bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of the predatory mite Anystis baccarum (Prostigmata: Anystidae) on apple rust mite Aculus schlechtendali (Prostigmata: Eriophyidae) populations in Northern Ireland Bramley orchards
Authors: CUTHBERTSON A G S , BELL A C , MURCHIE A K 
Published: July 2006

Summary Anystis baccarum is a common predatory mite in Northern Ireland Bramley orchards. To determine its effect on Aculus schlechtendali populations, sticky traps and sprays of demeton‐S‐methyl were used to exclude A. baccarum from branches. Out of four trials, exclusion of A. baccarum by sticky traps alone resulted in significantly greater numbers of A. schlechtendali in one trial. In the other trials where A. schlechtendali numbers were lower, there was either no effect, or possible evidence of fewer A. schlechtendali. The combination of demeton‐S‐methyl treatments and sticky traps to exclude A. baccarum resulted in significantly more A. schlechtendali in two trials out of three in 1998. It seems likely that this resulted from the dual effects of stimulation of A. schlechtendali reproduction by the acaricide and the absence of predation by A. baccarum, because acaricide treatment alone in 1999 resulted in significant reductions in A. schlechtendali numbers at the end of the season. This effect could have resulted from A. baccarum re‐invading the treatment branches after the effects of the acaricide had worn off. It is recommended that growers are encouraged to conserve A. baccarum within their orchards.
Breeding cereals for Mediterranean conditions: ecophysiological clues for biotechnology application
Authors: ARAUS J L , BORT J , STEDUTO P , VILLEGAS D , ROYO C 
Published: July 2006

SummaryWater stress is the main environmental factor limiting cereal yield in Mediterranean environments. For particular regions, such as the Mediterranean basin, the agroecological conditions are expected to get worse. In response to this challenge attempts are being made to improve crop yield through farm‐ management practices and plant breeding efforts. Here we examine traits that may be used as selection criteria for breeding C3 cereal crops with improved yield and stability in Mediterranean conditions. Emphasis is made on the potential implications of defining proper selection traits and target environments when adopting biotechnology approaches in breeding programmes.
Emerging geminivirus problems: A serious threat to crop production
Authors: VARMA ANUPAM , MALATHI V G 
Published: July 2006

SummaryGeminiviruses form the second largest family of plant viruses, the Geminiviridae, represented by four genera: Mastrevirus, Curtovirus, Topocuvirus and Begomovirus. During the last two decades these viruses have emerged as devastating pathogens, particularly in the tropics and subtropics, causing huge economic losses and threatening crop production. Epidemics caused by re‐emerging and newly emerging geminiviruses are becoming frequent even in regions that were earlier free from these viruses. Compared to mastreviruses and curtoviruses, begomoviruses have emerged as more serious problems in a variety of crops, for example, cassava, cotton, grain legumes and vegetables. Major contributory factors for the emergence and spread of new geminivirus diseases are the evolution of variants of the viruses, the appearance of the whitefly ‘B’ biotype and the increase in the vector population. Variability in geminiviruses has arisen through mutations, recombination and pseudorecombination. Genomic recombination in geminiviruses, not only between the variants of the same virus but also between species and even between genera, has resulted in rapid diversification. From the disease point of view, most virulent variants have developed through recombination of viral genomes such as those associated with cassava mosaic, cotton leaf curl, and tomato leaf curl diseases. Heterologous recombinants containing parts of the host genome and/or sequences from satellite‐like molecules associated with monopartite begomoviruses provide unlimited evolutionary opportunities. Human activity has also played an important role in the emergence of serious geminivirus diseases across the globe, like the changes in cropping systems, the introduction of new crops, the movement of infected planting materials and the introduction of host susceptibility genes through the exchange of germplasm.
Inheritance and expression of introduced DNA in transgenic onion plants (Allium cepa)
Authors: EADY COLIN C , READER JILL , DAVIS SHEREE , DALE TRACEY 
Published: July 2006

