Molecular Characterization of Wheat Varieties and Assessment of Their Genetic Diversity using Microsatellite Markers

Wheat, a self-pollinating crop, is the most important winter cereal crop grown during the non-monsoon months in the North-Western region of India. There is an increasing demand of improved wheat varieties in order to meet the growing requirements of an ever increasing population. New varieties of wheat are being developed throughout the world for better nutritional as well as commercial value. Genetic diversity and genetic manipulation is an essential tool for rational use of genetic resources and is a prerequisite for any crop improvement program. Assessment of genetic diversity would help in wheat breeding programmes for adaptation to biotic stresses like diseases and abiotic stresses like heat, drought and salt tolerance. The aim of the present study was to molecularly characterize 22 public sector wheat varieties and to assess mutual genetic diversity using 28 microsatellite markers. Ten markers were found to be monomorphic and only eighteen markers showed polymorphism. Eighteen polymorphic microsatellite markers revealed a total of 77 alleles with frequencies ranging from 0.02 to 0.94. The number of alleles per locus varied from 2 to 8 with an overall mean of 4.3 alleles per marker. Mean effective number of alleles per locus was 2.9. Polymorphic information content (PIC value) recorded by the microsatellite markers ranged from 0.12 to 0.80 with mean value of 0.59. Jaccard's similarity coefficient indices were developed on the basis of the scorable banding patterns of the 22 wheat varieties using eighteen polymorphic microsatellite markers. The Jaccard's similarity coefficient values were used as input data to construct a dendrogram based on Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and SAHN clustering using the computer package NTSYSpc version 2.0. The results confirmed the usefulness of microsatellite markers as a tool in the development of suitable DNA fingerprints of wheat varieties and assessment of their genetic diversity at the molecular level.