农林复合系统中滇龙胆形态和生物量变化研究

Variation for morphology and biomass of Gentiana rigescens in agroforestry system

关键词:  农林系统  滇龙胆  形态  生物量  变化

Key words:  agroforestry system  Gentiana rigescens  morphology  biomass  variation

摘要:

以幼龄茶树(Camellia sinensis var. sinensis)、十年茶树、木瓜(Chaenomeles sinensis)、尼泊尔桤木(Alnus nepalensis)、大叶桉(Eucalyptus robusta)间作模式和荒坡栽培滇龙胆为研究对象,测定其株高、茎粗、叶长、根粗、生物量等性状,采用单因素方差分析、多重比较、相关性分析和多元逐步回归分析对其形态和生物量数据进行分析。结果表明:荒坡栽培、滇龙胆与十年茶树间作其株高最高,为(37.32±8.36)cm和(37.31±9.62)cm,与大叶桉间作其株高最低,为(19.08±12.40)cm; 荒坡栽培植株茎粗数值最高,为(0.36±0.13)cm,大叶桉间作茎粗数值最低,为(0.23±0.04)cm; 与茶树间作植株根系最长,为(18.42±7.23)cm和(17.71±7.34)cm,与尼泊尔桤木间作植株须根数最少,为(7.32±2.23)cm; 根粗受栽培模式影响不显著(P>0.05); 荒坡栽培全株生物量最高,为(14.52±13.37)g,大叶桉间作全株生物量最低,为(2.17±1.42)g。相关性分析显示,株高、茎粗和须根数与全株生物量呈极显著的正相关(R=0.514,P<0.01; R=0.510,P<0.01; R=0.339,P<0.01)。根茎比与全株生物量呈极显著的负相关(R=-0.295,P<0.01)。多元逐步回归分析显示,各性状对全株生物量的积累贡献程度不同,株高、茎粗、须根数和根粗是影响滇龙胆生物量积累的主要性状。荒坡栽培光照条件较好,有利于植株生物量的积累; 与桉树间作,滇龙胆可能受生物与非生物胁迫的共同影响,使其植株矮小,生物量偏低。6种栽培模式中荒坡、滇龙胆与茶树、木瓜间作栽培为高产模式。研究结果可为农林药用复合种植中物种搭配、时间和空间种植技术优化升级以及管理提供理论依据。

Abstract:

Environment and species composition affect crops yield of agroforestry system. The aim of the present study was to investigate the influence of different cultivation systems on morphological traits and biomass of the traditional medicinal plant Gentiana rigescens, and to provide a theoretical basis for management of multiple cropping of medicinal plants. All the samples were collected from six cultivation systems, G. rigescens-Camellia sinensis var. sinensis (young tea trees), Gentiana rigescens-Camellia sinensis var. sinensis(ten years old tea trees), Gentiana rigescens-Chaenomeles sinensis, Gentiana rigescens-Alnus nepalensis, Gentiana rigescens-Eucalyptus robusta systems and monoculture(Gentiana rigescens grown on the slope of the valley). Stem height, stem diameter, leaf length, root diameter and biomass etc. were measured and recorded at the individual level. The statistically significant differences of the traits of G. rigescens collected from six cultivation systems were analyzed by one-way ANOVA and student-newman-keuls test. Correlation analysis and multiple linear stepwise regression analysis were used to study relationships between morphological traits and biomass. The results showed that the stem height were the highest in monoculture and G. rigescens-Camellia sinensis var. sinensis (young tea trees)systems,(37.32±8.36)cm and(37.31±9.62)cm, respectively. The lowest stem height was(19.08±12.40)cm which was found in Gentiana rigescens-Eucalyptus robusta system. The stem diameter ranged from(0.36±0.13)cm in monoculture to(0.23±0.04)cm in Gentiana rigescens-Eucalyptus robusta system. The highest values of root length were found in the samples intercropped with young tea trees and ten years old tea trees, respectively, whereas the lowest value was found in the samples intercropped with Alnus nepalensis. There was no significant difference of root diameter values among six cultivation systems(P<0.05). However, the highest biomass was found in monoculture system while the lowest in Gentiana rigescens-Eucalyptus robusta system. Correlation analysis displayed that stem height, stem diameter and fibrous root number had very significant positive correlations with the biomass, respectively(R=0.514, P<0.01; R=0.510, P<0.01; R=0.339, P<0.01). But root length/stem length had very significant negative correlation with biomass(R=-0.295,P<0.01). Multiple linear stepwise regression analysis showed that different morphological traits had different contribution for biomass accumulation. Stem high, stem diameter, fibrous root number and root diameter were key traits for the accumulation of biomass under six cultivation systems. Monoculture system could improve better light condition for the growth and biomass accumulation of Gentiana rigescens than other cultivation systems. However, plant intercropped with Eucalyptus robusta had the lowest values of biomass and stem height. It may be affected by biotic and abiotic stresses. Monoculture, Gentiana rigescens-Camellia sinensis var. sinensis and Gentiana rigescens-Chaenomeles sinensis systems were the high yield cultivation systems for Gentiana rigescens. All the results of the study provided useful information for species mix in agroforestry system and development of cultivation techniques.