Resistance of sugar beet genotypes to salt stress

In this work, using biochemical and molecular genetic approaches, the genotypes of sugar beet were studied under conditions simulating salt stress in order to select stable samples for breeding. Sugar beet plants grown under conditions of 150 mM, 280 mM and 500 mM salinity were used as materials for experiments. Under conditions of 150 mM salinity, samples RMS-127, O-type 2113, OP 021729, MS 020026 showed an increase in catalase activity by 33.0 %, 14.1 %, 81.4 %, 5.1 %, accordingly, with respect to control samples. In these genotypes, with an increase in NaCl concentration to 280 mM, an increase in superoxide dismutase activity was noted, in RMS-127 by 28.9 %, MS 020022 – 78.7 %, O-type 09001 – 54.3 %, OP 021722 – 65.5 %, OP 021729 – 67.3 % relative to the control. As a result of quantitative real-time RT-PCR, the expression of the SOD and CAT genes was detected in the studied sugar beet genotypes under conditions of 150 mM and 280 mM salinity. An increase in the expression of the SOD gene was shown in samples MS 020026, O-type 2113 and OP 021729 at 150 mM salinity, on average 2.5 times relative to the control. The maximum expression level of the SOD gene was established in the genotypes MS 020022 and RMS-127 at 280 mM salinity (1.5 times higher than the control). In MS 020026, MS 020022, O-type 09001, the maximum values of gene expression were recorded at 150 mM and 280 mM of salt, more than 5 times, and 3 times in O-type 2113 at 150 mM of salt, compared with the control. According to the results of the study, all the studied genotypes were selected as salinization-resistant starting material for breeding.