Analysis of genetic variation using ISSR and the development of SCAR marker in synthetic autotetraploids of Vigna mungo (L.) Hepper

Abstract

Autopolyploidy is one of the foremost mechanisms by which additional numbers of genome copies are acquired resulting in genetic and evolutionary novelty to the organisms. As such, it is considered to be a pathway for adaptation and has played a significant role in plant speciation. Autopolyploids are characterized by increased genome flexibility, allowing them to adapt and persist across heterogeneous landscapes in the long run. Genomic redundancy and polysomic inheritance are the hallmarks of doubled genome(s). In view of the significance of autopolyploidy in plant evolution, plant breeding and crop improvement, we sought to investigate the genetic variation/s associated with genome multiplication by exploiting artificial somatic autopolyploids in Vigna mungo. ISSR was employed to detect and identify any genomic DNA variation in colchitetraploids of V. mungo of three different generations, viz. C0, C1 and C2, in comparison to their putative diploids plants. Our data suggests a random, ‘short-term’ rapid change of the genome that may have occurred immediately after polyploidization. The population of autopolyploids demonstrated some degree of genetic heterozygosity in comparison to their diploid counterparts. Further, a polymorphic ISSR DNA loci was identified among the colchitetraploids which was translated into SCAR marker for identification of colchitetraploids versus the putative diploids of V. mungo.