Detection of minisatellite sequences inPhaseolus vulgaris

An improved procedure for detecting minisatellite sequences inPhaseolus vulgaris is described. Both M13 protein III tandem repeat and the 33.15 human mini-satellite sequences revealed polymorphisms with a high number of sharp bands after digestion of genomic DNA withHae III,Hinf I, orTaq I. Improved resolution of the numerous restriction fragments detected by these probes is accomplished by one or more of the following: varying agarose concentration, using high SDS hybridization buffer, exposure of the autoradiograph without intensifying screens, and transfer of the autoradiograph to electrophoresis paper. Increased stability of the DNA-DNA hybridizations with these heterologous probes is obtained by reducing hybridization temperature. Labeling probes with the polymerase chain reaction can accentuate some restriction fragments depending upon the radiolabeled nucleotide used.     

Detection and characterization of citrus tatter leaf virus (CTLV) and citrus yellow vein clearing virus (CYVCV) in citrus trees from Cyprus

Citrus tatter leaf virus (CTLV) was firstly reported of in California. After that, it reported in Australia, Korea, Nigeria, Japan, South Africa, and China. The transmission of this virus from plant to plant is very easy with mechanically. Citrus yellow vein clearing virus (CYVCV) was reported on lemon trees in India, Pakistan, Turkey and China. Foliar distortion, necrotic spots, chlorosis and wrinkling symptoms were observed in young lemon orchards in newly established orchards with trees imported from abroad. Therefore, surveys of citrus trees in Cyprus were performed for CTLV and CYVCV from 2013 to 2016. A total of 64 leaf samples from symptomatic citrus trees (41 lemon, 10 orange, 10 mandarin and three grapefruit samples) were collected for total nucleic acid extraction and RT-PCR with CTLV primers to amplify a 309 bp and a 614 bp fragment, respectively, of the 5′ end (100%) and high nucleotide sequence identity (99%) with isolates BJNM-2 and QC4 from China and isolate BDZ-1 from Australia. To our knowledge, this is the first report of CTLV from Europe.     

Forces involved in retention and movement of non-metabolic strontium inPhaseolus vulgaris

Summary Deposition of non-metabolic strontium was studied in tops of bean plants using Sr-89 as a tracer. Test solutions contained 2, 4 dinitrophenol as a metabolic inhibitor. Roots were severed from the plants to allow direct access of solutions into the plant top.The stem contained an efficient trapping mechanism for strontium, and removed the bulk of ion from the ascending stream soon after it entered the stem. Strontium buildup in the hypocotyl base adhered to the Freundlich gas equation. The process was to some degree reversible. These findings suggest that strontium binding involved electrostatic adsorption to charged sites along the route of upward movement. The significance of electrostatic retention on acropetal movement of strontium was discussed.Work performed under U.S. Atomic Energy Commission Contract AT(30-1)2117. Contribution number19 of the Storrs Agricultural Experiment Station, Storrs, Connecticut, U.S.A.     

Growth stimulation inPhaseolus vulgaris L. induced by gamma irradiation of seeds

Gamma radiation in doses 0.13 to 0.77 C kg^-1 (0.5 to 3.0 kR) significantly (P ≥ 0.01) stimulated seed germination, seedling height, and length of primary leaves of French bean cv. ‘Blue Lake’; these doses did not affect chlorophyll content per leaf area unit. Doses of 1.16 to 1.93 C kg^-1 (4.5 to 7.5 kR) induced inhibition of the four parameters studied.     

Effect of Growth Irradiance on Photosynthesis and Transpiration inPhaseolus vulgaris L.

In comparison with primary leaves of French bean plants grown under a photon flux density of 100 μeinstein m-2 s-1 (LP), leaves grown under 400 μeinstein m-2 s-1 (HP) were thicker (contained 82 to 104% more dry matter per blade area), had 44 to 48% higher stomatal frequency, 18 to 26% more chlorophyll (a + b) per leaf area unit and 31 to 42% less chlorophyll (a + b) per dry matter unit, 41% higher photosynthetic and 38% higher transpiration rates at light saturation, 33% higher stomatal conductance and 40% higher Photosystem 2 (H2O → K3[Fe(CN)6]) activity of isolated chloroplasts. There were no significant differences in the Photosystem 1 (TMPD/Ascorbate → MV) activity per unit amount of chlorophyll. Higher growth irradiance increased the ratio of frequencies of stomata in the upper/lower epidermes.     

