Behaviour of <i>Xanthomonas citri</i> (Hasse) Dowson and Histological Changes of Diseased Tissues in the Process of Lesion Extension

DOI JASI Web Site

Bibliographic Information

Other Title
  • カンキツかいよう病の病はん拡大過程における病原細菌の行動とり病組織の変化
  • カンキツかいよう病の病斑拡大過程における病原細菌の行動と罹病組織の変化
  • カンキツ カイヨウビョウ ノ ビョウハン カクダイ カテイ ニ オケル ビョウ

Search this article

Abstract

Bacterial population and histological changes during the lesion extension of citrus canker were examined with regard to host resistance. On susceptible plants, lesion developed rapidly for an extended period of time. In the early stage of lesion development, the central part of the lesion became extremely hypertrophic, and abundant bacterial masses were observed in the hypertrophic tissue spreading into intercellular spaces of the peripheral non-hypertrophic tissues. In the process of lesion enlargement, hypertrophic cells were disintegrated gradually, starting from the central part of the lesion, by the action of the causal bacteria. Bacterial multiplication was markedly enhanced for a time accompanied by disintegration of the cells. In the later stage of lesion extension, bacterial multiplication seemed to be inhibited at the peripheral parts of the lesion, and bacterial masses were enclosed gradually with cell layers divided irregularly. On resistant plants, lesion extension was slow and both populations of hypertrophic cells and bacteria were always less. The host response such as irregular cell divisions and enclosure of bacteria with cell layers occurred more rapidly, and lesion extension was inhibited at an earlier stage than in the case of susceptible plants. In the later stage of lesion extension, hypertrophic cells became necrotic followed by disintegration, and few bacteria multiplied there. After the extinction of bacteria in the diseased tissues, meristematic tissue which looks like cork cambium surrounded the disintegrated tissue, restricting lesion extension. Exudation of bacteria from lesions on susceptible plants continued for a longer period at a higher level during lesion extension than that on resistant plants.

Journal

Details 詳細情報について

Report a problem

Back to top