STUDY OF SAMPLES OF VEGETABLE PEA COLLECTION TO RESISTANCE OF ASCOCHYTA IN THE CONDITIONS OF SOUTHERN WOOD STEPPE OF WESTERN SIBERIA

The yield of vegetable peas in the conditions of the Omsk region is largely limited to the defeat of plants by a complex of diseases and damage by phytophages. The aim of the research was to study the collection of pea vegetable samples in Western Siberia and to identify among them the most resistant to Ascochyta. The object of research was 70 samples of vegetable peas from the collections of the Federal Scientific Vegetable Center,  Odintsovo, Federal Research Centre All-Russian institute of plant genetic resources on the name  of  N.I.  Vavilov (VIR), St.  Petersburg,  as  well  as obtained in the framework of cooperation with foreign breeding institutions. The experiments were conducted in the forest-steppe  zone of  the  Omsk region in 2014-2017.  As  a result of the experiments, it was established that the defeat of  peas by  Ascochyta occurs  annually, but  with  different intensity, depending on weather conditions. The maximum resistance of plants was observed in 2016 under conditions of severe drought (5.8 points on average), the minimum – in 2015 with moderately humid and warm weather (3.9 points on average). Late sowing contributes to a greater damage to plants by Ascochyta and reduced productivity. The relationship between resistance to Ascochyta and conditions characterizing heat and moisture supply is strong negative in the initial period of plant growth: with the CGT (r = -0.98 0.13), the amount of precipitation (r = -0.86 0.35), air temperature (r =  -0,67  0,24); strong positive in the second half of the growing season: with SCC (r = 0.82 0.33), amount of precipitation  (r  =  0.68  0.35).  Most  of  the  samples during  the research retained a high (29%) and medium (48%) resistance to  Ascochyta. As a result of  the collection's assessment, samples  of  vegetable peas  resistant  (7-8  points)  to  the pathogen were distinguished: B-1295  (к-8907,  Bashkiria), Chinese (PRC), Terrace 888 (k-9376, Ukraine). These samples  can  be  recommended  as  sources  of  resistance to Ascochyta for the selection of  vegetable peas in Western Siberia.