Impact of biased sex ratio on the genetic diversity, structure, and differentiation ofPopulus nigra(European black poplar)

Abstract

Effective population size is a crucial concept of conservation biology. It is reduced by biased sex ratio, consequently causing loss of genetic variation. To evaluate genetic diversity related to gender and investigate possible effects of biased sex ratio, we analyzed available microsatellite DNA marker of 120 Populus nigra samples originated from five geographical regions in Turkey. 
 Using 12 microsatellite markers, we detected 60 clones of the same genotype, out of 120 trees. The clone genotype was observed both in males and females, which might suggest the occurrence of deviation from dioecism. Three genetic clusters were detected, two of which possibly corresponding to commercially available trees. Overall allelic richness was found to be similar for both genders whereas heterozygosity was slightly higher in males. Additionally, a simulation software prototype was developed to see the effects of sex ratio on diversity and allele frequency trends in future generations given the available molecular data. Results showed that if biased sex ratio persists, allele loss and fixation might occur in a higher rate, causing loss of variation.