Biological and molecular characterization of a novel carmovirus isolated from angelonia

ABSTRACT A new carmovirus was isolated from Angelonia plants (Angelonia angustifolia), with flower break and mild foliar symptoms, grown in the United States and Israel. The virus, for which the name Angelonia flower break virus (AnFBV) is proposed, has isometric particles, approximately 30 nm in diameter. The experimental host range was limited to Nicotiana species, Schizanthus pinnatus, Myosotis sylvatica, Phlox drummondii, and Digitalis purpurea. Virions were isolated from systemically infected N. benthamiana leaves, and directly from naturally infected Angelonia leaves, using typical carmovirus protocols. Koch's postulates were completed by mechanical inoculation of uninfected Angelonia seedlings with purified virions. Isometric particles were observed in leaf dips and virion preparations from both Angelonia and N. benthamiana, and in thin sections of Angelonia flower tissue by electron microscopy. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of dissociated purified virus preparations, a major protein component with a molecular mass of 38 kDa was observed. Virion preparations were used to produce virus-specific polyclonal antisera in both Israel and the United States. The antisera did not react with Pelargonium flower break virus (PFBV), Carnation mottle virus (CarMV), or Saguaro cactus virus (SgCV) by either enzyme-linked immunosorbent assay or immunoblotting. In reciprocal tests, antisera against PFBV, CarMV, and SgCV reacted only with the homologous viruses. The complete nucleotide sequence of a Florida isolate of AnFBV and the coat protein (CP) gene sequences of Israeli and Maryland isolates were determined. The genomic RNA is 3,964 nucleotides and contains four open reading frames arranged in a manner typical of carmoviruses. The AnFBV CP is most closely related to PFBV, whereas the AnFBV replicase is most closely related to PFBV, CarMV, and SgCV. Particle morphology, serological properties, genome organization, and phylogenetic analysis are all consistent with assignment of AnFBV to the genus Carmovirus.     

Effect of albumin and casein supplementation on the common carp Cyprinus carpio L. sperm motility parameters measured by CASA

Adhesion of sperm to a glass surface can be manifested by the low percentage of motile spermatozoa and lower speed. This crucial factor could disprove the sperm quality prediction from computer-assisted sperm analysis (CASA) results. In our study, this was particularly observed when solution L was used. However, protein supplementation was effective in the reduction in sperm adhesion. We found that albumin increased the sperm motility at concentrations of 0.25 % in solution L and 0.5 % in solution P. Casein was effective in both solutions at 0.25 % concentration. However, in solution L, the motility was lower than that measured in solutions P and L with the supplementation of BSA at 0.25 and 0.5 %. BSA supplementation was especially beneficial in terms of higher speed values regardless of an activation solution. Casein used with solution P allows us to obtain similar results as in the samples activated with BSA supplementation. Casein supplementation to solution L did not increase CASA results to the level observed in the samples activated with BSA added to the solution L. Our data suggest that the selection of an activation solution is one of the most crucial steps in the experiments requiring CASA data. Depending on the composition, different protein supplements should be used to reduce adhesion of sperm to a glass surface. We recommend the use of BSA at the 0.5–1 % concentration because at this level we obtained the highest CASA parameters in both activation media.     

Incidence of eyespot in winter wheat and quantification of the fungi Oculimacula acuformis and O. yallundae in Lithuania

Journal of Plant Diseases and Protection - Eyespot, caused by Oculimacula acuformis and O. yallundae, is one of the most damaging diseases in areas, including Lithuania, where mild and damp autumn...     

Source : sink ratio and leaf senescence in maize:: I. Dry matter accumulation and partitioning during grain filling

Whether the stay-green characteristic of recent maize hybrids is related to a larger source : sink ratio and/or a more efficient use of N during reproductive development was studied in a 3-year field experiment. The experiment was conducted with two short-season maize hybrids, Pride 5 (old) and Pioneer 3902 (recent), grown at two soil-N levels and with source : sink treatments during grain filling ranging from partial defoliation to no grain. Results confirmed that greater dry matter accumulation of Pioneer 3902, relative to Pride 5, was associated with greater leaf longevity. Change in stover weight from silking to maturity an indicator of the difference in supply and demand of assimilates during grain filling, varied from −30% with defoliation to +25% for the no sink treatment. The change was always greater in the new hybrid, indicating that the old hybrid was more source limited. Number of green leaves, an indicator of leaf longevity, was greatest when supply and demand of assimilates during grain filling were approximately equal. Leaf longevity was enhanced by an increase in soil N and the effect was larger in the high source : sink treatments, but differences in leaf longevity between the two hybrids were not influenced by soil-N level. In conclusion, increased leaf longevity of a new relative to an old hybrid was associated with a larger source : sink ratio during grain filling.     

