MINERAL REQUIREMENTS OF LEMNA MINOR

作者：Robert Aaron Steinberg · 发表于：PLANT PHYSIOLOGY · 年份：1946 · DOI：10.1104/pp.21.1.42 · 被引用次数：90 · 研究领域：Botany and Plant Ecology Studies

The use of Lemna minor Link as a test organism for the micronutrient requirements of the higher plants was undertaken by the writer as a check on similar data with the fungus Aspergillus niger v. Tiegh. It was possible to demonstrate that the macroand micronutrient needs of both were similar, except that Lemna also required calcium and boron (1). The mineral and acidity requirements of Lemna were identical with those of other higher green plants. In Lemna cultures with fixed, minimal quantities of salts, the ratio of yield to total macronutrient salts was 0.9, a value termed efficiency of salt utilization*' by the writer. This corresponded to a total of 1,113 mg. of macronutrients per gram of yield, each salt of the nutrient solution having been adjusted to be at the experimental minimum for maximum yield. Addition of 0.5 per cent, sucrose, nevertheless, increased the ratio to 2.3 though the quantity of salts remained unaltered. The macronutrient salt requirement was thereby decreased to 434 mg. per gram of yield. Aspergillus, however, reaches an efficiency of 9.6, which is equivalent to 106 mg. salts per gram. The lower efficiency of Lemna may be intrinsic but might be only a reflection of secondary requirements, such as buffering of the nutrient solution and insufficient energy (low photosynthesis) for efficient absorption. An effort has been made to obtain an improvement in the results previously reported. Numerical data on the effects of copper are also included.