bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on plant growth‐regulating substances
Authors: WILCOX E. J. , WAIN R. L. 
Published: February 2008

SUMMARYA report of an alkoxypurine showing cytokinin activity is presented. This compound, 6‐benzyloxypurine, has been tested in three tests and in two of these, a wheat leaf senescence and a young coleoptile test, the compound is as active as benzyladenine or kinetin. Although it is much less effective on molar basis than these compounds in a tobacco tissue culture test, it is as active at its optimum concentration. In addition to promoting cell division the presence of 6‐benzyloxypurine leads to morphological differentiation within the tobacco stem tissue, and whole plants have been grown without altering the nutrient medium.
Heat inactivation of cucumber mosaic virus in cultured tissues of Stellaria media
Authors: WALKEY D. G. A. , COOPER JANICE 
Published: February 2008

SUMMARY In vivo heat inactivation of cucumber mosaic virus (CMV) was studied in a low‐temperature‐tolerant species, Stellaria media. Infectivity remained high in infected 5. media cultures grown at 25 °C or less, but could not be detected in cultures incubated at 32 °C for 28 days. When infected tissues were grown at 12–32 °C for 24 days, virus was still detectable at a low level in cultures incubated at 30 °C. The highest level of infectivity was in cultures at 12 °C.
Investigations of carnation viruses
Authors: HOLLINGS M. , STONE OLWEN M. , ATKEY P. T. , BARTON R. J. 
Published: February 2008

SUMMARYCarnation vein mottle virus (CarVMV) is rare in glasshouse carnations in Britain, although locally common in Dianthus barbatus in private gardens. In Sim carnations free from other viruses, CarVMV caused slight diffuse chlorotic mottling in the younger leaves, decreased flower yield by c. 22%, and caused flower breaking in cvs William Sim and Dusty. In non‐Sim cultivars Pink Shibiuya, Orchid Beauty and Vesta, leaf symptoms and flower breaking were more pronounced. In mixed infections with carnation mottle virus, symptoms were much more severe.CarVMV was not eliminated from carnation or D. barbatus plants grown for 4 wk at 37oC, and only rarely from cuttings then taken from them, but it was readily eliminated by meristem‐tip culture. Myzus persicae adults or nymphs acquired and transmitted the virus within a total time of 4 min, and remained infective for 30–60 min if feeding, or for 75 min if starved. The carnation aphid, M. persicae f. dianthi, transmitted the virus much less efficiently. The virus was not transmitted by dodder (Cuscuta campestris), or through seed of D. barbatus or Chenopodium quinoa. The maximum infective dilution in sap of D. barbatus, carnation and C. quinoa ranged from 10‐2 to 10‐5. The virus withstood 10 min at 60 but not 65oC, up to 9 days at c. 18oC or 3–4 wk at c. 2oC.CarVMV infected twenty‐two of 107 plant species in six of thirty‐seven families; suscepts were confined to the Chenopodiaceae, Caryophyllaceae and closely allied families. C. quinoa was the best local lesion assay host. Seedling clones of D. barbatus, selected as resistant to carnation mottle virus, proved the best indicator and propagation species.Up to 50 mg virus/kg tissue were obtained by butanol clarification followed by differential and density gradient centrifugation. The preparations contained a single sedimenting component, s20w= 144S, and had flexuous filamentous particles, c. 790 times 12 run; the particles contained a single polypeptide, mol. wt 34800, and 5% of a single‐stranded ribonucleic acid (RNA) with nucleotide base ratios of G21: A25: C25: U29.Serologically CarVMV was related distantly to turnip mosaic (cabbage black ring strain), pea mosaic, watermelon mosaic (Strain 2) and bean yellow mosaic viruses, more closely to pepper veinal mottle virus, but unrelated to twelve other potyviruses.CarVMV is not at present a danger to carnation crops in Britain, but the recent trend of sending carnation plants to overwinter outdoors in warmer countries involves potential risks of more rapid spread by effective vector races of M. persicae.
The elimination of ryegrass mosaic virus from Lolium multiflorum by meristem tip culture
Authors: DALE PHILIP J. 
Published: February 2008

SUMMARYMeristem tips were cultured from Lolium multiflorum plants infected with ryegrass mosaic virus (RMV). Meristem tips within the size range O'2‐fi mm long were cultured on media with or without2,4‐D at 1 mg/1. The plants that regenerated in culture showed no symptoms over a 10 month period and no RMV particles were observed by electron microscopy. It was concluded that RMV had been eliminated. The method should prove useful in eliminating the virus from desirable genotypes used as parent material for seed production.
Genetic adaptation for vernalization requirement in Nepalese wheat and barley
Authors: RAO A. R. , WITCOMBE J. R. 
Published: February 2008

