NUCLEOTIDE POLYMORPHISM IN THE ADH1 LOCUS OF PEARL-MILLET (PENNISETUM-GLAUCUM) (POACEAE)

We investigated nucleotide polymorphism in the Adh1 locus of pearl mil let (Pennisetum glaucum) (Poaceae) by determining the DNA sequence of 20 alleles from 10 individuals. The individuals were sampled from thro ughout pearl millet's indigenous range and represent both wild and cul tivated accessions. Our results indicated that there is little nucleot ide polymorphism in the Adh1 locus. Estimates of per site nucleotide p olymorphism did not differ significantly between cultivated and wild m illet accessions. We compared nucleotide polymorphism in pearl millet Adh1 with nucleotide polymorphism in maize (Zea mays) Adh1 and conclud e that the maize Adh1 sample is more polymorphic. Increased polymorphi sm in maize Adh1 may be attributable, in part, to faster substitution rates in the maize lineage. Analysis suggests that substitution rates in the maize Adh1 lineage are similar to 1.7 times faster than substit ution rates in the miller Adh1 lineage.