卢亚莉 张世鑫 王真辉 田维敏 史敏晶

摘  要：通過割胶，巴西橡胶树树皮中收集的胶乳被制成天然橡胶。橡胶树树皮的结构在天然橡胶的生产中具有重要地位。死皮是影响天然橡胶产量的重要因子之一，目前对死皮橡胶树树皮结构系统的研究较少。以无性系‘RY7-33-97健康树、三级死皮树和五级死皮树树皮为研究材料，利用光学显微技术，对不同级别、不同死皮程度树皮中的乳管、筛管、石细胞、单宁等的形态结构等进行了研究。结果表明：随着死皮程度的增加，乳管排列逐渐紊乱，不易统计列数;膨大乳管的列数显著增多，从最早出现的砂皮层逐步深入至水囊皮;乳管染色变浅为黄色，甚至出现中空;与直径高达40 ?m的膨大乳管相比，有效乳管的直径通常不足20 ?m，且死皮严重情况下，其直径会进一步减小。筛管的直径在死皮时会发生减小，尤其是树皮不排胶的部位尤为明显。随死皮程度增加，石细胞不仅数量增多，并且形成的位置明显内移，甚至可深达水囊皮，靠近形成层。单宁细胞在树皮中数量随死皮程度增强而逐渐增多，且在水囊皮等幼嫩组织中增加较明显。本研究对比健康树，分析了三级和五级死皮树树皮中多种组织的结构特征，旨在为阐明橡胶树死皮的发生机理提供依据，为死皮防治技术的研发奠定基础。

关键词：橡胶树;死皮;树皮结构;乳管;单宁

中图分类号：S794.1      文献标识码：A

Bark Structure of the Clone ‘RY7-33-97 with Different Level of Tapping Panel Dryness （TPD） in Rubber Tree （Hevea brasiliensis Muell. Arg.）

LU Yali， ZHANG Shixin， WANG Zhenhui， TIAN Weimin， SHI Minjing*

Rubber Research Institute， Chinese Academy of Tropical Agricultural Sciences / Key Laboratory of Biology and Genetic Resources of Rubber Tree of Ministry of Agriculture and Rural Affairs / State Key Laboratory Incubation Base for Cultivation and Physiology of Tropical Crops Rubber Research Institute， Haikou， Hainan 571101， China

Abstract： Natural rubber is extracted from latex that collected from the bark of rubber trees by tapping. The structure of bark plays an important role in the production of natural rubber. Tapping panel dryness （TPD） is one of the key factors to affect yield of rubber trees， but the mechanism of TPD was still less known and the change of bark structure of TPD was rarely studied. By using the optical microscopy technology， the morphological structure and location of laticifer， sieve tube， tannin cell and stone cell in the bark of ‘RY7-33-97 with different level of TPD were studied. Compared to the healthy rubber tree， the bark structure in the third and the fifth grade of TPD tree changed obviously. Accompanying the increase of TPD extent， the number of laticifer lines was difficult to be counted for the disordered arrangement. The swell laticifer appeared gradually inward to cambium from sandy skin. Besides the abnormal swelling and light dying， hollow laticifer also was observed. The diameter of swell laticifer was up to 40 ?m， but the effective laticifer usually was short of 20 ?m and even smaller when TPD aggravated. The diameter of sieve tube decreased obviously under the condition of non-latex flow. Stone cells formed largely in the yellow skin and even went deeply into the water sac skin and the cambium in TPD rubber tree. The number of tannin cells increased obviously when TPD happened， especially in the tender tissue such as water sac skin. This study would lay a foundation for illu-minating the mechanism of TPD and provide a theoretical basis for developing the prevention technology of TPD in rubber trees.

Keywords： Hevea brasiliensis Muell. Arg.; tapping panel dryness （TPD）; bark structure; laticifer; tannin

DOI： 10.3969/j.issn.1000-2561.2021.07.014

巴西橡胶树（简称橡胶树）是目前唯一生产具有商业价值天然橡胶的栽培作物[1-2]。……