Anatomical structure of leaf sectors with different resistance to powdery mildew (Erisiphe cruciferarum Opiz ex. L. Junell) in winter rapeseed chimera

Abstract

The subject of the study was a sectorial chimera of dihaploid winter rapeseed, obtained with the help of gamma ray treatment (30 Gy) during shoot cloning in vitro. One sector of the plant was infected by <i>Erisiphe cruciferarum</i> Opiz ex. L. Junell and the other one was resistant. The anatomical structure of a leaf, divided into the two sectors along the midrib, was studied. The infected part of the leaf blade was thinner and built of a smaller number of palisade and spongy mesophyll cell layers. The size of cells in this sector, both in the epidermis and in the mesophyll, as well as the size of nuclei, chloroplasts and intercellular spaces were bigger than those in the resistant portion. On the other hand, the stomata in the infected segment were smaller but their number was higher than that in the healthy part. The study made it possible to analyse the relation between the anatomical structure of the host plant and the pathogen.