Welcome to Chinese Journal of Tropical Crops,

Chinese Journal of Tropical Crops ›› 2021, Vol. 42 ›› Issue (7): 1918-1924.DOI: 10.3969/j.issn.1000-2561.2021.07.014

• Plant Cultivation, Physiology & Biochemistry • Previous Articles     Next Articles

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*()   

  1. 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
  • Received:2020-05-19 Revised:2020-09-17 Online:2021-07-25 Published:2021-08-05
  • Contact: SHI Minjing

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 µm, but the effective laticifer usually was short of 20 µm 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 illuminating the mechanism of TPD and provide a theoretical basis for developing the prevention technology of TPD in rubber trees.

Key words: Hevea brasiliensis Muell. Arg., tapping panel dryness (TPD), bark structure, laticifer, tannin

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