SUMMARYA large number of accessions of covered and naked barley from eastern Nepal were grown without vernalization, and it was found that naked barley accessions were predominantly spring varieties while covered barley accessions were predominantly winter varieties. Seven accessions were subjected to a range of vernalization periods. Four naked varieties were spring varieties, although one showed some response to vernalization, but the three covered barleys were winter varieties.Although the majority of naked barleys are spring forms, they are winter sown at high altitudes and this does not conform to the distribution of naked barley described by Takahashi (1955).Wheat accessions which came from villages situated at high altitudes tended to have higher vernalization requirements than those which came from lower altitudes. This was taken to indicate local adaptation and a low movement of seeds (gene‐flow) between villages. The relationship between vernalization requirement and altitude was not found in barley.Marked but contrasting regional patterns for vernalization requirement occurred in the wheat and covered barley. It was concluded that gene‐flow was greater within regions than between them. This regional isolation together with environmental heterogeneity are major diversity promoting mechanisms.
A laboratory method of screening fungicides for systemic activity against Bretnia lactucae
Authors: CRUTE I. R. , WOLFMAN S. A. , DAVIS A. A. 
Published: February 2008

SUMMARYA soil‐free in vivo laboratory technique is described for the detection of systemic anti‐fungal activity against Bretnia lactucae, a representative of the Peronosporales. This system is not subject to some of the complications encountered with in vitro and glasshouse experiments. Two new compounds (prothiocarb and LS 73–1038 (Nina)) were found to have high systemic activity against B. lactucae using this technique and it was confirmed that zineb also has some systemic effect. Streptomycin sulphate and DPX‐3217 showed some activity but were phytotoxic. Dowco 269 was phytotoxic and showed no activity against B. lactucae. None of these chemicals showed any significant vapour activity.
Carbohydrate metabolism and respiration after harvest of the cultivated mushroom, Agaricus bisporus
Authors: Hammond J. B. W. , Nichols R. 
Published: February 2008

ABSTRACTThe carbohydrate metabolism of the mushroom and the respiration of the sporophore after harvest at different stages of growth have been studied. Mannitol and trehalose were found to be the major soluble carbohydrates in the sporophore and mycelium respectively. Mannitol and trehalose levels fall during sporophore storage, and feeding experiments with14C‐labelled sugars indicate that they are metabolised. The results were discussed in relation to the post‐harvest development of the sporophore.
Factors affecting the resistance of cold‐stored carrots to Botrytis cinerea
Authors: GOODLIFFE J. P. , HEALE J. B. 
Published: February 2008

SUMMARYThe secondary phloem parenchyma of cold‐stored turgid roots of carrot (Daucus carota) is capable of localizing mycelial infection by Botrytis cinerea, producing a dark resistant lesion. The percentage of roots exhibiting this reaction declined with increasing time in cold‐store: when freshly harvested and wound‐inoculated in October 1974, 99%of roots resisted invasion, whereas only 5% of those stored until March 1975 did so. The surface dimensions of resistant lesions did not increase between 33 and 55 days after inoculation. However, the surface dimensions and mean weights of lesions (arising from inoculations performed at different times over the course of the storage season) were both larger with increasing time in storage of roots prior to inoculation. The ability of the root tissue to localize infection was reduced if the roots lost 5–10% or more of their fresh weight before inoculation, resulting progressively in susceptibility. Compared with roots wound‐inoculated using mycelial disks, there was an overall reduction in infection when carrots were wound‐inoculated using conidia or when conidia or mycelial disks were inoculated onto the apparently undamaged surface of roots.
Aspects of the biological activity of surfactants that are potential eradicants of apple mildew
Authors: HISLOP E. C. , BARNABY VIVIEN M. , BURCHILL R. T. 
Published: February 2008

SUMMARYAmong several surface active agents tested, both anionic and cationic materials usually caused greater changes in the microflora of treated soil than non‐ionic materials, although the effects of a non‐ionic formulated mixture of aliphatic alcohols (Off‐Shoot T) were considerable. In vitro tests with micro‐organisms and earthworms indicated similar differences in response to types of compound. There was a positive correlation between hydrophobicity and biological activity of a series of alkyl phenol ethoxylates in some tests. Although many surfactants caused gross phytotoxicity to cress (Lepidium) seedlings in the laboratory, the growth of barley and pea seedlings in treated soil was significantly decreased only by one cationic material.
The detection of three viruses of hop (Humulus lupulus) by enzyme‐linked immunosorbent assay (ELISA)
Authors: THRESH J. M. , ADAMS A. N. , BARBARA D. J. , CLARK M. F. 
Published: February 2008

