光强和施氮量对催吐萝芙木生长及生物量的影响

通过不同光强(15%、40%和70%自然光强)和施氮量(15g·株-1、30g·株-1和60g·株-1)的盆栽试验,研究了不同光照强度和施氮量对催吐萝芙木生长和生物量的影响。结果表明:光强和施氮量显著影响催吐萝芙木的生长、单株生物量及生物量分配(P0.05)。在70%自然光强下,催吐萝芙木株高、地径、株高和地径的相对生长速率(RGRH,RGRD)、单株生物量都较15%和40%自然光强下高,并分配更多的生物量到地下部分。在15%和40%自然光强下,催吐萝芙木的株高、地径、RGRH、RGRD、单株生物量随施氮量的增加而减小;在70%自然光强下,催吐萝芙木在30g·株-1中等施氮量下生长最好,单株生物量最大,达559.6g·株-1。在相同光强下,催吐萝芙木根生物量比(RMR)和根冠比(R/S)随施氮量增加而减小,比叶面积(SLA)和叶生物量比(LMR)在低光强和高施氮量下最大。从株高、地径、RGRH、RGRD、单株生物量、RMR和R/S等指标看,70%自然光强和30g·株-1的施氮量是催吐萝芙木最佳的光强和施氮量组合。

Effect of light intensity and nitrogen level on growth and biomass of Rauvolfia vomitoria

A potted experiment was conducted to study the growth and biomass of Rauvolfia vomitoria plant under different light intensities (15%, 40% and 70% of full sunlight) and nitrogen levels (15 g, 30 g and 60 g per plant). The results show that the growth, individual biomass and biomass allocation are significantly influenced by light intensity and nitrogen level (P<0.05). The plant height, ground diameter, relative growth rate of height and ground diameter (RGR_H, RGR_D) and individual biomass under 70% light intensity are higher than those under 15% and 40% light intensity, and more biomass is allocated to underground plant part. The height, ground diameter, RGR_H, RGR_D and individual biomass decrease with increasing nitrogen level under 15% and 40% light intensity. Under 70% light intensity, R. vomitoria plant grows best and individual biomass reaches the highest value of 559.6 g at 30 g nitrogen per plant. At the same light intensity, root mass ratio (RMR) and root to shoot ratio (R/S) decrease with increasing nitrogen level. On the other hand, specific leaf area (SLA) and leaf mass ratio (LMR) are highest at 15% light intensity and 60 g nitrogen per plant. Analysis on individual biomass, RMR, R/S and growth characteristics including height, ground diameter, RGR_H, RGR_D reveals that 70% light intensity and 30 g nitrogen per plant combination yields the optimum condition for R. vomitoria plants.