bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of the growth of apple pollen tubes by EDTA, surfactants and fungicides
Authors: KÖPCKE D , BAUR P , SCHÖNHERR J 
Published: July 2006

SummaryThe effects of EDTA (ethylene diamine tetraacetic acid), Kresoxim‐methyl, Wettable Sulphur 80 WP and the surfactants Triton X‐100, Triton X‐114, Dehydol TA 5 and Dehydol TA 29 on pollen tube growth of Malus domestica, Borkh. cvs ‘Golden Delicious’ and ‘Mondial Gala’ were determined by image analysis. The ED50 ‐ and ED90 ‐ values (effective doses giving 50% and 90% reduction of growth) of the chemicals, except for the surfactants, were determined.The selected test substances showed an inhibiting effect on pollen tube growth, with Kresoxim‐methyl being the most active. Surfactants are components of pesticides and they also caused inhibition of pollen tube growth but only at application rates more then 10‐fold higher than typically recommended. Pollen of both apple cultivars were almost equally sensitive to the chemicals.
The effect of genetic transformations for pest resistance on foliar solanidine‐based glycoalkaloids of potato (Solatium tuberosuni)
Authors: BIRCH AN E , GEOGHEGAN I E , GRIFFITHS D W , McNICOL J W 
Published: July 2006

SummaryFoliage of potato cv. Desiree was harvested from glasshouse‐cultivated plants of five experimental transgenic lines expressing three different insecticidal proteins (snowdrop lectin, Galanthus nivalis agglutinin (GNA); jackbean lectin, Concanavalin A (Con A), cowpea trypsin inhibitor; (CpTi)), tissue‐cultured control plants and standard control (non‐tissue cultured) plants. The foliage was subdivided into stems, upper, middle and lower leaves and analysed separately by HPLC for the solanidine‐based glycoalkaloids a‐solanine and a‐chaconine. The results demonstrate that one or more stages in the plant transformation process (i.e. insecticidal‐ and marker‐gene insertions, gene expression and tissue culture) resulted in a lower level of leaf glycoalkaloids than that found in either the tissue‐cultured controls or standard controls, based on the selected potato lines transformed for insecticidal protein expression. However, the distribution of glycoalkaloids throughout the plant foliage was unaffected by genetic transformation and tissue culture, with the highest glycoalkaloid levels being observed in the top third of the plant. The importance of investigating unexpected effects of genetic engineering on plant secondary metabolism is discussed from an ecological viewpoint.
Phenological growth stages of olive trees (Olea europaea)
Authors: SANZ‐CORTÉS F , MARTINEZ‐CALVO J , BADENES M L , BLEIHOLDER H , HACK H , LLACER G , MEIER U 
Published: July 2006

SummaryThis paper describes the phenological growth stages of olive trees using the BBCH (Biologische Bundesanstalt, Bundessortenamt, Chemische Industrie) scale. Eight principal growth stages for bud, leaf and shoot development, inflorescence emergence, flowering, fruit development, fruit maturity and senescence and 32 secondary growth stages are described. Advantages of the BBCH scale over other methods are discussed.
Effect of Cercospora zeae‐maydis infested maize residue on progress and spread of grey leaf spot of maize in central Uganda
Authors: ASEA G , BIGIRWA G , ADIPALA E , OWERA SAP , PRATT R C , LIPPS P E 
Published: July 2006

