褐皮病橡胶树休割期病害径向扩展的超微结构研究

光学和透射电子显微镜观察证实了褐皮病橡胶树在休割期间病害能够从老的病组织沿着径向扩展到形成层新产生的组织。在病害扩展过程中乳管最先表现出症状。感病乳管最初可见的超微结构症状是:除了一些橡胶粒子原位凝固外,还形成相当多的髓鞘状结构和在细胞核中出现细纤维。作者认为,关于橡胶树褐皮病的起因和扩展机制的流行观点很难解释这种休割褐皮病树的径向扩展。

ULTRASTRUCTURE OF RADIAL EXTENSION OF BROWN BAST IN DISEASED HEVEA IN RESTING

The histological and cytological observations demonstrate that brown bast could spread from the diseased tissues to the new tissues produced by cambium in diseased Hevea brasiliensis in resting.In the cource of its spreading,the disease symptoms appeared first in the laticifers of the newly-produced tissues. The first visible symptoms on the ultrastructure of the affected latieifers were the occurence of a considerable amount of myelin-like structures and the appearance of the fine fibrils in the nucleus in addition to the coagulation in situ of some rubber particles. We believe that the radial extension of brown bast in rested diseased-trees is hard to be explained by current views on the causes and the extension mechanisms of the disease.