Genetic Analysis Of Pollination Dynamics In Platycladus Orientalis Seed Orchard

Assessment of pollination dynamics is an important part of the monitoring of mating system in seed orchards,which directly affects the genetic diversity and the quality of seed crops from seed orchards.This thesis aimed to evaluate pollen yield and mating system in a first-generation Platycladus.orientalis seed orchard.To do so,we developed chloroplast(cp)and unclear SSR markers for paternity identification.The main results are as follows:(1)We developed primers for 26 cpSSRs loci which successfully amplified the target in 17 species of 9 genera in Cupressaceae family,providing a good narker resource for genetic research and breeding in Cupressaceae.(2)We detected high level of outcrossing and pollen contamination in the seed orchard.The offspring population has relatively high allelic richness and diversity,but some rare alleles are lost.(3)We found very uneven parental contribution and fecundity among the individuals,and there is no significant correlation between pollen yield and male reproductive success.Based on the results,we recommend active pollen management practices to ensure the genetic diversity in seed crops and maximize genetic gain.Meanwhile,it is necessary to regularly monitor the fecundity of the clones in seed orchards and the mating system in the seed crops to adjust management strategies and extend the service life of seed orchards.This study provides an important reference for genetic improvement and management of P.orientalis and coniferous seed orchard.