不同透光率对三七生长特征及根皂苷含量的影响

Effects of light transmittance on plant growth and root ginsenoside content of Panax notoginseng

为明确光照强度对药用作物一年生和二年生三七[Panax notoginseng(Burk)F.H.Chen]形态特征、生物量积累和分配以及皂苷积累的影响,为三七优质、高效栽培提供理论依据,采用搭建不同透光率遮荫棚的方法对三七进行人工遮荫,荫棚透光率分别为22.3%、11.8%、8.4%、2.9%和1.1%,在三七收获期分别测定植株的形态指标、生物量以及皂苷含量.结果显示:当透光率在22.3%-2.9%之间时,透光率降低对一年生三七各器官生物量无显著性影响,但当透光率降低到1.1%时,各器官生物量显著降低;在透光率为1.1%的条件下,一年生三七根冠比和根质比显著减小,茎质比和叶质比显著增大.二年生三七根生物量在透光率为22.3%、11.8%、8.4%和2.9%的条件下无显著差异,在透光率为1.1%的条件下显著降低.透光率为11.8%的条件最有利于一年生和二年生三七根系的健康生长;但一年生三七根总皂苷含量在透光率为22.3%的条件下最高(质量分数w=0.862%),二年生三七总皂苷含量在透光率为8.4%的条件下最高(质量分数w=5.642%).总的来看,三七是一种典型的喜阴根茎类药用植物,适当遮荫有利于其生长及皂苷的积累;10%左右的透光率应是三七生产中首选的生长环境光照强度.

In order to provide a scientific basis for efficient and high-quality cultivation of medicinal crop Panax notoginseng,we examined the morphology, biomass accumulation and allocation, as well as root ginsenoside accumulation in P. notoginseng grown along artificial light gradients. Seeds and one-year-old rootstocks were firstly sowed in nursery bed. After the seedlings came out evenly, healthy seedlings were transplanted into five screen houses where light intensity was 22.3%, 11.8 %, 8.4%, 2.9% and 1.1% of full sunlight, respectively. The morphology, biomass accumulation and allocation, and ginsenoside content ofP. notoginseng were analyzed during the harvest period. The results showed no significant differences of root, stem, and leaf biomass ofP. notoginseng among 22.3% to 2.9% of full sunlight, but significant decrease under 1.1% of full sunlight. Under 1.1% of full sunlight, the root/shoot ratio and root/biomass ratio significantly decreased, but the stem/biomass ratio and leaf/biomass ratio increased. The biomass of two-year-old P. notoginseng showed no significant differences among 22.3%, 11.8%, 8.4% and 2.9% of full sunlight, but significant decrease under 1.1% of full sunlight. Root of one- and two-year-old P. notoginseng grew vigorously under 11.8% of full sunlight. Ginsenoside content in one-year-old P. notoginseng reached a maximum value （w = 0.862%） under 22.3% of full sunlight, but the maximum value （w = 5.642%） of that in two-year-old P. notoginseng was under 8.4% of full sunlight. In conclusion, P. notoginseng is a typical shade-tolerant medicinal crop species; appropriate shading will facilitate its growth and ginsenoside accumulation; light intensity of about 10% of full sunlight is preferred for the production ofP. notoginseng.