Dynamics of the Biosynthesis of Niacin During Development to Maturity of Soybean Seed

Dynamics of the biosynthesis of niacin was followed in developing seed of four soybean genotypes under the defined climatic conditions in the course of three years. Tests were carried out at weekly intervals from the moment the seed was suitable for analysis up to its full maturity with the moisture content of about 14 %. Observation of the content of niacin determined more intensive synthesis of this vitamin in the third and fourth development stages, at the time of the highest cumulation of dry matter and metabolic activity. Maximal concentrations of niacin were noticed in the year in which along moderate temperatures considerably ampler precipitation was recorded. A comparison of the fluctuation of proteins and fatty acids with the fluctuation of niacin content confirm its role in the biosynthesis of these most important components of soybean seed.     

A possible relationship between viral infection and chromosome damage in breeding boars

A cytogenetic analysis of peripheral blood lymphocytes was carried out on breeding boars (n = 5) on a farm where viral infections (porcine parvovirosis) had occurred. Several different types of chromosomal aberrations were observed including chromatid breaks (23.60 +/- 2.88%), exchanges (9.60 +/- 8.99%), and fragments (4.26 +/- 3.31%). In addition, 2.94 +/- 1.74% of cells in metaphase showed pulverization. Cells with multiple aberrations were seen in two of five boars. The chromosomal damage in the boars may have been induced by a genotoxic agent such as a viral infection, and may also be related to the reproductive impairment of the pigs.     

ADSORPTION-DESORPTION CHARACTERISTICS OF HIGH LEVELS OF COPPER IN SOIL CLAY FRACTIONS

Copper adsorption and desorption under acid conditions by soil clay fractions separated from Vertisol, Planosol and Gleyic Acrisol has been studied in 0.01 M Ca(NO₃)₂. A Freundlich equation was appropriate to describe Cu adsorption. Within the range of 150 to 2600 mg of copper per kg of soil clay fraction the proportions of Cu not displaced during 5 successive 48-hour desorptions with 0.01 M Ca(NO₃)₂ decreased with increasing adsorption density and at the lower pHs. The proportions ranged from as high as 0.98 in th case of the Vertisol clay (pH 5.3) to as low as 0.12 (88% desorption) in the Planosol clay (pH 4.5). Measurement of separation factors (ga Cu/Ca) showed that the preference of the clay surface for Cu over Ca decreased in the order: Gleyic Acrisol > Planosol > Vertisol. A considerable amount of sorbed copper could be solubilized by decreasing pH values to 4 when in the Planosol clay 39% was desorbed and 45% was desorbed in the Gleyic Acrisol clay.     

Changing Phenology of Potato and of the Treatment for its Major Pest (Colorado Potato Beetle) – A Long-term Analysis

Potato Solanum tuberosum is one of the world’s four most important crops. Its cultivation is steadily increasing in response to the need to feed a growing world population. The yield of potato is influenced inter alia by both climate and pests. The main defoliator pest of potato is Colorado potato beetle Leptinotarsa decemlineata. Using data from a long-term experiment (1958–2013) in western Poland, we show that increasing temperature has affected the trophic relationship between potato and Colorado potato beetle. The planting, leafing, flowering and harvest dates for potato were advanced, after controlling for different cultivars, by 2.00 days, 3.04 days, 3.80 days and 3.42 days respectively for every 1 °C increase in temperature. In contrast, first treatment against Colorado potato beetle advanced by 4.66 days for every 1 °C increase in temperature, and, furthermore, the number of treatments against the beetle increased by 0.204 per 1 °C increase in temperature. This suggests that the beetle responds faster to increasing temperature than the plant does, but both parts of the system are probably greatly modified by farming practices.