Brown Rust of Rye: Analysis of Long-Term Dynamics and Sustainability Sources

Abstract

The purpose of the work is to assess the prevalence and development of rye brown rust over time, to determine its harmfulness in modern varieties and to identify sources of resistance for further selection. The main counts and studies of crops and the pathogen (Puccinia recondita f. sp. secalis) were carried out in the period 2001-2017 at the central experimental field of “KazSC RAS” (Laishevsky district of the Republic of Tatarstan). As a material for research, 70 collection varieties of winter rye were used, as well as zoned and passed state varietal tests of the variety. An analysis of the long-term dynamics of brown rust in the Republic of Tatarstan showed an increase in the prevalence and degree of development of the disease in the last decade compared to the previous one. Out of 17 years, for five (29.4% of years) the disease assumed the character of epiphytotia, with a prevalence of ≥20%. During the study period, the development of the disease is characterized by an alternation of increase and decrease in the development of the pathogen. As a result of brown rust damage, bushiness of plants decreased to a greater extent (up to 38%), grain weight from an ear (up to 32%) and from a plant (up to 42%). Constant monitoring of the phytosanitary situation and limitation of the harmfulness of brown rust by creating resistant varieties are required. As a result of the research, a gene pool was selected from 11 Russian and foreign winter rye varieties that have high and medium resistance to leaf rust, which are of practical interest for selection.