In allogamous species meadow fescue the pollination system is accompanied by producing of large amount of pollen possessing ecological plasticity and genetic quality what affects the microgametes value during selection and competition ability of mature pollen. In this connection the state and the level of diversity of microgametophyte fertility were investigated in meadow fescue plants differing in genetic background (mutant populations and plants with suppressed chlorophyll deficiency) and ontogenetic age. 7 mutant populations cultivated for 5 generations and 110 revertant in chlorophyll deficiency clones cultivated for 6 vegetation periods were studied.
It was shown that fertility of the male gametophyte in experimental meadow fescue plants during 5 generations as well as 6 years of life was remarkable for diversity and large varying values. The level of expression and variability of pollen fertility depended on specific genetic (genotypic features of mutant populations and revertants) and nonspecific (number of generations, age) factors. Specific adaptive state in populations was determined by natural selection, particularly by its stabilising form (based on deviation from the mean analysis in the pollen fertility trait). Stabilising selection was mostly favourable to mutant populations formed on the basis of chemical mutagens as compared with gamma-populations and revertants with lighter expression of chlorophyll deficiency phenotype (viridis and xantha) as well.