نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانش‌آموخته کارشناسی ارشد، گروه ژنتیک و بهنژادی گیاهی، پردیس کشاورزی، دانشگاه تربیت مدرس، تهران، ایران
2 استادیار، گروه ژنتیک و بهنژادی گیاهی، پردیس کشاورزی، دانشگاه تربیت مدرس، تهران، ایران
3 استاد، گروه تولید و ژنتیک گیاهی، دانشکده کشاورزی دانشگاه ارومیه، ارومیه، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction
Bread wheat (Triticum aestivum L.) is one of the most important crops in the world, providing more than 40% of the world's food. Increasing wheat production to feed a growing population requires the improvement of genotypes to reduce the harmful effects of environmental stresses and climate changes. To achieve higher yield potential, lower genetic vulnerability, resistance to stresses, and adaptation to climate changes, it is necessary to diversify wheat germplasm resources. For this purpose, it is essential to evaluate the genetic diversity of wheat germplasm and identify superior genotypes for use in breeding programs. Microsatellite (SSR) markers, as the most popular PCR-based molecular markers, have been widely used to analyze genetic diversity in various plant species. The objective of this study was to evaluate the genetic diversity and determine the population structure of a number of bread wheat genotypes using microsatellite markers.
Materials and methods
The plant materials of this study were 70 bread wheat genotypes that were cultivated in a completely randomized design with three replications in the greenhouse of Tarbiat Modares University, Tehran, Iran. Genomic DNA was extracted using the Viragen company kit and the quality and quantity of DNA samples were determined using the nanodrop and agarose gel electrophoresis, respectively. To investigate the diversity among bread wheat genotypes, 30 pairs of wheat Xgwm microsatellite primers were used, and polymorphic information content (PIC) and gene diversity indices were calculated using PowerMarker software. Cluster analysis using the neighbor-joining method was used to determine the population structure and bread wheat genotypes were grouped using TASSEL software.
Research findings
The results of this experiment showed that out of 30 pairs of the studied microsatellite primers, 24 pairs had suitable polymorphism among different bread wheat genotypes. These primers successfully identified a total of 79 alleles, with an average of 3.29 alleles per marker locus. The number of observed alleles at each marker locus varied from two to seven alleles. Xgwm443 marker with seven alleles had the highest number of observed alleles. Polymorphism information content (PIC) with an average of 0.56 varied from 0.14 in Xgwm129 marker to 0.92 in Xgwm174 and Xgwm162 markers. Gene diversity with an average of 0.62 varied from 0.15 in Xgwm129 marker to 0.97 in Xgwm162 marker. Comparison the polymorphism information content and gene diversity showed that these two parameters have a direct relationship with each other. Cluster analysis based on microsatellite markers data using the neighbor-joining method also classified the studied bread wheat genotypes into three different clusters.
Conclusion
Based on the results of this study, Xgwm443 marker with the highest number of alleles and Xgwm174 and Xgwm162 markers with the highest polymorphism information content are introduced as useful and informative markers for evaluating the diversity and differentiation of wheat genotypes and possibly other cereals. In addition to their application in grouping the genotypes, these markers can also be used effectively in identifying genes involved in the control of agromorphological traits. Cluster analysis classified the 70 bread wheat genotypes into three separate groups that did not correspond to the growth type of the genotypes, so that each cluster randomly included a number of genotypes with different growth types.
کلیدواژه‌ها [English]
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