SUMMARYThe recently described technique of enzyme‐linked immunosorbent assay (ELISA) was used throughout the 1976 growing season to detect hop mosaic, arabis mosaic and prunus necrotic ringspot viruses in hop plants. On each occasion virus was detected quickly, conveniently and with great sensitivity. The technique was particularly suitable for processing numerous samples collected from the field.Serious difficulties and limitations were encountered in testing comparable material by established techniques. The serology test for the hop strain of arabis mosaic virus by double diffusion in agar gels was very insensitive and only worked satisfactorily early in the growing season. Grafting sensitive Golding hop varieties to detect hop mosaic virus was inconvenient and time‐consuming and symptom expression was so slow and erratic that glasshouse space was utilized for long periods. It became impossible to detect prunus necrotic ringspot virus by sap inoculations to cucumber during an exceptionally hot period in mid‐summer.The possibilities are discussed of exploiting the ELISA technique for use in large scale surveys and epidemiological studies on viruses of hop and other crops. Changes in the current methods of handling and extracting leaves are considered for increasing the throughput of samples.
Antifungal compounds in winter wheat resistant and susceptible to Septoria nodorum
Authors: BAKER ELIZABETH A. , SMITH I. M. 
Published: February 2008

SUMMARYThe content of benzoxazinone compounds in Septoria nodorum resistant and susceptible wheat cultivars fell with time, reaching an undetectable level 3–4 wk after germination. The compounds were absent from field‐grown plants extracted at growth stages 2–3, 6–7, 10, 10.5 and 11. Additional antifungal compounds were detected in healthy and diseased field‐grown plants of both cultivars at all growth stages, although qualitative and quantitative differences in inhibitory activity were small and their role in resistance remains open to discussion.
The flow of water into fruit trees. I. Resistances to water flow through roots and stems
Authors: BAXTER P. , WEST D. 
Published: February 2008

SUMMARYRelative conductivity (K) to water in healthy apple trees ranged from maximum values of 18.2 cm3.100 s‐1.cm length.0.001 Pas.kPa‐1.cm‐2 xylem area, for major suberized roots to values of 1.6 for 1‐yr‐old twigs. The values for equivalent parts of healthy cherry trees were 26.3 and 3.3. Trees with roots affected by the larvae of the fruit tree root weevil (Leptopius squalidus) which causes either chronic growth decline or sudden wilting and death, had values as low as 1% of healthy trees, in those parts of the tree showing wilting and lack of growth.Water flow under pressure into the root systems of healthy apple trees increased linearly with increases in pressure from 200 to 800 kPa. Flows into dormant and active root systems respectively were 0.6 and 1.7 cm3.100 s‐1. 100 cm2 root surface area. 100 kPa‐1.
The involvement of fungi in the breakdown of sulphited strawberries
Authors: Dennis C. 
Published: February 2008

ABSTRACTBetween 8000 and 9000 tons of strawberries are used annually for jam manufacture in the UK, c. 65 % of which are stored in sulphite liquor (6 % SO2+lime, c. pH 3.0). Sporadic cases of disintegration of sulphited strawberries have been observed increasingly in recent years.In laboratory experiments breakdown of whole berries in sulphite liquor was achieved by including berries partly rotted with Mucor mucedo, Rhizopus sexualis or R. stolonifer, 1.5‐2.5 % infected material causing complete breakdown of all of the berries. The inclusion of up to 25 % berries infected with Botrytis cinerea caused no softening of the berries. The addition of culture filtrates to whole fruit in sulphite liquor confirmed observations with the above fungi but also showed that pectolytic enzymes from Aureobasidium pullulans and Trichosporon pullulans could cause breakdown.The incidence of spoilage fungi on commercially harvested fruit indicated that M. mucedo and R. sexualis were the main cause of breakdown, but that A. pullulans increased tenfold on fruit stored at 15 °C overnight before sulphiting. Results from commercially harvested fruit (cv. Cambridge Favourite) in 1975 and 1976 showed that: (I) fruit should be sulphited as soon as possible after harvest, since the storage of harvested fruit prior to sulphiting may give a poorer quality product; (2) there is little difference in breakdown of fruit from plants treated with the pre‐harvest fungicides, Elvaron, Mildothane, or Daconil, and (3) fruit grown in different areas of the UK shows varying amounts of breakdown. This may be due to differences in the infection level of Phycomycetes and contamination by other pectolytic fungi or inherent differences in the susceptibility of the fruit to enzyme attack.
Effects of cultural practices, Verticillium nubilum and locality on coiled sprout and yield of early potatoes
Authors: LAPWOOD D. H. , HIDE G. A. , LENNARD J. H. 
Published: February 2008

