Development and Characterization of SSR Markers in Proso Millet Based on Switchgrass Genomics
Proso millet (Panicummiliaceum)
has highwater use efficiency (WUE), a short growing-season, and is highly
adapted to a semi-arid climate. Genomic resources for proso millet are very limited. Large
numbers of DNA markers and other genomic tools in proso millet can readily be
developed by using genomic resources in related grasses. The objectives of the
present report were to 1) test and characterize switchgrass
SSR markers for use in proso millet, and 2) elucidate repeat-motifs in proso
millet based on new SSR marker analysis.
A total of 548 SSR markers were tested on 8 proso millet genotypes. Out of these,
339 amplified SSR markers in proso millet. This showed that 62% of the
switchgrass SSR markers were transferable to proso millet. Of these 339 markers, 254 were highly polymorphic among the
8 proso genotypes. The resolving power of these 254 polymorphic SSR markers ranged from 0.25-14.75 with an average of 2.71. The 254
polymorphic SSR markers amplified 984 alleles in the ranges of 50 bp to 1300 bp. The majority of the SSR markers (221 of
254) amplified dinucleotide repeats. Based on SSR marker analysis, AG/GA was
the most abundant repeat-motifs in proso millet. Switchgrass genomic
information seems to be the most useful for developing DNA markers in proso
millet. Markers developed in this study will be helpful for linkage map
construction, mapping agronomic traits and future molecular breeding efforts in
proso millet.