矿质营养与沙冬青幼苗生长和根系结瘤关系的研究

该文以珍珠岩为栽培介质，研究了在缺少N、P、K、Ca、Mg、Fe及其他微量元素情况下，幼苗的生长状况及其相应的形态特征.结果表明:缺少N、P、K时，幼苗在株高、茎粗、叶绿素含量、干重等生长指标上均与对照差异极其显著，同时在形态特征上表现出各自典型的缺素症状.其他元素则对其生长影响不明显，但对叶色有较大影响.此外，人工接种根瘤菌时，研究了不同N素水平对幼苗生长和根系结瘤的影响.结果显示，在N素水平为0 mol/L时，平均结瘤量达28个/株；0003 75 mol/L下仅8个/株；高于0007 5 mol/L，则无根瘤出现.对生长量的分析表明，幼苗生长与N素水平成正相关；低N水平下人工接种根瘤菌可以促进幼苗生长. 

Relationship between mineral nutrition and seedling growth as well as nodulation of Ammopiptanthus mongolicus

Taking perlite as the potted medium, seedling growth and its morphological characteristics were studied when N, P, K, Ca, Mg, Fe and other trace elements were lacking in a nutrition liquid. Results showed that seedlings lacking in N, P, K showed notable differences, in comparison with full nutrition, in the indices of seedling growth, including plant height, stem diameter, chlorophy content and dry weight. Typical nutrient deficiency symptoms showed up in morphological characteristics. In addition, the effects of different N levels on seedling growth and nodulation were studied when seedlings were inoculated with rhizobia . At the level of 0 mol/L, the average number of root nodules reached 28 for each plant; at 0.003 75 mol/L level, it was only eight on average; at 0.007 5 mol/L level, there were no nodules. Results showed that seedling growth is positively correlatied with N levels. Furthermore, inoculating rhizobia can promote seedling growth in the soil with low level of N.