SummaryThe spread of grey leaf spot caused by Cercospora zeae‐maydis from infested maize residue on the soil surface and progress over time were studied under tropical conditions at two locations in central Uganda, Kabanyolo and Namulonge, using a susceptible local cultivar, LP16. Infested maize residue collected the previous season was used as the inoculum source in varying amounts; 80% coverage, 40% coverage and 0% soil coverage were used to simulate no tillage, minimum tillage and maximum tillage with complete burial of residues. In all the seasons, disease spread was adequately described by a power law model, whereas disease progress over time was equally well represented by both Gompertz and logistic models. The time factor was highly significant (P < 0.05) for disease development, indicating both increases in disease intensity over time and change in gradients with time. The amount of infested residue on the soil surface in the maize planting was highly significant (P < 0.05) for slope (b) and intercept (a) of the linearised disease gradient. The gradient parameter (b) based on the average for the four directions from the residue source ranged from −0.96 to −0.08 in the second cropping season of 1999, from −2.16 to −0.01 and from −0.87 to −0.03 in the first and second seasons of 2000, respectively. The distance from the infested residue significantly affected foliar disease, but the direction from the residue inoculum source did not, nor was the distance by direction interaction significant. However, interactions between amount of residue and distance were significant. Percentage leaf area affected by grey leaf spot, the areas under disease progress curves and disease intercepts decreased with distance at both locations, but rate of disease increase (r) was generally constant with distance from residue source at Kabanyolo, but not at Namulonge. The relationship between disease severity and amount of residue cover appeared to be affected by the level of background inoculum. At Kabanyolo, where little background inoculum was present, differences were detected in disease severity parameters between the no‐residue plots and residue plots, whereas at Namulonge, where high background levels existed, there was no effect of residue on disease.
Potato cyst nematodes in England and Wales ‐ occurrence and distribution
Authors: MINNIS S T , HAYDOCK P P J , IBRAHIM S K , GROVE I G , EVANS K , RUSSELL M D 
Published: July 2006

SummaryPotato cyst nematodes (PCN) have been known to occur in the UK for nearly a hundred years. They are the most problematic pests of potatoes and can cause severe yield losses. Previous work has shown the two species, Globodera rostochiensis and G pallida, to be distributed throughout the UK. This paper reports the results of the first structured and statistically unbiased survey undertaken to assess their occurrence and distribution in the potato growing land of England and Wales. The survey showed that PCN were present in 64% of sites sampled. Of the populations found, 67% were G pallida, 8% were G rostochiensis and 25% contained both species. The results show an increase in the incidence of PCN since previous studies were completed and confirm the perceived shift towards G pallida as the predominant species. Of the infestations found, 62% had a population density of less than 10 eggs g−1 soil.
The effect of fungicides, irrigation and plant density on the development of Peronospora sparsa, the cause of downy mildew in rose and blackberry
Authors: O'NEILL T M , PYE D , LOCKE T 
Published: July 2006

SummaryDowny mildew of rose (Rosa spp.) and blackberry (Rubus fructicosus), caused by Peronospora sparsa, can cause significant losses in production. In a series of experiments, fungicides with different modes of action to the commonly used phenylamide‐based products were examined for efficacy on both crops. Cymoxanil + mancozeb + oxadixyl and fluazinam gave good downy mildew control on both rose and blackberry. On outdoor, container‐grown rose, high volume sprays of fosetyl‐aluminium were also effective, but on young micropropagated blackberry plants, application as a drench treatment was better than as a spray. Good control was also achieved on blackberry with chlorothalonil and with metalaxyl in formulation with either thiram or mancozeb. There was no evidence of loss of control with phenylamide fungicides due to resistance. Irrigation regimes were also examined on blackberry and sub‐irrigation of plants in propagation on a sand bed led to significantly lower disease levels than those found where plants had been irrigated by overhead sprinklers. Reducing the density of container‐grown rose plants had a measurable effect on the progress of downy mildew, though this was small and temporary when compared with the effect of fungicide treatment. Fungicide programmes which gave season‐long control of rose downy mildew resulted in significantly improved extension growth.
The circulative pathway of begomoviruses in the whitefly vector Bemisia tabaci— insights from studies with Tomato yellow leaf curl virus
Authors: CZOSNEK HENRYK , GHANIM MIRIAM , GHANIM MURAD 
Published: July 2006

