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The BaYMV resistance of German cultivars like Diana, Franka, Gloria or Sonate is due to one recessive gene (‘German gene’), located on barley chromosome 3. This gene and the gene Ym1 are most probably allelic (or tightly linked). Resistance of the American cv. Anson barley is inherited independently of the ‘German gene’ and Ym1. The haploidy technique is an efficient means for approaching major breeding goals: (1) to improve quality characteristics of cultivars carrying‘German resistance' (2) to adapt exotic germplasm carrying the gene Yml to European growing conditions; (3) to broaden the genetic base of BaYMV resistance by incorporating additional ‘new’ resistance genes. 相似文献
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The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor 总被引：1，自引：0，他引：1
GM Keating SW Bougher RW Zurek RH Tolson GJ Cancro SN Noll JS Parker TJ Schellenberg RW Shane BL Wilkerson JR Murphy JL Hollingsworth RM Haberle M Joshi JC Pearl BJ Conrath MD Smith RT Clancy RC Blanchard RG Wilmoth DF Rault TZ Martin DT Lyons PB Esposito MD Johnston al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676
The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere. 相似文献
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S. A. HASSAN F. BIGLER P. BLAISINGER H. BOGENSCHÜTZ J. BRUN P. CHIVERTON E. DICKLER M. A. EASTERBROOK P. J. EDWARDS W. D. ENGLERT S. I. FIRTH P. HUANG C. INGLESFIELD F. KLINGAUF C. KÜHNER M. S. LEDIEU E. NATON P. A. OOMEN W. P. J. OVERMEER P. PLEVOETS J. N. REBOULET W. RIECKMANN L. SAMSOSE-PETERSEN S. W. SHIRES A. STÄUBLI J. STEVENSON J. J. TUSET G. VANWETSWINKEL A. Q. VAN ZON 《EPPO Bulletin》1985,15(2):214-255
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Mid-ocean ridge basalts (MORBs) and ocean island basalts (QIBs) are derived by partial melting of the upper mantle and are marked by systematic excesses of thorium-230 activity relative to the activity of its parent, uranium-238. Experimental measurements of the distribution of thorium and uranium between the melt and solid residue show that, of the major phases in the upper mantle, only garnet will retain uranium over thorium. This sense of fractionation, which is opposite to that caused by clinopyroxene-melt partitioning, is consistent with the thorium-230 excesses observed in young oceanic basalts. Thus, both MORBs and QIBs must begin partial melting in the garnet stability field or below about 70 kilometers. A calculation shows that the thorium-230-uranium-238 disequilibrium in MORBs can be attributed to dynamic partial melting beginning at 80 kilometers with a melt porosity of 0.2 percent or more. This result requires that melting beneath ridges occurs in a wide region and that the magma rises to the surface at a velocity of at least 0.9 meter per year. 相似文献
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