Histopathological studies of powdery mildew of chilli.

摘要

The histological study of powdery mildew (Leveillula taurica)-infected and healthy leaves of chilli (Capsicum annuum) revealed that the microtome sections of healthy leaves showed thick and intact epidermal layer with cylindrical palisade and parenchyma cells. In diseased leaf microtome sections, the upper and lower epidermis were disintegrated but not intact. The cells were irregularly distributed, and disintegration of stomata and damaged cuticle were also observed. Histochemical studies revealed that the concentration of polysaccharides, proteins and nucleic acids differed between healthy and diseased leaf tissues. Healthy tissues exhibited medium to rich concentration of polysaccharides, total proteins and nucleic acids, while a reduction of insoluble polysaccharides, total proteins and nucleic acids in diseased leaf tissues was observed. The pathogen depleted the host leaf tissues of these important metabolites due to fast degradation, i. e. varied metabolism.