SummaryOur current knowledge concerning the transmission of begomoviruses by the whitefly vector Bemisia tabaci is based mainly on research performed on the Tomato yellow leaf curl virus (TYLCV) complex and on a number of viruses originating from the Old World, such as Tomato leaf curl virus, and from the New World, including Abutilon mosaic virus, Tomato mottle virus, and Squash leaf curl virus. In this review we discuss the characteristics of acquisition, transmission and retention of begomoviruses by the whitefly vector, concentrating on the TYLCV complex, based on both published and recent unpublished data.We describe the cells and organs encountered by begomoviruses in B. tabaci. We show immunolocalisation of TYLCV to the B. tabaci stylet food canal and to the proximal part of the descending midgut, and TYLCV‐specific labelling was also associated with food in the lumen. The microvilli and electron‐dense material in the epithelial cells of the gut wall were also labelled by the anti TYLCV serum, pointing to a possible virus translocation route through the gut wall and to a putative site of long‐term virus storage. We describe the path of begomoviruses in their vector B. tabaci and in the non‐vector whitefly Trialeurodes vaporariorum, and we follow the rate of virus translocation in these insects. We discuss TYLCV transmission between B. tabaci during mating, probably by exchange of haemolymph. We show that following a short acquisition access to infected tomato plants, TYLCV remains associated with the B. tabaci vector for weeks, while the virus is undetectable after a few hours in the non‐vector T. vaporariorum. The implications of the long‐term association of TYLCV with B. tabaci in the light of interactions of the begomovirus with insect receptors are discussed.
Can aspirin help identify leaf proteins active in defence responses?
Authors: PIERPOINT W S 
Published: July 2006

SummaryThe oxidation of arachidonic acid in vertebrate tissues is briefly compared to the oxidation of linolenic acid in plants. Both give rise to bio‐active molecules containing cyclopentane rings, the prostaglandins and jasmonic acid respectively. Both oxidations are inhibited by salicylic acid, aspirin and other non‐steroidal, anti‐inflammatory drugs. Aspirin is known to inhibit the cyclising enzyme, cyclo‐oxygenase in animal tissues. By contrast it is thought to inhibit allene oxide synthase (AOS) rather than the analogous cyclising enzyme in plants. This conclusion is based on studies of an unusual isoform of AOS, and it is suggested that a search should be made for aspirin‐acetylatable proteins in extracts of the leaves of temperate crop plants. The possible reaction of aspirin with the unusual AOS produced by sea corals is briefly considered.
Relationship between potassium fertilisation and nitrate assimilation in leaves and fruits of cucumber (Cucumis sativus) plants
Authors: RUIZ J M , ROMERO L 
Published: July 2006

SummaryThe effect of application of different potassium rates on some parameters of nitrate metabolism and yield in cucumber plants (Cucumis sativus) was studied. All plants were grown under controlled conditions in an experimental greenhouse. The treatments consisted of applications of K+ at three rates in the form of K2SO4 (Kl: 0.075 mg ml−1, K2: 0.15 mg ml−1, and K3: 0.30 mg ml−1). The results showed a positive effect of higher K+ fertilisation (0.30 mg ml−1) on uptake, translocation and reduction of NO3− in leaves compared with the lowest K+ rate. In addition, the higher K+ rates strengthened the translocation of organic nitrogenous compounds (amino acids) towards the fruit, thereby perhaps also enhancing the maximal commercial yield. In conclusion, for improved cucumber cultivation under greenhouse conditions, 0.15 mg ml−1 of K+ gave maximal yield, while the application of 0.30 mg ml−1 increased the metabolism and efficient utilisation of NO3−.
Germination ecology of the weed Parthenium hysterophorus in eastern Ethiopia
Authors: TAMADO T , SCHUTZ W , MILBERG P 
Published: July 2006

SummaryGermination ecology of Parthenium hysterophorus, recently introduced to Ethiopia, was studied in a series of experiments. Viability of the seeds was greater than 50% after 26 months of burial in the soil indicating the potential build‐up of a substantial persistent soil seed bank. A short period of dry storage was sufficient to overcome a light requirement for germination in a minor fraction of the seeds. Likewise, seeds exhumed from burial showed an increase in germination ability in darkness over time, with a weak tendency for seasonal cyclicity in dormancy level at one of two sites. Germination occurred at the mean minimum (10°C) and maximum (25°C) temperatures of the collection sites, as well as over a wide range of fluctuating (12/2°C‐35/25°C) temperatures in light. No germination of P. hysterophorus seeds occurred at osmotic potentials < ‐0.52 MPa (at 27°C), the species being less tolerant to moisture stress than sorghum grains. Most seedlings emerged from shallowly buried (< 0.5 cm) seeds and none from more than 5 cm depth. Naturally dispersed seeds required about 60 days, at a hot lowland site, to start emergence despite the presence of adequate rainfall, and higher number of seedlings emerged in undisturbed plots than in hand hoed plots. These experiments and field observations suggest that there are no obvious climatic conditions that may limit the germination of Parthenium hysterophorus in Ethiopia, but a high moisture requirement of the seeds for germination could be the major factor limiting germination during the dry season.
Biological and molecular characterisation of Prunus necrotic ringspot virus isolates and possible approaches to their phylogenetic typing
Authors: GLASA MIROSLAV , BETINOVÁ EVA , KÚDELA OTAKAR , ŠUBR ZDENO 
Published: July 2006

