海南鹧鸪茶主要农艺性状的形态学、细胞学及遗传学特征研究

Mallotus. Oblongiolus(Miq.) Mull.-Agr., a species of Mallotus in Spurge Family, is a strong local characteristics and ethnic characteristics of the beverage plants substituting-for-tea and national medicinal plant in Hainan. It has obvious effects such as anti-inflammatory, liver, gallbladder, promoting digestion and reconciliation greasiness. But our prvious research found a greater difference about the main agronomic traits of Mallotus. Oblongiolus such as gender, flowering and fruit, leaf color and aroma components. There are also controveraial problem about the aroma of origin. In this application project, Micro-morphological characteristics of leaf epidermis for Mallotus. Oblongiolus will be examined with an optical microscope and SEM., morphological data will be obtained. The genetic basis of Mallotus. Oblongiolus will be announced by using cytological marking technology, selection of different populations of root tip, with wall degradation hypotonic technique and investigating their karyotype, analyzing the genetic structure and differentiation degree by using ISSR and SRAP marks on the molecular level, the inner quality will be announced content of main aroma components by detection and analysis on different leaf color and different populations by GC-MS method. The correlation were used for statistical analysis, such as the main aroma component content and chromosome karyotype, genetic structure and differentiation, phenotype etc. The theory basis will be provided for the species screening and comprehensive development and utilization on Mallotus. Oblongiolus by the genetic mechanism (cytological, molecular and phenotypic level) the formation mechanism of Mallotus. Oblongiolus main agronomic characters of systematic research.

鹧鸪茶是海南的一种具有浓郁地方特色和民族特色的代茶饮料植物和民族药用植物，具有明显的消炎、利肝、利胆、助消化和解油腻等功效。但我们前期工作发现，有关鹧鸪茶的性别、花期与果期、叶色、香味等主要农艺性状的描述与经典植物学专著有较大区别，香味的成因也有较大争议。本项目利用光学显微镜和扫描电镜对其居群叶表皮微形态特征进行观察，获取形态数据。利用细胞学标记技术，选用不同居群鹧鸪茶材料根尖，采用去壁低渗技术，探讨鹧鸪茶染色体核型，揭示其遗传基础；利用ISSR、SRAP等标记手段，从分子水平方面，分析其遗传结构和分化程度；应用GC-MS法分析测试不同叶色、不同居群等主要香味成分的含量，揭示其内在质量。对主要香味成份含量与染色体核型、遗传结构和分化、表型的相关性进行统计分析，从遗传机制（细胞学、分子和表型水平）对鹧鸪茶主要农艺性状的形成机理进行系统研究，为鹧鸪茶优良种源筛选和综合开发利用提供理论依据。

鹧鸪茶具有明显的消炎、利肝胆、助消化和解油腻等功效，然而鹧鸪茶的主要农艺性状存在较大的争议。本研究结果如下：.1.野生鹧鸪茶存在三种性别特征，即雌株、雄株和雌雄同株。.2.不同居群的鹧鸪茶茎的周皮组织细胞排列紧凑，近似长方形；皮层细胞层数有2～4层厚角组织，厚度均值变化范围：表皮34.199μm～6.498μm，皮层75.091μm～42.697μm，韧皮部91.876μm～34.542μm，木质部319.058μm～46.291μm，髓结构264.791μm～101.087μm。.3.不同居群的鹧鸪茶茎的皮层细胞层数有2～4层厚角组织，厚度均值变化范围：表皮34.199μm～6.498μm，皮层75.091μm～42.697μm，韧皮部91.876μm～34.542μm，木质部319.058μm～46.291μm，髓结构264.791μm～101.087μm。.4.不同居群的鹧鸪茶根由周皮、薄壁组织、韧皮部、木质部4大组织构成。鹧鸪茶根的周皮组织由多层皮层细胞紧密排列而成，呈长条形或棒状，细胞长度不均。中柱鞘组织较为发达，导管口径较大，有明显的韧皮射线，与导管平行向外散发。厚度均值变化范围：周皮26.623μm～6.545μm，韧皮部100.449μm～27.438μm，木质部586.176μm～126.236μm，韧木比为0.498～0.074。.5.20个供试野生鹧鸪茶居群的ISSR和SRAP结果显示：遗传分化主要存在于居群内，居群间（ISSR的Gst＝0.2709，SRAP的Gst＝2764）的遗传分化较弱，鹧鸪茶居群的基因流为1.346（ISSR）与1.3092（SRAP）。.6.GC-MS发现不同叶色鹧鸪茶主要香味成分的组成(红30种、绿32种)和相对百分含量差异显著；如：石竹烯(红22.59%、绿15.85%)、律草烯(红20.86%、绿1.97%)、可巴烯(红3.04%、绿10.02%)、α-荜澄茄油烯(红1.48%、绿7.70%)等。.7.GC-MS从20个野生鹧鸪茶居群中检出193种化合物。其相对百分含量：荜澄茄油烯（1.16~6.85%）；α-愈创木烯（0.96~6.97%）；Α-可巴烯（3.23~11.34%）；乙位石竹烯（0.00~20.25%）；香橙烯（0.00~7.49%）等。这些研究结果为鹧鸪茶优良种源筛选和综合开发利用提供理论依据。