh matter better than the windrow production system, possibly due to lower microbial activities during bunker composting. The productivity of the phase II composts prepared from windrow and bunker systems was compared in trials using commercial growers.
A thermal time model for predicting time to aerial shoot elongation in Variegated Solomon's Seal
Authors: YEH D M , LIN Y R , ATHERTON J G 
Published: July 2006

SummaryAerial shoot development in Variegated Solomon's Seal (Polygonatum odoratum‘Variegatum’) was studied under warm (mean 18°C) conditions after dormant rhizomes had been stored at a range of temperatures. After chilling at 0.8–5.5°C for 21–77 days, all rhizomes produced elongated aerial shoots, with mean lengths from 33 cm to 44 cm. Exposure of rhizomes to 15°C or 20°C for 21–77 days resulted in 17% to 50% of buds emerging as shoots, but these either aborted or failed to extend beyond a rosette. The earliest aerial shoot elongation was observed after 7–13 days at 18°C in rhizomes that had been chilled at 0.8–2°C treatments for 59–72 days. The base, optimum and maximum temperatures during pre‐planting storage for subsequent aerial shoot elongation were derived respectively as −1.5°C, 1.9°C and 15.8°C. A thermal time of storage was calculated from these cardinal temperatures and the rate of progress to normal aerial shoot clongation was shown to increase linearly with increasing thermal time to c. 150°Cd. The thermal time procedure for predicting time to aerial shoot elongation constructed from growth room/chamber data was validated using rhizomes that had been exposed to varying temperatures in shadehouse conditions during the winter in Taiwan.
The impact of dimethoate on the spatial distribution of beneficial arthropods in winter wheat
Authors: HOLLAND J M , WINDER L , PERRY J N 
Published: July 2006

SummaryThe within‐field spatial distribution of beneficial arthropods was assessed using two‐dimensional grids of pitfall traps and suction sampling across two winter wheat fields of 4 and 16 ha, before and after an application of dimethoate. An unsprayed 6 m wide buffer zone was left around half the edge of the larger field. Arthropod numbers fluctuated to varying extents prior to spraying. Two species of Carabidae (Pterostichus madidusandP. melanarius), Linyphiidae, Lycosidae andAphidiusspp. (Braconidae) all showed their greatest reduction after spraying. For five carabid taxa,Tachyporusspp. (Staphylinidae) and Collembola the decline in numbers following spraying was no greater than any reduction found during the pre‐spraying period. Within field spatial distributions of three arthropod groups were analysed using SADIE.P. madidus, present in patches across the centre of both fields prior to spraying, was removed by dimethoate and by 34 days after spraying had recovered most at the field edges. Linyphiidae were evenly distributed across both fields prior to spraying. Their numbers were reduced considerably by dimethoate and they did not recover to pre‐spray levels. However, where recovery occurred this was across the centre of both fields indicating their potential to reinvade whole fields.Aphidiusspecies were also evenly distributed across both fields prior to spraying, but did not recover after spraying. Some, but not all arthropods survived within the unsprayed buffer zone and there was some indication that reinvasion of the mid‐field was more extensive where this was present. The importance of field margins with respect to insecticide treatments is discussed.
Effectiveness of resistance genes to the large raspberry aphid, Amphorophora idaei Börner, in different raspberry (Rubus idaeus L.) genotypes and under different environmental conditions
Authors: JONES A T , McGAVIN W J , BIRCH A N E 
Published: July 2006

