Cereals are known to be recalcitrant to the induction of morphogenesis in vitro and the majority of the methods used are callus-mediated and species/genotype-dependent. In the present investigation, a method of morphogenesis induction from immature scutella of selected barley cultivars was used, and particular attention was paid to histology in the initial stages of the regeneration process in order to confirm whether it occurs directly or indirectly (via callus formation). The length of the period from inoculating scutella on the medium to obtaining plantlets depended on the cultivar and the individual scutellum of the barley and varied between 2.5–4 months. The regeneration efficiency and viability of barley scutella was revealed to be highly genotype dependent. The average number of regenerated plants per regenerating scutellum was highest in the case of cv Granal (3.7). A histological analysis of the cultured explants showed both non-morphogenic and morphogenic callus formation. Two types of indirect morphogenetic response were observed: organogenesis (shoot bud formation) and somatic embryogenesis. This is the first report concerning an analysis of in vitro regeneration from immature scutella of barley cultivars (Stratus, Ryton, Granal and Binal).

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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 Erisiphe cruciferarum 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