Male Fertility Variation and Non-Random Segregation in Pollen Mix Crosses of Picea abies

1994

S. 13-22

19 Lit. Ang.

Unselbständiges Werk

200062783

Grafts of the same clones of Picea abies were pollinated with mixtures of pollen from 2-3 clones at a southern and a northern locality in Sweden (lat. 60Grad and 65Grad). The pollen parents were both of southern and northern Swedish origin. The contributions of offspring from each of the pollen parents in the mixes were determined by isozyme analyses. There were large differences in paternal success between the pollen parents, indicating pollen competition. These effects were in most cases consistent across several maternal parents and between the two localities. They were also verified by measurements of frost damage and height growth in comparisons of pollen mix progenies and their constituent full-sib families. Segregation distortions for paternal gametes were observed in more than 50% of the identified matings from the pollen mixes, but not for maternal gametes. In one mating the distortion was most likely due to selective fertilization pr post-zygotic viability selections. The non-random segregations could be one factor contributing to the differences in paternal reproductive success.