Abstract:

The results of the study of drought tolerance of isogenic (NILs – near isogenic lines) by genes PPD (photoperiod) wheat lines and isogenic by genes ЕЕ (early maturation) soybean lines, that control the photoperiodic sensitivity are presented. In field experiments the photoperiodic sensitivity of the lines when grown under natural long days (16 hours at a latitude of Kharkov) and under artificial short-day (9 hours) is determined. The results showed that line PРD-D1A and PPD-A1a wheat and soybean lines L 71-920 had a weak photoperiodic sensitivity (weak PPDS) and line PPD-B1a wheat and soybean lines L 71-920 - strong photoperiodic sensitivity (strong PPDS). Wheat and soybean lines with weak PPDS were more productive. When simulating drought action on seed germination (20% strength mannitol solution - rapid method), it was showed that the seeds of soybean and wheat lines with weak PPDS have a higher germination than seeds of the lines with strong PPDS. When simulating soil drought (30% FMC – field moisture capacity of the soil) under growing experiment, it was revealed that the biomass accumulation indices of plants, leaf relative water content (RWC) and proline content in leaves lines with weak PPDS were higher than in the photoperiodic lines with strong PPDS. So, all used methods for determining drought tolerance showed that the low photoperiodic sensitivity lines are more resistant to drought. It is assumed that wheat genes PPD and soybean genes EE can participate in the formation of resistance to drought. Genotypes with low photoperiodic sensitivity should be used in breeding soybean and wheat drought resistance.

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