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SUMMARY: In dilute nutrient solutions Bacterium coli and Streptococcus faecalis were able to grow only over a narrow range of salt concentrations. 相似文献
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WINFRED E. BRENCHLEY D.Sc. 《The Annals of applied biology》1934,21(3):398-417
1. Comparisons have been made between the action of rubidium sulphate and palladium chloride on the growth of barley, wheat, oats peas and beans in complete nutrient solutions.
2. Over a wide range of concentrations rubidium sulphate was not found to exercise either a beneficial or a harmful action on the growth of any of the species tested. The germination of the seeds was likewise not affected.
3. No benefit was derived from palladium chloride , but at a comparatively low concentration a harmful action occurred which became more intense with increasing concentration. Stunting of the main root and laterals was a characteristic feature of this toxicity. With the lower concentrations the check was temporary, and the roots eventually made normal growth, as good as that in the control plants. With increasing amounts of pallahum chloride the poisoning effect became more persistent, until a concentration was reached which did not allow of any root or shoot recovery.
4. The tolerance of palladium varies with the species, as was indicated b. the measure of recovery. Barley appeared to be the least, and oats the most sensitive of the three cereals tested. Peas responded at much the same concentrations as barley, but broad beans made so complete a recovery from the initial checking that the dry weights were ultimately not reduced even by the strongest concentration tested, the plants being indistinguishable from the controls.
5. The effect of palladium poisoning was similar whether the seeds were germinated in the presence of palladium or whether the seedlings were not introduced to it until they were about a week old. 相似文献
2. Over a wide range of concentrations rubidium sulphate was not found to exercise either a beneficial or a harmful action on the growth of any of the species tested. The germination of the seeds was likewise not affected.
3. No benefit was derived from palladium chloride , but at a comparatively low concentration a harmful action occurred which became more intense with increasing concentration. Stunting of the main root and laterals was a characteristic feature of this toxicity. With the lower concentrations the check was temporary, and the roots eventually made normal growth, as good as that in the control plants. With increasing amounts of pallahum chloride the poisoning effect became more persistent, until a concentration was reached which did not allow of any root or shoot recovery.
4. The tolerance of palladium varies with the species, as was indicated b. the measure of recovery. Barley appeared to be the least, and oats the most sensitive of the three cereals tested. Peas responded at much the same concentrations as barley, but broad beans made so complete a recovery from the initial checking that the dry weights were ultimately not reduced even by the strongest concentration tested, the plants being indistinguishable from the controls.
5. The effect of palladium poisoning was similar whether the seeds were germinated in the presence of palladium or whether the seedlings were not introduced to it until they were about a week old. 相似文献
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采用岩棉和营养土方作育苗基质,观测了基质对番茄幼苗各时期生长的影响。其试验结果是：以岩棉作基质培育功苗能增加番茄幼苗全株的干重,其中幼苗根系的干重增加较为显著。在播种２４ｄ内,岩棉育苗的幼苗高度、茎干重、叶面积和干重的增长略低于营养土方育苗,２４ｄ以后,岩棉育苗则增长迅速,说明岩棉育苗具有增加幼苗干物质累积、培育壮苗的特点,证实岩棉是一种良好的育苗基质。 相似文献