SUMMARYTreatments reported to affect the incidence of ‘coiled sprout’ were studied in 1968 with the cultivar Arran Pilot in experiments near Falmouth, Cornwall (F), Rothamsted (R) and near Edinburgh (E).Most coiled stems occurred at E (37%) with similar proportions at R (19%) and F (16%). Seed tubers with the longest sprouts at planting produced most coils at all sites, those with shorter sprouts less and unsprouted seed least. When coiling was assessed on the number of plants, long‐ and short‐sprouted seed tubers were about equally affected at R and E.Sprouts emerged within 45 days at E and 30 days at R. Longer sprouts did not emerge more quickly, but emergence was more than 1 wk later from unsprouted seed at R and only a few days later at E. Harrowing ridges after planting to decrease the depth of soil covering seed tubers hastened emergence by about 1 wk at R and decreased the incidence of coiling; it had little effect at E but tended to increase coiling at F.Seed tubers inoculated with Verticillium nubilum produced more coiled sprouts but this increase was not significant.The highest final yields were achieved at R (43‐2 t/ha) where short‐sprouted seed outyielded long‐sprouted and unsprouted seed, but cultivation treatments and fungus inoculation had no effect. At E (21‐2 t/ha) only herbicide treated plots gave a significant effect, outyielding harrowed plots by 8 t/ha. At F (18‐2 t/ha) short‐sprouted seed outyielded long‐sprouted and unsprouted seed, and herbicide treated plots outyielded harrowed plots.When ware yields from individual plants with and without coils from long‐sprouted seed were compared at R on 18 June, coiled plants gave about 30% and on 2 July 60% of the yield of non‐coiled, but by 16 July 120% yield (20% more); similar trends were shown by short‐ and by long‐sprouted seed at E.
Effectiveness of late copper and streptomycin sprays for the control of halo‐blight of beans (Pseudomonas phaseolicola)
Authors: TAYLOR J. D. , DUDLEY C. L. 
Published: February 2008

SUMMARYTwo sprays of copper oxychloride or streptomycin sulphate (0–1 % a.i., 675 1/ha) applied to dwarf beans at first flowering and at pod set reduced pod infection by c. 70%. When applied as single sprays at pod set, copper was more effective than streptomycin and reduced pod infection by 50%. Although a copper spray at pod set increased the proportion of pods suitable for processing, more effective control was obtained with a regular spray programme, commencing at the seedling stage.
Pathology, soil transmission and characterization of cymbidium ringspot, a virus from cymbidium orchids and white clover (Trifolium repens)
Authors: HOLLINGS M. , STONE OLWEN M. , BARTON R. J. 
Published: February 2008

