Evaluation of Drought Resistance Accession of Wheat (Triticum aestivum) Using ISSR Markers

Abstract

Triticum aestivum is the world’s leading cereal grain where more than one-third of the population of the world uses as a staple food and it is the third most widely produced cereal crop in the world after rice and maize. However, It is very difficult to find areas “without stress,” where Triticum aestivum can reach their maximum yield potential due to abiotic stresses such as drought. Drought is one of the most common external stresses affecting plant growth and development through changes in metabolism and gene expression. Thus it is important to use genetic markers to evaluate drought resistance accessions of wheat. Thus the main objective of this study was to evaluate drought resistance accession of hexaploid wheat (Triticum aestivum) using ISSR markers. Genomic DNA was extracted from 55 selected T. aestivum varieties using DArT plant DNA extraction protocol. The quality and quantity extracted genomic DNAs were measured using spectrophotometry and approximately 1.8 genomic DNA ratio of 260nm/280 absorbance was taken and diluted to 50ng/µl for PCR. PCR reactions for fifty five samples were performed using ten ISSR primers. A total of 73 amplified DNA fragments (locus) ranging from 200-2961bp were produced from 10 ISSR markers. 39 fragments were polymorphic (53.4%) and the rest 34 fragments were monomorphic (46.6%) with the average of 3.9 to 3.4 polymorphisms and monomorphism per primer, respectively. Among ten ISSR primers used for this study, primer 844A, 844B, 17898A, 17898B, 17899A and HB11 have produced specific fragments on expected ranges of primer molecular weight that used to distinguish drought resistance LEA gene in each samples except, primer HB12, HB13 and HB15 those were produced undifferentiated faint fragments. Most of accessions produced specific fragment in each primer, where as some accessions was produced faint bands or no any band formation. This indicated that, most of selected Triticum aestivum accessions were drought resistance. Since, the evaluation of drought resistance accessions has great values for wheat crop improvement through genetic engineering and modern breeding programs, further investigation should be give attention to fragment sequencing, LEA gene isolation and grouping based on amino acid sequences.