SummaryTransgenic onion plants (Allium cepa) containing the Cauliflower mosaic virus 35s promoter (CaMV35s) and gfp gene construct encoding the visual green fluorescent reporter protein from pBINm gfp ER and the CaMV35s‐bar gene construct encoding resistance to the herbicide phosphinothricin from pCAMBlA3301 were produced by Agrobacterium‐mediated transformation. These plants weregrown to maturity and selfed in order to determine the expression and inheritance of the transgenes. CaMV35s regulation in onion, as observed by GFP expression, was essentially constitutive, and profiles of regulation were typical of those observed in dicotyledonous plants. Inhibition of CaMV35s regulated gene expression was only observed in one transformant. Both the expression of GFP and tolerance to phosphinothricin appeared to be inherited in a Mendelian fashion. Levels of expression in F1 offspring varied, presumably due to environmental and genetic factors. However, it appeared that copy number did strongly influence GFP protein production and expression. In the majority of plants there were no obvious detrimental phenotypic effects caused by the transgene, the integration event, or Somaclonal variation due to the need to perform tissue culture.
Clonal composition of the peach‐potato aphid Myzus persicae (Homoptera: Aphididae) in France and Scotland: Comparative analysis with IGS fingerprinting and microsatellite markers
Authors: FENTON B , MALLOCH G , NAVAJAS M , HILLIER J , BIRCH A N E 
Published: July 2006

SummaryFourteen colonies of the peach‐potato aphid, Myzus persicae, were taken either from French peach trees or weeds in 2001. Thirty five apomictic parthenogenetic lineages (APLs) were established. Ribosomal DNA intergenic spacer (IGS) fingerprinting was used to characterise these and 28 fingerprints were duly obtained. Those lineages with different fingerprints were considered different genotypes and those with the same fingerprint as the same. The genetic identity of APLs was further tested using four microsatellite loci. APLs that differed by IGS fingerprint had distinct microsatellite allele combinations and those that had the same IGS fingerprint had the same microsatellite allele combinations. The results confirmed that IGS types corresponded to different aphid genotypes. Independent APLs with identical IGS and microsatellite genotype were therefore considered different representatives of the same clone. APLs from M. persicae found on Scottish crops in 1995, 1996 and 2001, as well as a long‐term laboratory line were also examined by the same methods. Their IGS fingerprints were similar or identical suggesting that they all belonged to the same clone. Microsatellite markers also suggested that these lineages were derived from a single clone. Some field lineages exhibited slight modifications to their IGS fingerprints confirming that the IGS evolves more rapidly than these microsatellite alleles. Thus, IGS will continue to provide a useful marker for aphid fieldwork.
A comparative assessment of molecular marker assays (AFLP, RAPD and SSR) for white yam (Dioscorea rotundata) germplasm characterization
Authors: MIGNOUNA H D , ABANG M M , FAGBEMI S A 
Published: July 2006

SummarySeveral DNA‐based marker systems are available for genetic fingerprinting of plants but information on their relative usefulness for yam germplasm characterisation is lacking. The efficiency of RAPD, AFLP and SSR markers for the assessment of genetic relationships, and for cultivar identification and discrimination among 45 West and Central African white yam cultivars belonging to 22 morphotypes/cultivar groups was investigated. Dendrograms were produced based on band pattern scores using the UPGMA method. Results showed that each of the three techniques could unequivocably identify each cultivar, but that techniques differed in the mean number of profiles generated per primer (or primer pair) per cultivar, referred to as genotype index (GI). The order of merit based on this criterion in this study was AFLPs (GI = 2.56), SSRs (GI = 0.39) and RAPDs (GI = 0.35). Yam genotypes classified in the same cultivar group based on morphology were often genetically different, emphasising the need for molecular fingerprinting in yam germplasm characterisation. AFLPs showed the highest efficiency in detecting polymorphism and revealed genetic relationships that most closely reflected morphological classification.
Characterisation of distant Alstrogmeria hybrids: application of highly repetitive DNA sequences from A. ligtu ssp. ligtu
Authors: ZHOU SHUJUN , DE JEU MARJO J , VISSER RICHARD G F , KUIPERS ANJA G J 
Published: July 2006

