Leaf number, dry weight, and nutrient composition of Lactuca sativa L. cv. Waldmann's Green leaves were compared following 9 days of treatment in a controlled environment room under various combinations of photosynthetic photon flux (PPF:350 vs 800 micromoles m-2 s-1), atmospheric CO2 level (ambient vs 1500 micromoles mol-1), and single-strength (1X:15 mM) vs double-strength (2X:30 mM) nitrogen (N) as NO3- alone or as NH4(+) + NO3- (1:5 molar ratio). CO2 enrichment greatly enhanced leaf number under all PPF and N conditions, but increased leaf dry weight only at high PPF. Conditions favoring high photosynthesis enhanced leaf starch content 3-fold, and protein content increased as much as 64% with 2X NH4(+)+NO3-. Free sugar content was 6 to 9% of leaf dry weight for all treatment combinations, while fat was 1.5 to 3.5%. Ash content varied from 15 to 20% of leaf dry weight. Modified controlled environments can be used to enhance the nutritional content as well as the yield of crops to be used for life support in space-deployed, self-sustaining human habitats. Leaf lettuce is a useful model crop for demonstrating the potential of nutritional value added by environmental manipulation.

中文翻译：

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产量和营养成分的环境改良？Waldmann's Green？生菜

Lactuca sativa L. cv. 的叶数、干重和营养成分。在受控环境室中处理 9 天后，在光合光子通量（PPF：350 对 800 微摩尔 m-2 s-1）、大气 CO2 水平（环境对 1500 微摩尔 mol-1）、和单强度 (1X:15 mM) 与双强度 (2X:30 mM) 氮 (N) 作为单独的 NO3- 或作为 NH4(+) + NO3-（1:5 摩尔比）。在所有 PPF 和 N 条件下，CO2 富集大大增加了叶数，但仅在高 PPF 下增加了叶子干重。有利于高光合作用的条件使叶淀粉含量增加了 3 倍，蛋白质含量在 2X NH4(+)+NO3- 下增加了 64%。所有处理组合的游离糖含量为叶干重的 6% 至 9%，而脂肪含量为 1.5% 至 3.5%。灰分含量为叶片干重的 15% 至 20%。改进的受控环境可用于在太空部署的、自给自足的人类栖息地中提高营养成分以及用于维持生命的作物的产量。叶生菜是一种有用的模式作物，用于证明通过环境操作增加营养价值的潜力。