The spring wheat belt of Western Siberia and Northern Kazakhstan covers more than 15 million ha. While moisture stress is the main factor limiting production, rusts also represent a major challenge, especially in years with higher rainfall. Stem rust was not considered economically important until 2015 when a local epidemic occurred in the Omsk region of Russia and neighboring areas of Kazakhstan and affected more than 1 million ha. It occurred again in 2016 though the spread, severity and losses were less. This study used 16 pathotypes and 17 molecular markers to characterize a set of 146 spring wheat varieties and breeding lines identified as stem rust resistant in Kenya and the Kazakhstan–Siberia region for the presence of major genes. The genetic basis of resistance in the material was limited to Sr25, Sr31, Sr36, Sr6Ai, Sr6Ai#2, and some unknown major genes. Genes Sr25 and Sr6Ai#2 also provided high levels of resistance to leaf rust through linkages with Lr19 and Lr6Ai#2. Adult plant resistance to stem rust was observed in 26 genotypes (16.5 %), including eight possessing Sr57 gene. The high risk of stem rust—as indicated by the 2015 Siberian epidemic—means that there is an urgent need to diversify the genetic bases of resistance and to promote resistant varieties with farmers.
Bibliographical noteFunding Information:
The International Maize and Wheat Improvement Center (CIMMYT) is financially supported by CRP WHEAT. The Kazakhstan–Siberia Network for Spring Wheat Improvement (KASIB) is supported by the Government of Kazakhstan through the Ministry of Agriculture, and by the Government of the Russian Federation through the Eurasian Center of Food Security. Support from the Borlaug Global Rust Initiative (BGRI) was essential for testing germplasm in Kenya. Molecular marker analysis was supported by the Ministry of Education and Science of the Russian Federation (Agreement No. 14.604.21.0106 from 07.07.2014; identification number RFMEFI 60414X0106). Research at Omsk State Agrarian University was supported by Russian Science Foundation (Project No. 16-16-1005 signed 10.05.2016). Dr. Yue Jin from the United States Department of Agriculture Cereal Disease Laboratory (USDA-CDL) is acknowledged for his cooperation in this study and substantial contribution to the manuscript through discussion and editing. Dr. Tamara Kolomiets from the All-Russian Institute of Phytopathology (Moscow Region), Ms. Aygul Akhmetova from CIMMYT-Kazakhstan, and Dr. Igor Belan from the Siberian Agricultural Research Institute (Omsk) are acknowledged for evaluating the germplasm for diseases. Dr. Sergey Martynov from the Vavilov Institute assisted with statistical analysis and Dr. Matthew Rouse from the USDA Cereal Disease Laboratory provided useful information concerning gene postulations. The scientific editorial contribution of Ms. Emma Quilligan is highly appreciated.
© 2016, Springer Science+Business Media Dordrecht.
- Disease resistance
- Stem rust