Genetic Diversity

Chenopodium IGS/Ancestry:

Quinoa is a tetraploid (4x) derived from ancient hybridization between two unknown diploids. Thus, we would expect that there are at least two copies of every genetic locus. However, one of the 18S-5.8S-25S ribosomal RNA (aka NOR rDNA) loci has been deleted in quinoa. We are comparing the sequence of the variable portion of this locus, the intergenic spacer (IGS), among candidate-ancestor 2x wild diploids with 4x quinoa and 4x Mexican huauzontle (C. berlandieri nuttaliae) in an effort to identify the ancestors of these crop species and to study the evolution of this important genetic locus.

Chenopodium Ancestry 5S rDNA:

In contrast to the NOR rDNA loci, 4x quinoa has retained two separate 5S rRNA gene loci. We are studying the variable non-transcribed spacer, or NTS, of these genes and comparing the sequences to those of 2x potential ancestors and 4x Mexican huauzontle (C. berlandieri nuttaliae) to shed light on phylogenetic relationships among these species.