不同光照条件下三七幼苗形态及生长指标的变化

用遮阳网设置不同透光率(自然全光照的1%、3%、8%、12%和22%)处理,对不同光照条件下三七〔Panax notoginseng(Burk.)F.H.Chen〕幼苗形态指标(株高、冠幅、块根长、主根长、块根直径、茎基径、单株须根数和单株须根长)、干物质积累(不同器官干质量)和分配以及叶片性状(单株叶面积、比叶面积和叶绿素相对含量SPAD值)的变化进行了研究。结果表明:在透光率不同的条件下三七幼苗的形态指标、不同器官干质量及分配以及叶片性状均有明显变化。其中,块根直径、单株须根长、单株须根数、不同器官(块根、须根、根、叶片和茎)干质量和植株总干质量均随透光率增大逐渐提高;株高在透光率22%条件下最高;冠幅和单株叶面积在透光率3%条件下最大;主根长、茎基径、根冠比、根质比及SPAD值均在透光率8%条件下最高;茎质比和叶质比在透光率3%和1%条件下较大;比叶面积随透光率增大逐渐降低。综合分析结果揭示:三七是一种典型的喜阴植物,种植过程中适当遮阳有利于其生长和干物质积累,其中透光率8%对三七幼苗生长较为适宜。

Change in morphological and growth indexes of Panax notoginseng seedling under different light conditions

Different transmittance （1%, 3%, 8%, 12% and 22 % of full sunlight） treatments were set up by shading net, and on the basis, changes in morphological indexes （ plant height, crown width, root tuber length, main root length, root tuber diameter, stem base diameter, number and length of fibrous root per plant ） , dry matter accumulation （ dry weights of different organs ） and allocation, and leaf characters （ leaf area per plant, specific leaf area and SPAD value of relative chlorophyll content） of Panax notoginseng （ Burk.） F. H. Chen seedling were studied under different light conditions. Results show that there are obvious changes in morphological indexes, dry matter accumulation and allocation of different organs, and leaf characters under different transmittances. In which, root tuber diameter, length and number of fibrous root per plant, dry weight of different organs （ including root tuber, fibrous root, root, leaf and stem ） and total dry weight of individual all increase gradually with enhancing of transmittance;plant height is the highest under 22% of transmittance; crown width and leaf area per plant are the biggest under 3% of transmittance;main root length, stem base diameter, root-shoot ratio, root mass ratio and SPAD value are the highest under 8% of transmittance; both of stem mass ratio and leaf mass ratio are higher under 3% and 1% of transmittances; and specific leaf area reduces gradually with enhancing of transmittances. Result of comprehensive analysis suggests that P. notoginseng is a typical shade-tolerance species, and appropriate shading is beneficial to its growth and dry matter accumulation, in which, 8% of transmittance is suitable for its seedling growth.