Barley Stripe Mosaic Virus (<Emphasis Type="Italic">Virgaviridae,Hordeivirus</Emphasis>) As Etiological Agent of Maize Chlorotic Stripe Disease

The presence of barley stripe mosaic virus (BSMV) (Virgaviridae, Hordeivirus) infection background in maize (Zea mays) crops in the territory of Primorsky krai was demonstrated. Field data and model experiments established that BSMV causes the disease formerly called “maize chlorotic stripe disease” with the following symptoms: general chlorosis of leaves at the early stages of plant development, the emergence of pale yellow, nearly white strikes along the midrib throughout the length of the leaf, and loss of infected plants to the stage of pulling (12–25%; average value of 17.1%) and elongation with the absence of severe death in the later stages. The coefficient of harmfulness for BSMV (37.1%) was determined in the study. We concluded that planned monitoring in relation to BSMV is required for planting maize.     

Cosmogenic and primordial radionuclides in lunar samples by nondestructive gamma-ray spectrometry

The (7)Be, (22)Na, (26)Al, (44)Ti, (46)SC, (48)V (51)Cr, (54)Mn, (56)Co, (57)Co, (57)CO, (40)K, (238)U, and (232)Th were measured in lunar fines and portions of three rocks. Major production of cosmogenic radionuclides is due to solar protons, thus their concentrations are far different than those in meteorites. Surface exposures of the rocks and fines are long compared with the 0.74 million year half-life of (26)Al. Lunar fines show substantially higher concentrations of low energy reaction products. The ratios of thorium to uranium are extremely constant at 3.8, which indicates very little geochemical differentiation and are in good agreement with a common nucleosynthesis for lunar and earth materials.     

Verification, validation, and confirmation of numerical models in the Earth sciences

Verification and validation of numerical models of natural systems is impossible. This is because natural systems are never closed and because model results are always nonunique. Models can be confirmed by the demonstration of agreement between observation and prediction, but confirmation is inherently partial. Complete confirmation is logically precluded by the fallacy of affirming the consequent and by incomplete access to natural phenomena. Models can only be evaluated in relative terms, and their predictive value is always open to question. The primary value of models is heuristic.     

Magnetic flux transport on the sun

Although most of the magnetic flux observed on the sun originates in the low-latitude sunspot belts, this flux is gradually dispersed over a much wider range of latitudes by supergranular convective motions and meridional circulation. Numerical simulations show how these transport processes interact over the 11-year sunspot cycle to produce a strong "topknot" polar field, whose existence near sunspot minimum is suggested by the observed strength of the interplanetary magnetic field and by the observed areal extent of polar coronal holes. The required rates of diffusion and flow are consistent with the decay rates of active regions and with the rotational properties of the large-scale solar magnetic field.     

Use of LOD score technology in mapping quantitative trait loci in plants

The use of LOD score analysis developed on the basis of the maximum likelihood method for establishing genetic linkage between loci determining the manifestation of quantitative traits and molecular markers in plant genetics is examined. Experimental data on the use of this approach for revealing LOD values in higher plants for the example of mapping Brassica rapa L. populations are given.     

Use of interspecific hybridization for increasing buckwheat tolerance to inbreeding

The productivity of inbred buckwheat lines I₁–I₈ with the homostyly gene of Fagopyrum esculentum and Fagopyrum homotropicum is studied. The species F. homotropicum is recommended for use in buckwheat breeding as a donor of homostyly and tolerance to inbreeding depression.