Variability of inflorescence morphological patterns in Festuca pratensis (Poaceae) populations

摘要

The variability level of two inflorescence morphological characters (panicle length and shape) and genetic diversity value of these patterns in natural and experimental (mutant) populations of meadow fescue are discussed. All populations show different frequency of occurrence of three types of inflorescence shape, pyramidal, diamond-shaped and ovate. Their genetic diversity in this pattern is very high and its level in all populations was practically the same. Population polymorphism of inflorescence length is less pronounced. There was no significant correlation between inflorescence length and shape. Variability values and variation extent of two inflorescence morphological patterns in natural and mutant meadow fescue populations can characterize them as polymorphic ones, and it indoubtedly shows the phenotypic species plasticity. The predominance of one or another inflorescence type is connected with a number of external and internal (genotypical) conditions. Those panicles which deviate from pyramidal shape can be probably considered as inflorescence morphological modifications showing different degree of changes. These changes can appear as a result of a partial reduction of the first axis and branching during th panicle development. These defects can be caused by different reasons-natural (panmixia reduction, affinity breeding, ecological influence) as well as anthropic ones (induced mutagenesis, economic activities, selection).