[DIALLEL ANALYSIS OF STOMATAL TRAITS IN TRITICUM AESTIVUM L].

The guard cell size and stomatal density are important interdependent traits (r = -0.67 ± 0.146) of plant adaptive response to environmental stresses. The purpose of this study was to determine the types of inheritance, the number and effects of genes controlling phenotype of the above-mentioned leaf stomata characteristics. Hybrid F1 values, resulting from crossing by 7 x 7 half diallel crosses and values, and parental midpoints were used. Genetic control of the trait "length of guard cells" is based on the complete domination of the larger length. In the inheritance of "stomata density" the additive components were significant. It was established that recessive alleles are responsible for the increasing of stomata density (r = 0.93 ± 0.07) and their number was highest in Cultivar Odesskaya 16.

The effects of task constraints on the organization of interception movements.

In the light of the intensity coupling effects reported in the literature, subjects' capacities for independently controlling the absolute velocity of their movement at the point of interception was evaluated by asking them to learn to propel orthogonally approaching balls, varying in their speed of approach, into target boxes placed at various distances from the interception point. As required for successful accomplishment of the task, movement velocity was found to be adapted to the distance to be covered, with the near target giving rise to lower velocities and the far target giving rise to higher velocities even when the conditions were presented in random order. Nevertheless, even though target distance accounted for a substantial proportion of the total variance, a small but significant effect of ball approach speed on movement velocity was found, suggesting that intensity coupling is a persistent but modulable phenomenon in interception tasks.