SummaryThe introduction into commerce of raspberry cultivars with major gene resistance to the large raspberry aphid, Amphorophora idaei, an important pest and virus vector on red raspberry in Europe, has been very effective both in decreasing pest numbers and greatly restricting infection with the viruses it transmits. However, biotypes of the aphid able to overcome these genes have developed in the field in recent years. Additionally, in field and laboratory tests, the response to aphid biotypes and recognised aphid strains of certain raspberry cultivars, such as Glen Prosen and Delight, differ markedly despite the fact that they are reputed to contain the same A. idaei‐resistance gene, A1. In attempts to understand the reasons for this difference in response, analysis was made of the segregation of progeny seedlings from crosses between A. idaei‐resistant and ‐susceptible cultivars to two recognised strains of the aphid. These studies showed that, as expected, cv. Autumn Bliss contained the A. idaei‐resistance gene, A10, and cvs Delight and Glen Prosen each contained the A. idaei‐resistance gene, A1. When progeny seedlings were assayed in a heated glasshouse as young plants and in an unheated Tygan house as 1 m tall plants, the segregation ratios for resistance and susceptibility to A. idaei were largely unchanged. However, when the resistance of individual progeny plants was assessed, c. 37% of the putative gene A1‐containing progeny and 9–23% of the putative gene A10‐containing progeny, behaved differently in these two environments. Experiments involving an A. idaei‐resistant and ‐susceptible parent cultivar showed that shading plants increased their susceptibility to A. idaei colonisation. Whilst this shading effect has implications for experimentally detecting A. idaei‐resistant progeny in segregating raspberry seedlings, it does not explain the difference in field resistance to A. idaei of cvs Delight and Glen Prosen. Such differences in the field seem best explained by the presence in these cultivars of ‘minor’ genes for A. idaei resistance and/or susceptibility that influences the effectiveness of gene A1.
Spectral filters for the control of Botrytis cinerea
Authors: WEST J S , PEARSON S , HADLEY P , WHELDON A E , DAVIS F J , GILBERT A , HENBEST R G C 
Published: July 2006

SummaryExperiments performed in vitro examined the sporulation of Botrytis cinerea (grey mould) under different spectral distributions. Eighty‐three isolates, taken from plants of primula (Primula vulgaris) at different locations throughout the UK, were incubated in the dark, with visible light only and visible plus near‐ultraviolet (nUV) light. On average, compared to isolates not exposed to nUV, sporulation was increased 54‐fold following illumination with nUV light. No isolates showed complete insensitivity to near ultraviolet. New polyethylene materials with different optical properties were then tested on two typical isolates. A film which removed nUV up to 405 nm, compared to a film with nUV absorption up to 384 nm, resulted in the lowest production of conidia (by 5‐fold). The former film was used to clad horticultural polyethylene tunnels in which crops of P. vulgaris and strawberry were grown for two seasons and the incidence of B. cinerea assessed throughout the growth of the crops. The incidence of infection on the P. vulgaris and strawberries was reduced by c. 50% and c. 26% respectively with the nUV blocking film compared to a standard film. The results are discussed in terms of the potential of spectral filters as a novel means of grey mould control in greenhouse‐produced crops.
Elderberry latent virus: its relationship to Pelargonium ringspot virus and its identification as a distinct member of the genus Carmovirus, family Tombusviridae
Authors: JONES A T , McGAVIN W J , BRUNT A A , PHILLIPS S 
Published: July 2006

SummaryThe properties of Elderberry latent virus (ELV) and Pelargonium ringspot virus (PelRSV) were compared. The viruses were largely indistinguishable in herbaceous host range and symptomatology, particle morphology, sedimentation coefficient and RNA profiles and size. They were also very closely related serologically with SDI differences in agarose gel double‐diffusion tests of 1 to 3. Purified virus particle preparations of each virus contained isometric particles c. 30 nm in diameter that sedimented as a major component with an sO20W of 112–115S. Purified virus particle preparations contained a major and a minor ssRNA species that in polyacrylamide gel electrophoresis (PAGE) had estimated sizes of c. 3.8 kb and c. 1.6 kb respectively. Plants of Chenopodium quinoa infected with ELV or PelRSV each contained three dsRNA species of c. 3.8, 2.6 and 1.8 kbp, although the smallest of these species was not evident in all preparations. Protein from purified virus particle preparations contained a major polypeptide that, in SDS‐PAGE, had an estimated Mr of 40 000 (40K). However, after storage of purified virus particles for 7–10 days, protein preparations from PelRSV particles also contained an additional major polypeptide of estimated Mr of 37 000 that is probably derived by degradation of the 40K protein; this additional component was not observed in freshly prepared preparations of ELV. Neither virus was found to be related serologically to 16 other viruses with isometric particles and similar properties. These data, together with the recent finding by other researchers that the smallest RNA species is a sub‐genomic RNA, suggests that both viruses are members of the genus Carmovirus, and that PelRSV is a minor variant of ELV. However, the taxonomic status of these two viruses is discussed in relation to recent brief reports comparing the nucleotide and amino acid sequences of these two viruses.
Insecticidal activity, mammalian cytotoxicity and mutagenicity of an ethanolic extract from Nerium oleander (Apocynaceae)
Authors: EL‐SHAZLY M M , EL‐ZAYAT E M , HERMERSDÖRFER H 
Published: July 2006

