SOURCES OF BARLEY RESISTANCE TO HELMINTHOSPORIOTIC DISEASES AND THEIR USE IN THE NORTH-EAST FARC

The paper explores 70 samples of spring barley from the collection of WIR under conditions of rather rigid natural infectious helminthosporioses (striped, reticulated and dark brown spotting) in FARC of the North-East in 2018-2019. The spotting was investigated 4-5 times during plants ontogenesis every 10-12 days since the phase 29 on the Cadox scale. The methodology suggested by O.S. Afanasenko (2005) was used to assess the diseases. The nature of vegetative-microbial interactions was evaluated by SCDP (square under the curve of disease progress) and IS (stability index) indicators. During immunological experiment, the authors observed 11 samples resistant to dark brown spotting with lesion rate 10.0-13.0%, SCDP parameters equal 167-223, DUT was 0.18-0.25; 18 samples resistant to reticular spotting (6.0-10.0%, PCRB - 53-103, DUT - 0.18-0.35), and 29 samples characterized by immunity and high resistance to stripe spotting (0-5.0%, SCDP - 10-75). IS - 0.01-0.09). Only 4 samples (Makbo, Kalkul, Buyan and Forward) are characterized by group non-specific resistance to reticulate and dark brown spotting and striate immunity. The longest occurrence period (2-7 days) of dark brown spotting was observed in 8 samples, and reticulum spotting (2-13 days) - in 16 samples. The paper finds out that NCL 95098 (Argentina) had the relatively long occurrence period in terms of dark brown spotting, and varieties from Afghanistan (k-5983) and China (k-2929) to reticulate spotting. Badiory, Makbo, Rodos, and Buyan varieties have equal dynamics of both spotting and slow rusting of diseases in ontogenesis. There is a weak (r = -0.33 - reticulate) and medium (r = -0.58 - dark brown) negative correlation between the latent period and the defeat. The regression equations (y = -0,6071x+6,8571; R2 = 0,917 - dark brown; y = -0,3941x+11,35; R2 = 0,733 - reticulated) show that from infection to the first disease symptoms, their daily increase in trend is 0,61 and 0,39%. Kalkul, NCL 95098, Badioryi and Buyan varieties are seen as effective promising for selection programs to produce high yield adaptive varieties under the conditions of the region. Apart from stability, they are distinguished by the number of productive stems, long, well-grained ears and high productivity.