SummaryClones from a Sau 3A family of eight highly repetitive sequences previously isolated from a genomic DNA library of Alstroemeria ligtu ssp. ligtu were sequenced and found to be highly conserved. A trinucleotide microsatellite repeat [GCA]3−4 was present. A second, unrelated, Sau 3A repeat was also characterised. Southern analysis proved that the isolated repeats were specific for the A. ligtu subspecies and could not be detected in other Chilean or Brazilean Alstroemeria species. As shown by in situ hybridisation, the Sau 3A family and the unrelated Sau 3A repeat co‐localised at distinct sites along most chromosomes of Alstroemeria ligtu ssp. ligtu and Alstroemeria ligtu ssp. simsii. The present set of species‐specific repetitive sequences enables the identification of A. ligtu chromosomes, and thus the tracking of chromosome transmission to interspecific hybrids and their progeny.
Epidemiology of apple proliferation (AP) in northwestern Italy: evaluation of the frequency of AP‐positive psyllids in naturally infected populations of Cacopsylla melanoneura (Homoptera: Psyllidae)
Authors: TEDESCHI ROSEMARIE , VISENTIN CRISTINA , ALMA ALBERTO , BOSCO DOMENICO 
Published: July 2006

SummaryAdults of Cacopsylla melanoneura, vector of the apple proliferation (AP) phytoplasma, were collected every 2 weeks from January until May in 2000 and 2001 by the beating tray method in eight apple orchards of the Aosta Valley (northwestern Italy). Total DNA was extracted from batches of five insects and amplified with the universal phytoplasma primers P1/P7 in direct PCR. A nested PCR assay was then performed on P1/P7 amplicons using the primers fO1/rO1, specific for the AP‐ phytoplasma group. The digestion of fO1/rO1 amplicons with Ssp I restriction endonuclease confirmed that C. melanoneura adults harboured the AP phytoplasma. The data obtained with PCR were used to estimate the proportion of AP‐positive insects in over wintered and offspring adults. Percentages of AP‐positive insects of 3.6% and 0.8% were estimated in 2000 among over wintered and offspring psyllids respectively. In 2001 only the over wintered insects were found infected, with an estimated proportion of 2.8%. The seasonal abundance of the vector was measured using yellow sticky traps. C. melanoneura was always present at a low population level, and the highest density was recorded from mid‐February until mid‐March in both years. The results show that the overwintered population is higher and spends a longer period in apple orchards, suggesting the crucial role of the overwintered adults in vectoring AP.
Redesign of the castorbean plant body plan for optimal combine harvesting
Authors: BALDANZI M , FAMBRINI M , PUGLIESI C 
Published: July 2006

SummaryThe seed oil of castorbean (Ricinus communis, Euphorbiaceae) is highly appreciated in several sectors of the chemical industry. A tropical perennial, with sympodial branching, this plant presents, at the same time, both vegetative shoots and inflorescences, as well as racemes with ripe seeds. This architecture is an obstacle to harvesting the plants using the standard combine harvester which requires, as with any other seed crop, that the plants be dry. One agronomic solution is to spray the plants with desiccants. However, in this paper a genetic solution is suggested, that is, an annual plant. This model is discussed within the present knowledge of plant monocarpic senescence. A mutation that changes the quantity and/or the quality of cambial activity could reduce the secondary growth in castorbean, thus favouring the plants death. Moreover, to stop iterative growth which is at the base of the perennial form of castorbean, a non‐branching model is also proposed. The occurrence of this phenotype in some crops (maize and sunflower) and mutants (tomato, barley, etc.) is examined. Considering apical dominance as the primary mechanism at the base of a non‐branching form, a mutation capable of inducing permanent dormancy of axillary buds is discussed. Both mutation breeding and genetic engineering are suggested as major tools to obtain an annual plant of castorbean.
Nucleotide sequence variation in a small region of the Grapevine fleck virus replicase provides evidence for two sequence variants of the virus
Authors: SHI B J , HABILI N , SYMONS R H 
Published: July 2006

