Phosphoglucose isomerase polymorphism in cultivated groundnut (Arachis hypogaea L.) and some of its wild relatives in section Arachis

Abstract

Horizontal starch gel electrophoresis was used to study one of the enzymes involved in glycolysis, Phosphoglucose isomerase subunits (PGI) (EC 5.3.1.9), in the cultivated groundnut, Arachis hypogaea, and some of its wild relatives. Two gene loci specifying PGI were detected. The more anodal locus, Pgi-1, was monomorphic in all the species studied. Polymorphism was detected at the locus close to the origin, Pgi-2, in the cultivated ground-nut as well as the wild species, with two distinct alleles present at this locus. The two subspecies of A. hypogaea exhibited different banding patterns. With few exceptions, ssp. hypogaea accessions exhibited homozygosity for the first allele while all accessions of ssp. fastigiata exhibited 'fixed' heterozygosity for the two alleles at the second locus. These differences serve as significant markers for sorting landraces of the cultivated groundnut into subspecies and appear to correlate well with the established morphological differences in the subspecies of A. hypogaea already known to groundnut workers. The probable significance of heterozygosity in cultivar performance is discussed.


Journal of Applied Science and Technology (JAST) , Vol. 5, Nos. 1 & 2, 2000, pp. 129-141