Quality of pollen in heterotic combinations of reciprocal hybrids in strawberry (Fragaria vesca l.)

Abstract

The study of the expression of heterosis at the haploid stage (pollen) in the reciprocal interstrain hybrids of strawberry by means of comparison with the pollen of the initial parental forms was done. The following characters were taken into consideration in these comparative studies: the size of the pollen grains, their morphological features, their viability and the durability of the retention of viability estimated by their ability of germination on the agar medium. The forms studied differed from each other considerably (up to 10—20 days) in the duration of viability retention. Difference was found among reciprocal hybrids regarding to this character. Thus, it can be concluded that the characters of gametophyte (haploid) phase depend on the quality of the cytoplasm of the maternal organism.