SUMMARYTwo strains of a virus, designated cymbidium ringspot virus (CyRSV), were isolated from cymbidium orchids and from Trifolium repens respectively in Britain. Experimentally infected cymbidiums developed slight chlorotic ring‐mottle; T. repens developed flecks and mottling in the leaves, and slight stunting. Of 101 plant species tested, the cymbidium strain infected sixty‐one (thirteen systemically) in twenty‐three of thirty‐five families; the clover strain infected sixty‐four species (eighteen systemically) in twenty‐two families. Both strains were propagated in Nicotiana clevelandii and assayed in Chenopodium quinoa.CyRSV was readily transmitted by inoculation of sap, and by foliage contact between plants, but not by the aphids Myzus persicae or Acyrtho‐siphon pisum, nor through seed of T. incarnatum, Phaseolus vulgaris or N. clevelandii. Highly infective virus was released into soil from roots of infected N. clevelandii, and acquired by bait seedlings planted in such soil. Similar transmission occurred when purified virus was applied to the surface of sterilized soil containing bait plants; there was no evidence for any living soil vector.The virus was eliminated from 96 % of small cuttings taken from infected N. clevelandii plants grown at 35–37 °C for 9 wk.CyRSV was still infective in sap of N. clevelandii after dilution to 10˜5‐io–6 (only 2 × 10_1 in cymbidium sap), or after 10min at 85–90 °C. It survived at least 10 months at c. 20 °C and more than 12 yr at 2 °C. Lyophilized sap was highly infective after over 13 yr at laboratory temperatures under high vacuum.Purified preparations made by clarification with n‐butanol, followed by differential centrifugation and exclusion chromatography on controlled‐pore glass beads, contained isometric particles c. 30 nm diam., with s°20W= 137 S, and had a buoyant density in caesium chloride of 1–36 g/ml. The A 260/A 280 ratio was 1–55, and A max(26o)/A min(242) was 1–17. The virus contained c. 15 % of single‐stranded RNA of mol. wt 1–7 × 106; the nucleotide base ratios were: G27'8; A24/9; C2I‐3; U26‐I. There was one capsid polypeptide of mol. wt 43600.The virus was a good immunogen and a strongly reacting antigen in vitro; in Immunoelectrophoresis, each strain migrated as a single antigenic component towards the cathode. The cymbidium and clover strains were serologically closely related, although spurs were produced in immunodiffusion. No serological relationship was found to forty‐three other isometric viruses, including eighteen tombusvirus isolates; CyRSV nevertheless shares many properties with tombusviruses, and we assign it provisionally to this group. The cryptogram is: R/r:1:7/15:S/S:S/O.
Studies on plant growth‐regulating substances
Authors: FARRAHI‐ASCHTIANI S. , TAYLOR H. F. , WAIN R. L. 
Published: February 2008

SUMMARYThe dwarfing of seedlings of Phaseolus vulgaris cv. Masterpiece by treatment with solutions of 4‐chlorobenzyltributylammonium bromide (B4) as a foliar spray or by application to the roots has been demonstrated. Dwarfing resulted from a reduction of internodal and petiolar lengths but there was no evidence of delayed leaf or flower development. A reduction in transpiration rate was accompanied by some protection against wilting and an increased ability to recover from this condition. No changes in transpiration coefficient were observed.The primary leaves of treated seedlings retained chlorophyll longer than those of control seedlings, but in other leaves, chlorophyll and carotenoid pigment levels tended to fall following treatment with B4. Evidence was obtained that B4 treatment delayed root nodule formation, an effect which could be associated with the antibacterial properties of quaternary ammonium salts.
A technique for the location of planthopper feeding probes using labial imprints
Authors: WATERS HENRY 
Published: February 2008

SUMMARYLabial imprints mark precisely a planthopper's feeding probe. By staining a leaf surface with 1 % aniline blue in lactophenol, the labial imprints may be detected. This technique provides a simple method for the location of stylet tracks without having to kill feeding insects in situ. Using the leaf surface staining technique, the labial imprints of Haplaxius crudus van Duzee (Homoptera; Cixiidae), a possible vector of lethal yellowing of coconuts, were shown to be 70–80μm in diameter with a raised central crown. Such imprints are the mirror image of the distal labial surface.
The identification of mild and severe strains of tobacco mosaic virus in doubly inoculated tomato plants
Authors: CASSELLS A. C. , HERRICK C. C. 
Published: February 2008

SUMMARYUsing specific antisera, it was possible to identify mild (MII‐16) and the 0 and 1 strains of tobacco mosaic virus (TMV) in tomato plants infected with the mild strain following challenge inoculation with the wild strains.In addition, with single lesion isolates of the MII‐16 and o strains it has been shown that both strains can be assayed simultaneously in mixed isolates on Nicotiana glutinosa based on differences in local lesion size. The accuracy of this differential local lesion assay was c. 90% as determined by back inoculation of single lesion isolates into susceptible tomato cultivars.
Experiments with fungicide sprays in late summer and early autumn on sugar‐beet root crops
Authors: BYFORD W. J. 
Published: February 2008

SUMMARYFentinhydroxide and benomyl sprayed on to sugar‐beet root crops in July, August and September frequently increased yield of tops. Sugar yield was increased only if either powdery mildew or virus yellows was prevalent, when on average a single fentinhydroxide spray at 0·7 kg a.i./ha increased sugar yield by 8% and yield of tops by 13%. The mildew specific fungicide fluotrimazole also increased yield, but it could not be determined whether this was due to controlling powdery mildew or secondary parasitic fungi attacking yellows‐infected plants. Repeated sprays of both fentinhydroxide and fluotrimazole, but not benomyl, appeared to be phytotoxic when applied in hot dry weather.