RESISTANCE OF BARLEY VARIETIES TO THE PATHOGENS OF LEAF SPOTTING ON THE ARTIFICIAL INFECTIOUS BACKGROUND
Leaf spotting is one of the most common and harmful diseases of white straw crops in Northern Kazakhstan and is caused by some fungi as Drechslera graminea, Cochliobolus sativus Pine., Bipolaris sorokiniana, Alternaria fungi species: Alternaria arborescens, Alternaria tenuissima, Alternaria alternate, Alternaria triticina. The symptoms of leaf spotting vary, depending on the genotype of the host plant, the phase of plant development, and environmental conditions. The fungus infects through direct penetration into the epidermis of young leaves or through the stomata, forming clearly limited, dark brown spots. The first signs of the disease appear on the seedlings in spring, in the form of oval brown spots. Spots can develop on leaves and leaf sheaths at all stages of plant development.The majority of barley varieties, cultivated in the conditions of Northern Kazakhstan, have a comparative resistance to fungal diseases in terms of resistance to leaf spotting. As a result of studying the nature of stability of barley varieties, Solontsoviy variety was characterized by low plant damage during ontogeny. Such varieties as Donetsk 9, Astana 2007, Karaganda 5, Medicum 307, Tselinniy 30 and Tselinniy 93 are moderately resistant.