THE ESTIMATION OF CORN INBRED LINES BY COLD RESISTANCE AND SSR MARKERS

Purpose. Classification of the source material of maize by the rate of cold resistance, identification of self-pollinated maize lines in laboratory and field conditions by cold resistance and main economically valuable indicators, and their genotyping based on SSR markers.

Methods. Field and laboratory methods, molecular genetic analysis.

Results. As a result of studies based on the cold test, the ranking of self-pollinated lines of corn on 6 groups was carried out in accordance with the level of their cold resistance. It was revealed that the type of grain does not affect the ranging result, since lines with different types grain belong to the most cold-resistant ones. It was determined that field germination of maize lines varied depending on the sowing period and amounted to 32,1–87,8% at the first (6–6,5 °С), 41,8–88,5% at the second (8–8,5 °С) and 51.1–90.0% at the third (10–10,5 °С) sowing dates. It was determined that self-pollinated lines: HLG 1203, HLG 1238, Co 255, UCH 37 and FV 243, Q170, AK 135, F2, L155 and P165 have the best regenerative ability and high germination under conditions of cold germination of seeds and its maintaining relatively to control. Based on the results of field studies, the lines Co 255, HLG 1203, HLG 1238, and Q 170 were identified, in which the germination rate (in percent) was high compared to the control. Based on the assessment of the yield of self-pollinated maize lines, it was determined that they react differently to the sowing dates. As a result of PCR analysis of 13 cold-resistant lines, genetic polymorphism was determined by 5 SSR markers. According to obtained results, the presence of 3 to 7 alleles was revealed. PIC was 0.56–0.86. It was determined that, using the three markers bnlg1129, bnlg1782 and phi064, intralinear polymorphism was detected in the studied lines. The results of the studies allowed to obtain four clusters which reflect the degree of genetic proximity to the studied markers. It was found that lines the Ak 135 and Ak 153 entered the same cluster are the most related and the most distant lines are Co225 and Q 170. The obtained data indicate that the studied maize lines formed clusters according to their origin and some lines according to their cold resistance.

Conclusions. According to the results of studies, 7 self-pollinated lines of corn (Co 255, HLG 1203, HLG 1238, Q 170, UCH 37, Ak 135, FV 243) were indentify. They are valuable sources for breeding to cold resistance.