Investigation of Seed Storage Proteins Diversity in Some Durum Wheat Landraces and Cultivars

Introduction:

Reducing the genetic diversity of crops as a result of the use of breeding processes leads to the loss of a large number of useful genes and thus reduces the diversity of genetic resources, which is one of the undeniable tools of breeding programs. Therefore, researches aimed at studying the genetic diversity of crops can be an effective aid in preserving genetic resources and identifying superior genotypes. Electrophoresis of seed storage proteins is a useful tool to study the characteristics of wheat genotypes in terms of storage proteins diversity. 

Materials and Methods:

In the present study, the diversity of seed storage proteins of 25 durum wheat genotypes obtained from different regions of Iran, including some landraces and commercial cultivars, was investigated using SDS-PAGE electrophoresis. Storage proteins of the studied genotypes were scored and analyzed after extraction and electrophoresis. Grain protein content and total gluten were measured by NIR and glutomatic gluten washer machines, respectively.  

Results and Discussion:

Electrophoresis identified 14 polymorphic bands. Molecular analysis of variance between landraces and commercial cultivars showed 100% intragroup diversity. Cluster analysis using Jaccard coefficients by UPGMA method divided the studied genotypes into 4 groups. Genotypes No. 9 (Land race of Mashhad), 18 (Land race of Ahar) and 24 (Landrace of Islamabad Gharb) were placed each in a separate group and the rest of the genotypes formed another group. The two-dimensional graph resulting from principal component analysis also confirmed these four groups. Based on Jaccard similarity matrix, the lowest similarity and highest genetic distance were determined between genotypes No. 24 (Land race of Islamabad Gharb) with genotypes No. 21 (Dehdasht cultivar), 22 (Land race of Khorramabad), 23 (Dena cultivar) and 25 (Land race of Khorramabad) with a similarity coefficient of 0.41 was obtained. On the other hand, comparing the mean of genotypes for qualitative traits of grain protein content and total gluten, the highest amount of these two traits for genotypes No. 3 (Landrace of Kermanshah), 4 (Landrace of unknown-Iran), 1 (Landrace of Khoram Abad) and 2 (Landrace of Khoramabad) and the lowest values of both traits were obtained for genotype No. 24 (Landrace of Islamabad-West). Genotype No. 18 (Landrace of Ahar) is also one of the genotypes with high amounts of gluten. 

Conclusion:

The electrophoretic pattern of seed storage proteins can determine genetic diversity based on the presence or absence of protein bands. Therefore it can be a useful tool to identify the genetic diversity of different plants. It is also possible for genotypes that have the greatest genetic distance and at the same time have good quantitative and qualitative traits to participate in breeding programs as parents. In the present study, according to the study of genotypes by analyzing the variance of qualitative traits of grain protein content and total gluten and comparing the mean and grouping them using the information obtained by electrophoresis, a cross can be found between genotypes genotypes No. 3 (Landrace of Kermanshah), 4 (Landrace of unknown-Iran), 1 (Landrace of Khoram Abad) and 2 (Landrace of Khoramabad) Due to their high content of gluten and protein with genotype No. 18 (Landrace of Ahar) due to its high content of gluten and acceptable genetic distance with the mentioned genotypes