Observation of Mitotic and Cytological Effects Induced by Bean Yellow Mosaic Virus in Affecting Leguminous Plants

Bean Yellow Mosaic Virus (BYMV) causing yellow mosaic and leaf malformation was detected and isolated from naturally infected bean plants collected from Southern region of Saudia Arabia BYMV was transmitted mechanically and identified by serologica1 tests. Light microscopy examinations revealed amorphous cytoplasmic and crystalline inclusions in bean plants infected with BYMV. Ultra structural changes in the deformed chloroplasts and grana were severe affected, chloroplasts were more affected, swollen, irregular, rupture lamella, crash grana and combination with each in the form of amoebic. The nucleus was elongated irregular with spindle like shape. The results suggest that the depressive effect in the mitotic process of Vicia faba L. was demonstrated when infected with Bean yellow mosaic virus. Remarkably, there was a progressive decrease in mitotic indices and increase in the total percentage of abnormalities due to bean yellow mosaic virus infection. Types of abnormalities revealed the induction of spindle disturbance, stickiness, laggards, fragments, bridges and micronuclei which lead to the loss of genetic material.