**Acknowledgements**

We thank Dr. Margarita A. Vishnyakova (N.I. Vavilov All-Russia Research Institute of Plant Industry, St-Petersburg, Russian Federation), Dr. Tatiana S. Naumkina (All-Russia Institute of Legumes and Groat Crops, Orel, Russian Federation) and Dr. Vladimir K. Chebotar ("Bisolbi-Inter" Ltd., St-Petersburg, Russian Federation) for the long-term collaboration in the fields of legume breeding and microbial inocula development. We are also grateful to Victoria Seme‐ nova (Komarov Botanical Institute, St-Petersburg, Russian Federation) for critical reading the manuscript. This work was supported by the grants of RFBR (10-04-00961, 10-04-01146, 12-04-01867), Grant to support leading Russian science school (HIII–337.2012.4) and Govern‐ mental contracts for research with Ministry of Science and Education of Russian Federation (II1304, 16.512.11.2155, #8109).
