氮添加对二年生三七生长、光合特性及皂苷含量的影响

生态学杂志

氮添加对二年生三七生长、光合特性及皂苷含量的影响

寸竹^1,2,3,张金燕^1,2,3,陈军文^1,2,3*

(¹云南农业大学西南中药材种质创新与利用国家地方联合工程研究中心，昆明 650201； ²云南农业大学云南省药用植物生物学
重点实验室，昆明 650201； ³云南农业大学农学与生物技术学院，昆明 650201)

发布日期:2020-04-10

Effects of nitrogen addition on growth, photosynthetic characteristics and saponin content in two-year-old Panax notoginseng.

CUN Zhu^1,2,3, ZHANG Jin-yan^1,2,3, CHEN Jun-wen^1,2,3*

(¹National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming 650201, China; ²The key Laboratory of Medicinal Plant Biology of yunnan Province, Yunnan Agricultural University, Kunming 650201, China; ³College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming 650201, China).

Published:2020-04-10

摘要/Abstract

摘要： 为探究氮素对药用植物三七\[Panax notoginseng (Burkill) F. H. Chen\]生长、光合特性及皂苷含量的影响，从而为氮肥合理施用提供理论依据，通过盆栽试验，研究不同氮添加水平(低氮0 kg·hm^-2，LN；中氮225 kg·hm^-2，MN；高氮450 kg·hm^-2，HN)对二年生三七叶片解剖结构、根系形态特征、生物量、光合效率及皂苷含量的影响。结果表明：三七叶片的上表皮厚度、下表皮厚度、栅栏组织厚度和海绵组织厚度在HN水平下最大，总根长、主根长、根系表面积、须根数、须根长、根长密度、根质比、根冠比和比叶面积在LN水平下最大，MN水平根系活力显著高于其他氮素水平（P<0.05）；光响应和CO₂响应过程中，MN处理的净光合速率、最大光合速率、羧化速率、最大电子传递速率和最大羧化速率均显著高于其他处理（P<0.05）；单位叶面积氮含量、叶绿素含量和叶氮在光合组织中的分配量在HN处理下最大；光合氮素利用率在LN水平下最高，根部总氮含量在MN处理下最高；三七根的皂苷含量在HN处理下最低。缺氮和高氮均不利于三七生长，光合效率均降低，缺氮下的叶片变薄和高氮下的叶片增厚均能抑制CO₂的扩散；缺氮条件下，需产生更多保护自身生存的皂苷类防御物质；氮富余条件下，C/N比减少，则削弱皂苷的生物合成。

Abstract: To provide a theoretical basis for rational fertilization, we explored the effects of different nitrogen (N) levels on growth, photosynthetic characteristics and saponin content of medicinal plants Panax notoginseng. Pot experiments were conducted to investigate leaf anatomy, root morphological characteristics, biomass, photosynthetic efficiency and saponin content in two-year-old P. notoginseng treated with different nitrogen levels (0 kg·hm^-2, LN; moderate nitrogen, 225 kg·hm^-2, MN; high nitrogen, 450 kg·hm^-2, HN). The results showed that the thickness of upper epidermis, lower epidermis, palisade tissue and sponge tissue reached the highest value in the HN individuals. Total root length, main root length, root surface area, number of fibrous roots, root length, root length density, root mass ratio, root shoot ratio and specific leaf area reached the maximum value in the LN individuals. Root system activity was significantly higher in the MN individuals than in the other two treatments (P<0.05). With respect to the responses of photosynthesis to light and CO₂ level, net photosynthetic assimilation, maximum photosynthetic assimilation at saturating light, carboxylation efficiency, maximum electron transfer rate and maximum carboxylation efficiency of MN individuals were significantly higher than those in the other two treatments (P<0.05). Nitrogen content per unit leaf area, chlorophyll content and the allocation of leaf N to photosynthetic tissues were highest in the HN treatment. Photosynthetic N use efficiency was the highest in the LN treatment, and total N content in roots was the highest in the MN treatment. Saponin content in roots of P. notoginseng was the lowest in the HN treatment. N surplus or N deficiency is unfavorable to growth and photosynthetic performance ofP. notoginseng. Decreased leaf thinness under LN or increased leaf thickness under HN treatment would inhibit CO₂ diffusionin leaves. Under N deficiency, more saponinlike defensive compounds are needed for the survival of P. notoginseng. Under excessive N condition, saponin biosynthesis is weakened due to lower C/N ratio.

寸竹,张金燕,陈军文. 氮添加对二年生三七生长、光合特性及皂苷含量的影响[J]. 生态学杂志.

CUN Zhu, ZHANG Jin-yan, CHEN Jun-wen. Effects of nitrogen addition on growth, photosynthetic characteristics and saponin content in two-year-old Panax notoginseng.[J]. cje.