Certain Cell Level Changes and Chromosomal Aberrations in Tomato Seedlings Induced by Xanthomonas Campestris Pv. Vesicatoria

Abstract

In the tissues of seedlings of two cvs of tomato emerging from Xanthomonas campestris pv. vesicatoria-inoculated seeds, cell level changes and chromosomal abnormalities were found. The cells under such conditions were rectangular, round-cylindrical, thin-elongated, thin-short and cylindrical. Chromosomal aberrations included stickiness at the metaphase stage, formation of lagging chromosomes, accumulation of micronuclei, induction of binucleate condition and non-formation of the cell plate. These abnormalities were more apparent in shoot tip cells than the root tips and were also more frequent in cv ‘Punjab Chhuhara’ than cv ‘Pusa Ruby’.

The changes at the cell and chromosome levels due to the presence of the bacterium ensured cessation of growth and adversely affected eventual differentiation of shoot into stem and leaves. Thus, disturbances at these levels ultimately have bearing on symptom expression, and this aspect should be investigated wherever possible.