As part of a multi-year monitoring study of pollination dynamics in a second generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed orchard, we estimated with the aid of eight microsatellite markers three important reproductive biology characteristics affecting the genetic worth and diversity of seed crops; namely parental reproductive success, pollen contamination, and selfing rate. The obtained results were compared to those from two previous years to gauge appropriate seed crop management practices and ultimately allow approximate generalization of seed crop genetic quality. We determined that 80% of parental gametes were produced by 52% of the parents, 13% of paternal gametes resulted from pollen contamination (i.e., gene flow), and 12% of the seed were the product of selfing. The obtained results were in line with those observed for 2005 and 2009 where 80% of gametes being produced by 37–48% of the parents, 10–18% pollen contamination, and 15–17% selfing rate. The observed reproductive biology parameters differences are attributable to the various crop management practices implemented (i.e., bloom delay and supplemental-mass-pollination) across years and calls for justification due to the observed minimal differences on seed crops genetic quality.
Trees from the family Rosaceae play an important role in forest and agricultural ecosystems. Therefore, they are often an object of interest for both forest and horticultural tree breeders. Here, we present the utilization of an effective microsatellite (SSRs) genotyping method for wild cherry (Prunus avium L.) and verified the discriminatory power of the presented multiplex by genotyping 48 genetically distinctive individuals (plus-trees). Concerned loci were previously proven to be cross-compatible among various cultivars of cherry, hence, the method could have a broader utilization beyond to the field of forestry.
Our technique is based on post-PCR processing of 15 polymorphic SSRs loci amplified in three multiplex reactions with fluorescently labeled primers (6-FAM, VIC, PET and NED). All PCR products could be pooled and analyzed simultaneously (pseudo 15-plex). In order to make this approach feasible, we redefined sequences of several primers. Thus, utilizing modified primers provides non-overlapping amplicons of each fluorescent dye.