SummarySeven isolates of Prunus necrotic ringspot virus (PNRSV) originating from Slovakia were subjected to biological tests under glasshouse conditions. Mainly mild symptoms were observed on chip‐budded test cherry rootstocks. The complete sequence for the capsid protein (CP) gene of four isolates was determined. All sequences were 675 nucleotides long and clustered in the largest of four groups delineated by phylogenetic analyses of all so far known PNRSV CP sequences. A set of restriction endonucleases was suggested to differentiate four isolate clusters by restriction enzyme digestion of CP sequences.
Propagation and characterisation of the freezing tolerance of a novel South African ornamental (Cineraria saxifraga)
Authors: BURCHETT S , FULLER M P , DAKIN‐ELLIOT N 
Published: July 2006

SummarySuccessful propagation of Cineraria saxifraga was achieved using apical softwood cuttings and micropropagation protocols. Plants propagated using micropropagation had a multiplication rate eight times that of the original population after 4 wk. Apical cuttings were subjected to a standard conductive freezing test to establish the freezing tolerance of the species. Results showed that cold‐acclimated plants had a 43% increased survival compared to non‐acclimated plants. Using plants established from tissue culture, two further freezing tests were conducted to establish the effects of surface water and container size on the frost resistance of this species. Surface water significantly decreased survival score compared to dry plants. Plants grown in small containers had a significant decrease in plant survival score compared to those grown in large containers.
Abscisic acid added to the nutrient solution induces a water deficit‐like response in Trifolium subterraneum
Authors: XU X , CIFRE J , MEDRANO H 
Published: July 2006

SummaryThe response of subterranean clover (Trifolium subterraneum) to the addition of increasing concentrations of abscisic acid (ABA) in the nutrient solution (10−3, 10−2 and 10−1 mol m−3) was studied under growth room conditions. Six cultivars of contrasting yield capacity were compared.Plants were grown in Hoagland's solution until they had produced at least four fully developed leaves. ABA was then added and its effect on the fresh weight, leaf number and longest root length was determined, 1 day, 4 days, 7 days and 11 days after addition. The addition of ABA caused significant reductions in all the measured growth parameters, as well as a significant decrease in leaf water potential, which was dependent on the ABA concentration. The average growth reduction after 11 days under 10−1 mol m−3 ABA were within previously reported ranges for this crop under drought, in field conditions. The average leaf number, area of a fully developed leaf and the dry weight per plant of the six cultivars decreased by approximately 50%, whereas the root/shoot ratio increased by 80%.The variation and ranking for this treatment resembled closely those obtained for the same cultivars in field experiments. The cvs Clare, Nuba and Seaton Park, showed the best results under both control and ABA treated conditions. The correlation between the response to ABA in nutrient solution and previous water deficit studies raises the possibility of using this approach as an alternative way to quantify the drought sensitivity of subterranean clover cultivars.
Direct plant regeneration from leaf explants of Plumbago species and its genetic fidelity through RAPD markers
Authors: ROUT G R 
Published: July 2006

