Genetic Structure in FCV Tobacco Population as Assessed by Multi-locus Genotyping Using SSR Markers

Ganesh CT, Saiprasad GVS, Moha

Abstract

Association mapping studies largely depend on the genetic nature of the population. An understanding of genetic structure of population assists in designing apt studies that accounts the dynamics of variability in population. Current study is aimed at analyzing genetic structure of tobacco (Nicotiana tabacum L.) population consisted of 135 FCV (Flue Cured Virginia) genotypes using multi-locus genotyping with mapped Simple Sequence Repeat (SSR) markers. 25 unlinked SSR markers delineated 135 genotypes revealing a total of 85 alleles with an average of 3.4 alleles per locus. Contrasting allelic frequencies were observed in most of the loci studied. Bayesian method of inference employed the genotyping data to derive genetic structure information from the population. High FST measures in the subpopulations (0.44, 0.09 and 0.29 at population level K=3) indicated high inbreeding coefficient signifying a strongly structured population. Evolutionary dissimilarity estimate using DARwin also supported the finding of resilient structure in the population. These findings were found highly useful in designing appropriate mapping strategies for tobacco breeding.