Azimuthal sound localization in the European starling (Sturnus vulgaris)

Summary The physical measurements reported here test whether the European starling (Sturnus vulgaris) evaluates the azimuth direction of a sound source with a peripheral auditory system composed of two acoustically coupled pressure-difference receivers (1) or of two decoupled pressure receivers (2).A directional pattern of sound intensity in the freefield was measured at the entrance of the auditory meatus using a probe microphone, and at the tympanum using laser vibrometry. The maximum differences in the soundpressure level measured with the microphone between various speaker positions and the frontal speaker position were 2.4 dB at 1 and 2 kHz, 7.3 dB at 4 kHz, 9.2 dB at 6 kHz, and 10.9 dB at 8 kHz. The directional amplitude pattern measured by laser vibrometry did not differ from that measured with the microphone. Neither did the directional pattern of travel times to the ear. Measurements of the amplitude and phase transfer function of the starling's interaural pathway using a closed sound system were in accord with the results of the free-field measurements.In conclusion, although some sound transmission via the interaural canal occurred, the present experiments support the hypothesis 2 above that the starling's peripheral auditory system is best described as consisting of two functionally decoupled pressure receivers.Abbreviations CM cochlear microphonics - ITD interaural time difference - IID interaural intensity difference - MRA minimum resolvable angle - dB SPL sound-pressure level (re 0.00002 Pa)     

Post-illumination burst of carbon dioxide inPhaseolus vulgaris L. as affected by leaf temperature

The effect of leaf temperature on the post-illumination burst of CO₂ (PIB) in 15 day-old primary bean leaves (Phaseolus vulgaris L.) was studied by means of infrared gas analysis in a closed gas exchange system. The amplitude and kinetic of PIB was different with its own characteristic course for different temperature steps. The temperature optimum for the PIB at 21% O₂ near the carbon dioxide compensation concentration Λ (150 mg m^-3) was 33 °C while that for net photosynthetic rate (P _N) at 21% O₂ and 600 mg m^-3 CO₂ was 24.5 °C. The PIB was observed to 12…33 s after the darkening of leaves. No PIB was observed at 2% O₂. The applicability of PIB as an estimate of photorespiration rateR _p has been proved by comparing it with extrapolation of the relationship betweenP _n and CO₂ concentration to zero.     

Citrus tristeza virus replicates and forms infectious virions in protoplasts of resistant citrus relatives

Citrus tristeza virus (CTV) is the most economically important viral disease of citrus worldwide. Cultivars with improved CTV tolerance or resistance are needed to manage CTV-induced diseases. The citrus relatives Poncirus trifoliata (L.) Raf., Swinglea glutinosa (Blanco) Merr., and Severinia buxifolia (Poir) Ten. are potential sources of CTV resistance, but their resistance mechanisms are poorly characterized. As a first step to examine the mechanisms of resistance to CTV in these citrus relatives and selected Citrus × Poncirus hybrids, it was necessary to develop methods for protoplast isolation and viral inoculation to allow examination of CTV multiplication in this range of citrus varieties and relatives. Leaf and/or cultured cell protoplasts were isolated and inoculated with four biologically distinct CTV isolates. Northern-blot hybridization analyses for progeny RNAs and immuno-electron microscopy assays for newly produced virions showed that CTV replicated and produced infectious particles in protoplasts from all of the resistant plants tested. These results suggest that resistance to CTV observed at the plant level results from a lack of virus movement and/or some induced resistance response, rather than lack of viral multiplication at the cellular level.     

