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991.
K. F. Thompson 《Euphytica》1964,13(2):173-177
A triple-cross method is described as an alternative to the double-cross method for the production in kale of 100 per cent hybrid seed. This new method would reduce the labour involved and improve yields in the early stages of seed multiplication. These advantages would justify slightly lower yields of forage from triple-cross hybrids than from double-crosses. 相似文献
992.
European Journal of Forest Research - 相似文献
993.
994.
995.
WRIGHT LD CRESSON EL SKEGGS HR PECK RL WOLF DE WOOD TR VALIANT J FOLKERS K 《Science (New York, N.Y.)》1951,114(2972):635-636
996.
997.
B Borsje A Heyting J R Roborgh D B Ross K W Shillam 《Journal of the Association of Official Analytical Chemists》1977,60(5):1003-1009
Two biological assays were conducted in which the antirachitic activity in chicks of 5,6-trans-vitamin D3 added to feed is compared with that of 5,6-cis-vitamin D3. On the basis of the results obtained it is concluded that the relative potency of the trans isomer is, at the most, 5% and that the antirachitic activity of the trans isomer is not markedly enhanced (an increase to a relative potency of 16%, at the most) if the cis isomer is also included in the diet. The results are not conclusive on the inhibition or lack of inhibition of the antirachitic activity of 5,6-cis-vitamin D3 by the presence of 5,6-trans-vitamin D3 in the feed. 相似文献
998.
999.
1000.
J.K. Martin 《Soil biology & biochemistry》1977,9(1):1-7
Wheat plants were grown in an atmosphere containing 14CO2 at temperatures of 10°C or 18°C for periods from 3–8 weeks. The plant roots were maintained under sterile or non-sterile conditions in soil contained in sealed pots which were flushed to displace respired 14CO2. The 14C content of the shoots, roots and soil was measured at harvest. The loss of 14C from the roots, expressed either in terms of total 14C recovered from the pots or 14C translocated to the roots, ranged from 14.3–22.6%, mean 17.3% or 29.2–44.4%, mean 39.2%, respectively. The presence of soil microorganisms significantly increased 14CO2 release from the rhizosphere but had no effect on the 14C content of the soil. Fractionation of 6 m HC1 hydrolysates from sterile and non-sterile soils showed the presence in all soils of material behaving as neutral sugars and amino acids, in quantities representing 5.9–9.2% and 13.4–17.2% of the soil 14C content for the sugar and amino acid fractions respectively. It is proposed that a major loss of root carbon resulted from autolysis of the root cortex. Root lysis was increased by soil microorganisms, apparently without penetration of the plant cell walls. 相似文献