SummaryA region encoding the putative RNA replicase domain of Grapevine fleck virus (GFkV) was amplified from infected grapevine samples using the reverse transcription‐polymerase chain reaction (RT‐PCR). Two different sizes of virus specific PCR products were consistently detected in different grapevine varieties using the same pair of primers. We selected four reference vines and carried out nucleotide sequence analysis. The size of the small product was 353 nucleotides (nt) and that of the large product was 416 nt. Database search showed that both products shared a high sequence homology with GFkV. Sequence variants producing the small size products were named GFkV353, while those giving the large size products were named GFkV416. The small size product shared a higher sequence homology with that of the published GFkV sequence from Italy, which had the same product size of 353 nt, while the large product had a 63 base insertion in that region. This insertion occurred within domain VI of the replicase gene. A survey was carried out for the presence of these two sequence variants in Australia, New Zealand, the USA, South Africa and a number of other countries. In Australia, of 3874 grapevine samples tested by the RT‐PCR assay, 492 (12.7%) contained GFkV353 and 145 (3.7%) contained GFkV416, while only six (0.1%) contained both variants. The sequence homology between these two amplified products and the corresponding regions in related viruses of tymoviruses and marafiviruses is discussed.
Screening Capsicum germplasm for resistance to tomato spotted wilt virus (TSWV)
Authors: CEBOLLA‐CORNEJO J , SOLER S , GOMAR B , SORIA M D , NUEZ F 
Published: July 2006

SummaryResistance conferred by the Tsw locus from Capsicum chinense against Tomato spotted wilt virus (TSWV) has been widely used in breeding programmes. Nevertheless, this resistance depends on inoculation conditions, and isolates able to overcome it have already been detected. In this work 29 accessions of several Capsicum species have been mechanically inoculated with TSWV to identify new sources of resistance. Five accessions showed variable percentages of resistant plants, two of which did not show local lesions on inoculated leaves, suggesting that the response was not mediated through hypersensitivity. Two of these accessions also had a remarkable reduced viral accumulation compared to susceptible control. ECU‐973., a C. chinense accession, showed the best performance against TSWV, with 100% resistant plants. This response was confirmed after mechanical inoculation with three different TSWV isolates. The resistance was maintained when the accession was inoculated with TSWV using a high pressure of viruliferous thrips. These results open new possibilities in the development of a durable resistance to TSWV in pepper.
Development and feeding efficiency of Malacosoma neustrium larvae reared with Quercus spp. leaves
Authors: VERDINELLI M , SANNA‐PASSINO G 
Published: July 2006

SummaryObservations on larval development of Malacosoma neustrium were conducted both in a cork oak stand and in the laboratory by using leaves of different host trees (cork oak, holm oak and downy oak) as food source. Instars were determined using head capsule and frass measurements. In the field the larvae progressed up to the fifth instar before pupating, and the increase in head capsule width followed Dyars Rule with a rate of increase (R.I.) value of 1.74. The same number of instars was determined for the larvae reared with cork oak (R.I. = 1.73) and holm oak (R.I. = 1.70) leaves. The caterpillars reared with downy oak foliage completed larval development in five, six and seven instars and the R.I. values obtained were 1.60, 1.52 and 1.44 respectively. A lower mortality was recorded for the larvae reared on holm oak. Growth and feeding indices were determined for the larvae from the third up to the last instar. The highest leaf consumption was detected for the fifth instar larvae reared on holm oak. For the caterpillars which completed five instars before pupating, the relative consumption rate (RCR) decreased from the third up to the fifth instar: from 4.8 to 1.7 (cork oak), from 7.4 to 3.3 (holm oak) and from 14.3 to 2.1 (downy oak). The relative growth rate (RGR) was highest during the fourth stadium (0.24, 0.27 and 0.33 for larvae reared with cork oak, holm oak and downy oak leaves respectively) and decreased in the fifth instar (0.09, 0.14 and 0.14 for larvae reared with cork oak, holm oak and downy oak leaves respectively), probably because of greater expense of energy due to the approach of maturity. Feeding and growth indices could be useful to define a defoliation prediction model.
Temporal dynamics of tuber formation and related processes in a crossing population of potato (Solanum tuberosum)
Authors: CELIS‐GAMBOA CAROLINA , STRUIK P C , JACOBSEN E , VISSER R G F 
Published: July 2006