Fruit dimorphism inPhaseolus sublobatus (Fabaceae) and its evolutionary significance

Populations of the annualPhaseolus sublobatus from different ecogeographical zones are genetically differentiated. In twelve populations from the western ghats (Maharashtra range) chasmogamous flowers are arranged in peduncled capitate racemes borne in leaf axils of higher nodes. One population (Poona Race S₄) has additional inflorescences, also with chasmogamous flowers, on the main axis between the cotyledonary node and the ground. When the pods of these flowers ripen, the inflorescence gradually coils and, eventually, gets bury the fruits in the soil. This phenomenon is not known in any other plant.—The seed-coat patterns as revealed by SEM, and germination behaviour of both aerial and subterranean seeds are similar, and both types of seeds lack dormancy.—Heavy seed predation selection pressure is probably the principal cause for the evolution of fruit dimorphism inP. sublobatus. The origin of geocarpy in relation to fruit dimorphism and seed predation is discussed.     

Effects of l-alkyl-l-ethylpiperidinium bromide detergents on Mg2+-ATPase activity inPhaseolus vulgaris andZea mays

l-alkyl-l-ethylpiperidinium bromides inhibited light induced Mg²⁺-adenosin-triphosphatase activity of isolated thylakoids in both Phaseolus vulgaris L. and Zea mays L. The short chain detergents (C₅ to C₇) were less effective in maize than in bean.     

Study of the viral interference between infectious pancreatic necrosis virus (IPNV) and infectious haematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss)

The resistance of rainbow trout (Oncorhynchus mykiss) to an infectious haematopoietic necrosis virus (IHNV) challenge following a preceding non-lethal infection with infectious pancreatic necrosis virus (IPNV) was investigated through experimental dual infections. Trout initially infected with IPNV were inoculated 14 days later with IHNV. Single infections of trout with 1 of the 2 viruses or with cell culture supernatant were also carried out and constituted control groups. No mortality was noted in fish after a single infection with IPNV. This virus had no influence on the head kidney leucocyte phagocytic activity and plasma haemolytic complement activity. IHNV induced a high mortality (72%) and reduced the macrophage phagocytic activity and complement haemolytic activity. It also induced a late production of anti-IHNV antibodies which occurred after clearance of the virus in the fish. In trout co-infected with both viruses, a mortality rate of 2% occurred and the immune parameters were similar to those observed in the fish infected with IPNV only, demonstrating that in co-infected trout IPNV inhibits the effects of IHNV. The studied parameters did not allow us to define the mechanism of interference occurring between these 2 viruses, but some hypothesis are put forward to explain the interference between the 2 viruses.     

Citrus tristeza virus (CTV) resistance in transgenic citrus based on virus challenge of protoplasts

Summary A strategy for the sereening of candidate virus-derived sequences to provide RNA-mediated citrus tristeza virus (CTV) resistance and early selection of virus-resistant citrus is presented. The system is based on the polyethylene glycol-(PEG) mediated cotransformation of protoplasts using virus-derived sequences and green fluorescent protein as a single selectable marker, followed by an in vitro assay of virus inoculation into transgenic protoplasts to determine the level of citrus tristeza virus replication. A cotransformation rate higher than 20% allowed selection of several clones carrying the desired transgenes. Efficient in vitro inoculation of virus in transgenic protoplasts was performed. Tobacco mosaic virus virions were used as a control in order to check eitrus protoplast viability. Different CTV replication levels were detected in transgenic clones. Only one clone showed no replication of CTV. Considerations regarding selection of candidate virusderived sequences and virus challenge of transgenic cells are presented.     

Restriction fragment length polymorphisms of the phytohemagglutinin genes inPhaseolus andVigna (Leguminosae)

Restriction fragment length polymorphisms at the phytohemagglutinin (PHA) locus were determined among 21 genotypes ofPhaseolus vulgaris, P. coccineus, P. acutifolius, P. lunatus, and threeVigna species, using five restriction enzymes and one double digestion, in order to provide molecular evidence for their genetic relatedness. The dissimilarity between genotypes was estimated from binary RFLP data. The dissimilarity was high among species (from 0.75 to 0.95), and of variable extent among genotypes of the same species (0.33–0.89). InP. vulgaris, two different DNA hybridization patterns were found, giving further evidence for two major gene pools in that species. The restriction patterns ofP. vulgaris var.aborigineus, the putative ancestral form ofP. vulgaris, exhibit clear homology toP. vulgaris genotypes. An undefined landrace from Taiwan could be identified as aP. vulgaris genotype. RFLP-based trees for the phytohemagglutinin genes of the species studied were computed with several distance matrix and parsimony methods.