Grain yield and yield components of spring barley genotypes as the indicators of their tolerance to temporal drought stress

Abstrakt

In 2011, a research project on breeding spring barley genotypes tolerant to temporary drought stresses was started. The authors’ responsibility was to test the productivity of genotypes derived from different parental forms obtained as part of the project on drought resistance studied in a pot experiment. In the years 2011–2013, three consecutive series of experiments with approximately seventy genotypes each year were carried on. Two reference Polish varieties were included in each set. In the control treatment, plants were grown at the optimal soil moisture level of 13–15% weight by weight for the whole growing period. Drought stresses were introduced at the tillering stage (BBCH 23) for the period of 11 days or at full flag leaf stage (BBCH 45-47) for the period of 14 days. At both stress treatments, the moisture was maintained at the level of 5–6% weight by weight. Plants were harvested at full maturity stage. The grain and straw yields, yield components i.e. number of productive tillers, number of grains per spike and weight of 1000 grains were determined. Spring barley showed a higher tolerance to the drought stress at tiller- ing stage than it did at flag leaf stage. Barley genotypes differed in their response to temporary drought stresses due to diverse ability for regenerating after the stress removal. The tolerance of the spring barley genotypes to drought stress imposed at tiller- ing stage resulted from their ability to produce additional fertile tillers. The tolerance of the spring barley genotypes to temporal drought stress at flag leaf stage can be explained by compensa- tion of the reduced grain number per spike through increasing the weight of 1000 grains.