Ethical practice     

Jim Berry 《The Canadian veterinary journal. La revue veterinaire canadienne》2014,55(1):1187-1190

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Ideotype design for lodging-resistant wheat   总被引：2，自引：0，他引：2  

P. M. Berry  R. Sylvester-Bradley  S. Berry 《Euphytica》2007,154(1-2):165-179

The plant characteristics required to make wheat lodging-proof for the least investment of biomass are calculated using a validated model of the lodging process and information about the dry matter costs of altering lodging-associated characters. The plant characteristics required to give a crop yielding 8 t ha⁻¹ with 500 shoots m⁻² and 200 plants m⁻², a lodging return period of 25 years include a height of 0.7 m, a root plate spread of 57 mm, and for the bottom internode a wall width of 0.65 mm with a diameter/material strength combination ranging from a diameter of 5.86 mm with a material strength of 20 MPa to a diameter of 4.00 mm with a material strength of 50 MPa. It is estimated that this ideotype would require 7.9 t ha⁻¹ of stem biomass and would have a harvest index of 0.42. Observations of a wide range of varieties grown using crop management to maximise lodging resistance without reducing yield potential showed that the root plate of the best variety was 7 mm less than the ideotype target, the stem character targets were achieved but not all in one variety, and the height target was achievable with the use of plant growth regulators. Plant breeders must therefore focus on selecting for a wider root plate and combining the appropriate stem strength characteristics.  相似文献   

Microbiology. How bacteria change gear     

Berry RM  Armitage JP 《Science (New York, N.Y.)》2008,320(5883):1599-1600

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Iridium abundances across the ordovician-silurian stratotype     

Wilde P  Berry WB  Quinby-Hunt MS  Orth CJ  Quintana LR  Gilmore JS 《Science (New York, N.Y.)》1986,233(4761):339-341

Chemostratigraphic analyses in the Ordovician-Silurian boundary stratotype section, bracketing a major extinction event in the graptolitic shale section at Dob's Linn, Scotland, show persistently high iridium concentrations of 0.050 to 0.250 parts per billion. There is no iridiumn concentration spike in the boundary interval or elsewhere in the 13 graptolite zones examined encompassing about 20 million years. Iridium correlated with chromium, both elements showing a gradual decrease with time into the middle part of the Lower Silurian. The chromium-iridium ratio averages about 10(6). Paleogeographic and geologic reconstructions coupled with the occurrence of ophiolites and other deep crustal rocks in the source area suggest that the high iridium and chromium concentrations observed in the shales result from terrestrial erosion of exposed upper mantle ultramafic rocks rather than from a cataclysmic extraterrestrial event.  相似文献