Abstract In vitro plant regeneration was achieved from leaf explants of Plumbago rosea and Plumbago zeylanica on Murashige & Skoog (1962) medium supplemented with 1.5 mg litre−1 6‐benzylaminopurine, 0.25 mg litre−1 indole‐3‐acetic acid, 50 mg litre−1 adenine sulfate and 3% (w/v) sucrose. The shoot initials developed within 2–3 wk on the leaf margin as well as from the wounds of the leaf. High frequency shoot‐bud regeneration was achieved on similar medium in subsequent subcultures. The semi‐mature leaves produced more shoot‐buds as compared to the younger leaves. Mature leaves did not show any response for shoot bud initiation. More than 85% of the semi‐mature explants produced shoot‐buds per leaf explant within 4 wk of culture. Shoots rooted easily on medium having half‐strength basal Murashige & Skoog (1962) medium supplemented with 0.25 mg litre−1 indole‐3‐butyric acid and 2% (w/v) sucrose; 84–92% of the in vitro rooted plantlets survived in the greenhouse. The regenerated plantlets appeared morphologically similar to the mother plants. No variation was detected among the regenerated plants by the use of Randomly Amplified Polymorphic DNA (RAPD) markers. This method might be useful for assessing plant improvement programmes.
Physiological changes in soybean (Glycine max) Wuyin9 in response to N and P nutrition
Authors: GAN YINBO , STULEN INEKE , van KEULEN HERMAN , KUIPER PIETER J C 
Published: July 2006

SummaryPhosphorus deficiency is a very common problem in the acid soil of central China. Previous research has shown that starter N and N topdressing at the flowering stage (Rl) increased soybean (Glycine max) yield and N2 fixation (Gan et al, 1997, 2000). However, there is little information available concerning soybean response to P‐fertiliser in soybean production in central China (Gan, 1999). A field experiment was conducted to investigate the response to P (0 kg P ha−1, 22 kg P ha−1, 44 kg P ha−1 before sowing) and N fertiliser application (N1: 0 kg N ha−1, N2: 25 kg N ha−1 before sowing, N3: N2 + 50 kg N ha−1 at the V2 stage and N4: N2 + 50 kg N ha−1 at the R1 stage) on growth, yield and N2 fixation of soybean. Both N and P fertiliser increased growth and seed yield of soybean (P < 0.01). Application of basal P fertiliser at 22 kg P ha−1 or 44 kg P ha−1 increased total N accumulation by 11% and 10% (P < 0.01) and seed yield by 12% and 13% (P < 0.01), respectively, compared to the zero P treatment. Although application of starter N at 25 kg N ha−1 had no positive effect on seed yield at any P level (P > 0.05), an application of a topdressing of 50 kg N ha−1 at the V2 or R1 stage increased total N accumulation by 11% and 14% (P < 0.01) and seed yield by 16% and 21% (P < 0.01), respectively, compared to the zero N treatment.Soybean plants were grown on sterilised Perlite in the greenhouse experiment to study the physiological response to different concentrations of phosphate (P1: 0 mM; P2: 0.05 mM; P3: 0.5 mM; P4:1.0 mN) and nitrate (N1: 0 mM with inoculation, N2: 20 mM with inoculation). The result confirmed that N and P nutrients both had positive effects on growth, nodulation and yield (P < 0.01). The relative importance of growth parameters that contributed to the larger biomass with N and P fertilisation was in decreasing order: (i) total leaf area, (ii) individual leaf area, (iii) shoot/root ratio, (iv) leaf area ratio and (v) specific leaf area. The yield increase at N and P supply was mainly associated with more seeds and a larger pod number per plant, which confirmed the result from the field experiment.
Comparative phytotoxicity of four monoterpenes against Cassia occidentalis
Authors: SINGH H P , BATISH DAIZY R , KAUR S , RAMEZANI H , KOHLI R K 
Published: July 2006

SummaryThe effect of four monoterpenes ‐ citronellol, citronellal, cineole and linalool ‐ on the germination, growth and physiology of Cassia occidentalis was investigated. All four monoterpenes reduced germination of C. occidentalis seeds but to varying extents. Citronellal and linalool completely inhibited germination beyond the concentrations of 55 and 110 μM, respectively, whereas in response to treatment of citronellol no germination was observed beyond 330 μM. Further, the growth of seedlings, measured in terms of seedling length and biomass, was also adversely affected. A reduction in chlorophyll content of the cotyledonary leaves of C. occidentalis was also noticed, indicating an adverse effect on photosynthesis. Likewise, respiratory ability of growing seeds was also impaired in response to all four monoterpenes, clearly indicating that monoterpenes affect energy metabolism. On the basis of overall phytotoxicity, potency of monoterpenes was in the order of citronellal > linalool > citronellol > cineole. The results from this study suggest that both citronellal and linalool possess strong phytotoxic potential and can thus serve as lead molecules for the synthesis of bioherbicides.