栽培密度和施肥水平对黄花蒿生长特性和青蒿素的影响

采用大田试验，研究不同密度和施肥水平对黄花蒿生长、生物量分配和青蒿素含量的影响。试验设3个密度水平: 高密度（111111株/hm2）、中密度（55555株/hm2）和低密度（27778株/hm2）。 各密度设3个施肥水平(复合肥，N-P2O5-K2O为15-15-15): 不施肥、低肥（60 kg/hm2）和高肥（120 kg/hm2）。结果表明，黄花蒿对密度和养分条件变化的适应性较强，其中密度是植株大小、生物量分配和产量有关参数的主要决定因子，而青蒿素含量由施肥水平决定。相同施肥水平下，黄花蒿的基径与分枝数均随密度的降低而显著增大，其单株生物量也随密度的降低而显著增大； 中、高密度黄花蒿的支持结构生物量分数均显著大于低密度，低密度黄花蒿的根生物量分数和根/冠比显著大于中、高密度。相同密度下，施肥水平对黄花蒿的单株生物量影响不显著，但显著影响其生物量分配。低密度下，黄花蒿根生物量分数和根/冠比随施肥水平的增高而显著降低； 高密度下，黄花蒿叶生物量分数随施肥水平的增高而显著增大。所有处理中，低密度低施肥水平黄花蒿的青蒿素含量最高，中密度低施肥水平的叶产量和青蒿素产量最大。本试验条件下，黄花蒿栽培以密度55555株/hm2、 施肥60 kg/hm2为宜。

Effects of planting density and fertilization on growth characters and artemisinin of Artemisia annua L.

Field plot trials were carried out to study the effects of different planting densities and fertilization levels on Artemisia annua growth, biomass allocation and artemisinin content. A. annua was grown at three densities, namely high density (111111 plants/ hm²), intermediate density (55555 plants/ hm²) and low density (27778 plants/ hm²). There were three levels of compound fertilizer (0, 60 and 120 kg/ hm²) for each density. The results show that A. annua is very flexible in response to the planting densities and nutrient availabilities, and the planting density is the main factor affecting the parameters related to the plant size, biomass allocation and yield, while artemisinin content is determined by the fertilizer levels. The biomass per plant, basal diameter and branch numbers of A.annua are significantly increased with decrease of the planting density. The root mass fraction and ratio of the root mass to crown mass under the low planning density are significantly higher that those under the intermediate and high planting densities. In each planting density treatment, the biomasses per plant of A. annua are not significantly changed under the different fertilizer levels, while the biomass allocations of A. annua are significantly changed. Under the low planting density, the root mass fraction and root mass/crown mass are significantly increased with decrease of the fertilizer levels, and under the high planting density, the leaf mass fractions are significantly increased with increase of the fertilizer levels. Among all the treatments, the artemisinin content of A.annua is highest under the low planting density and the low fertilization, the leaf biomass and artemisinin yield are highest under the intermediate density and the low fertilization. In summary, the optimal density and fertilizer treatment are 55555 plants/ hm² and N 60 kg/ hm² in the experiment.