Markers for the Y Chromosome of Silene latifolia and Their Use in Studying Pollen Tube Growth Rates

Abstract

InSilene latifolia. females (XX) and males (XY) naturally differ from each other in many genes other than those located on the sex chromosomes. We masked differences which were not sex linked by pooling 18 females into one sample and 18 males into another (For the method, see Michelmore, et al. submitted). Differences between the two samples would presumably relate to the Y chromosome. DNA was extracted from the two samples and subjected to polymerase chain reaction amplification with 10 bp arbitrary primers (see Williams, et al. 1990). Any amplification from the bulked male DNA not found among those from the bulked female DNA was likely to include a Y chromosome sequence. Four putative Y chromosome markers were obtained and each was subsequently detected in all individual males tested. Y chromosome markers were not found in any of the individual females tested. These results suggest that we have reliable markers for the Y chromosome in our population ofSilene latifolia. These markers, as is explained belwo, will facilitate future studies of pollen tube competition.