Identification of barley cultivars using SDS-PAGE electrophoresis

Janne Roininen,Matti Puolimatka,Seppo Pulli,Eero Nissilä

doi:10.23986/afsci.72430

Abstract

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was applied to cultivar identification. Three different extractions methods were used to extract and fractionate the seed storage protein subunits from crushed single seeds of barley (Hordeum vulgare L.). Fifty-four genotypes including breeding lines and released cultivars were analysed and grouped according to the variation found in their protein banding patterns. In the first extraction, eight genotypes showed unique hordein subunit composition whilst remainder fell into 11 groups of 2 to 8. The other two extractions were carried out to characterize those genotypes producing identical banding patterns when using the first method. Relative mobility (REM) values for hordein bands were determined. Genetic background was found to strongly effect the determination of hordein composition of barley genotypes. Those genotypes with largely common ancestry showed often similar hordein composition and were difficult to identify whereas genotypes possessing unique hordein banding patterns had clearly exceptional pedigree. The effect of the row-type on hordein banding pattern was not clear as both two-row and many-row barleys were found to produce identical patterns. Intra-cultivar hordein polymorfism was found in three cultivars.

Highlights

The correct identification of barley cultivars is important to plant breeders for protection of their proprietary rights on cultivars and to crop users for the determination of grain suitability for different end-uses, especially malting
Clear and reproducible hordein banding patterns in B, C and D hordein groups were obtained with all three extraction methods used in the study
The absence or the presence of a protein band can be seen as a sufficient indicator of genetic variation, whereas the intensity of the protein bands can vary according to the protein content being quantitative in nature

Summary

Introduction

The correct identification of barley cultivars is important to plant breeders for protection of their proprietary rights on cultivars and to crop users for the determination of grain suitability for different end-uses, especially malting. Several approaches have been introduced to enable characterization of genotypes from single or half seeds as a complement to the identification method of visual examination of heritable morphological differencies of whole plants or grains These techniques, including electrophoresis, isoelectric focusing and chromatography, have been used to obtain qualitative information about the variation in hordein, the alcohol-soluble seed storage protein, dependent upon the genotype and independent on the growth environment. In contrast the B and C groups, the major hordeins rangeing in molecular weights from 32 000 to 45 000 and from 45 000 to 80 000 respectively, show a wide variation in protein composition and are encoded by two separate but linked multigenic loci Hor and Horl located on the short arm of chromosome 5 (Jensen et al 1980, Shewry and Miflin 1982, Heisel et al 1986, Entwistle 1988). D hordeins, minor components with higher molecular weight, are encoded by locus Hor locating on the long arm of the same chromosome and exhibiting a limited but recognisable polymorphism (Shewry et al 1982, 1983)

Methods

Results

Conclusion