SummaryA bioassay procedures utilising the western‐banded blow fly, Chrysomya albiceps (Diptera‐Calliphoridae) has been used to guide the fractionation of an ethanolic extract from the leaves of Nerium oleander (Apocynaceae). The cardiotonic glycoside, neriifolin: (3‐[(6‐deoxy‐3‐0‐methyl‐α‐L glucopyranosyl) oxy]‐14‐hydroxy‐5 β Card‐20 [22]‐endolide) was crystallised from the insecticidal active fraction of the ethanolic extract. The values of LC50 of the ethanolic extract, active fraction, isolated crystals and authentic neriifolin were 164 ppm, 57 ppm, 35 ppm and 36 ppm, respectively when incorporated into the blow fly diet. A primary test on the cytotoxicity and mutagenicity of the crude extract against non‐target organisms was achieved by determining the cytotoxicity and mutagenicity on a mammalian cell line using different concentrations of the extract (in vitro) through a radioactive thymidine incorporation technique and hypoxanthine phosphoribosyl transferase (HPRT) test, using the Chinese hamster lung fibroblasts (V79‐MZ cell line). Cytotoxicity tests revealed that the LC50 was approximately 200 ppm, and the mutagenicity was very low compared to the standard active mutagen.
Bruising of sugar beet roots and consequential sugar loss: current understanding and research needs
Authors: WILTSHIRE J J J , COBB A H 
Published: July 2006

SummaryBruising of sugar beet roots and the consequential sugar loss do not receive the attention they deserve within the sugar beet industry. Recent harvester tests have indicated that current levels of bruising damage could be decreased with existing technology. There is, however, little understanding of biological factors affecting susceptibility to bruising of sugar beet roots. This paper examines the available information on causes of bruising, the significance of some tissue characteristics, the processes of sugar loss following bruising and agronomic, physiological and biochemical considerations relevant to bruising and the sugar loss that follows. Some research needs are identified in conclusion.
Marker gene expression driven by the maize ubiquitin promoter in transgenic wheat
Authors: ROOKE L , BYRNE D , SALGUEIRO S 
Published: July 2006

SummarySelecting a promoter for driving transgene expression is one of the most important factors to consider in a transformation project. Information about the native regulation of the promoter activity is important, but it is also necessary to consider how that activity will be affected when integrated into the genome of the transformed plants. Study of a promoter performance in individually transformed lines provides useful information in this area. The maize ubiquitin 1 (Ubi‐1) promoter has been widely used to drive constitutive transgene expression in monocotyledonous plants. However, lack of data on its activity in individual transformed wheat lines constitutes a gap in the understanding and predictability of this promoter's performance. In this paper, we began addressing this problem by examining the expression of the marker gene uidA, coding for β‐glucuronidase (GUS), under the control of the maize Ubi‐1 promoter in individual transgenic wheat (Triticum aestivum L.) lines from different wheat varieties. The expression of uidA driven by this promoter depended to a great extent on the specific transformation event. Whilst expression was strong and constitutive in all tissues in some of the lines analysed, there were also transgenic lines in which GUS activity was restricted to only a few tissues. In general the maize Ubi‐1 promoter had strong activity in young, metabolically active tissues and in pollen grains.