SummaryThe chronological relationships between stolon formation, stolon tip swelling, tuber initiation, flowering, senescence, growth and resorption of tubers were studied under field conditions in a diploid population of potato with 238 genotypes, the parental clones and seven tetraploid cultivars. Timing of tuber initiation was not closely related to the timing of stolon formation, flowering and duration of the plant cycle. Tuber initiation very often preceded stolon branching. The number and size distribution of tubers were largely influenced by the degree of stolon branching, the length of the stolon swelling period and tuber resorption. The peak production of stolons and swollen stolon tips largely took place within the flowering period, although in most genotypes, some stolon tip swelling took place until the end of the plant cycle. More information on the general temporal relationships between events related to tuber formation and plant development will contribute to a better understanding of the physiological and genetic basis of the processes leading to the production of harvestable tubers.
Seasonal variations in production and development of leather leaf fern leaves1
Authors: STRANDBERG J O 
Published: July 2006

SummaryProduction and development of leatherleaf fern leaves were studied using containerised plants growing in a shade house. Leaf development was partitioned into seven arbitrary development stages; the time needed for leaves to progress through each developmental stage was used to measure days required to reach maturity. Measurements were made twice each week throughout 1997. Means and variances with in emergence rates of new leaves and time needed for new leaves to pass through six leaf development stages were calculated for 26 14‐day periods throughout the year and compared with degree days, solar radiation, soil temperature, and daylight hours accumulated during the periods. Leaf production rates ranged from 0.15–0.73 leaves day−1 plant−1. The average time from emergence to maturity was 22.6 days. Both leaf production and development rates varied greatly with the seasons, and were strongly associated with the weather variables measured, but significant cyclic rate fluctuations unrelated to weather were also detected. Leaf emergence rates were more strongly related to average soil temperature, whereas leaf development rates to maturity were more strongly related to solar radiation and degree days.
Potato proteins, and other plant proteins, as potential transgenic resistance factors to pollen beetles in oilseed rape
Authors: ÅHMAN INGER , MELANDER MARGARETA 
Published: July 2006

SummaryProteinase inhibitors (PIs), lectin and patatin purified from potato tubers were tested in no‐choice feeding assays with pollen beetle larvae (Meligethes spp.). The idea was to search for resistance factors possible to introduce into oilseed rape (Brassica napus) by genetic engineering. The larval diet was prepared by soaking oilseed rape anthers in protein solutions of known concentrations. Potato lectin was the most potent in that it was the only of these proteins that reduced both larval survival and growth rate, while cysteine, aspartic and metallo PIs and patatin only reduced larval growth rate. Serine PIs had no significant effect on larval performance. Subsequently, the effect of potato lectin was compared to that of lectins from other food or feed crops, resulting in the following mortality‐ based ranking of activity: Con A from jackbean > wheat germ lectin > potato lectin > peanut lectin. In choice tests, larvae did not discriminate between Con A‐ and control‐diets. These results suggest that the effect of Con A on larvae is toxic, not deterrent. Adult response was stronger to Con A than to potato lectin in no‐choice tests, just as it was in larvae. However, adult survival rate and weight was not affected by Con A but the lectin significantly reduced adult feeding as well as oviposition rates. A resistance factor that suppresses adult feeding on flower buds is important for reduced impact of the pollen beetle on the Brassica oilseed crop.
Preparation of total RNA from a very small wheat embryo suitable for differential display
Authors: CHEN YIHUA , WEINING SONG , DAGGARD GRANT 
Published: July 2006

SummaryA simple method was developed for extracting total RNA from a single mature wheat seed embryo, which is very small and hard. Guanidine thiocyanate and chloroform were employed and the grinding of the samples was performed in a microcentrifuge tube with a plastic pestle. A jacket. of liquid nitrogen and simplified procedures were applied to ensure the thorough grinding of the embryo tissue and to minimise the loss of samples. These measures substantially increased the recovery of total RNA in the extraction process. Reliable differential display was successfully achieved with the total RNA after DNase treatment and reverse transcription. This method makes it viable to study gene expression and gene regulation in a single wheat seed embryo. It may also give researchers the ability to analyse mRNAs in tissues or organs which were previously too small for RNA isolation using conventional procedures.