Document Type : original paper
Authors
1
Ph. D. Student of Plant Breeding and Biotechnology, Faculty of Crop Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan
2
Associate Prof., Dept. of Plant Breeding and Biotechnology, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
3
Assistant Prof., Dept. of agronomy and plant breeding, Faculty of Agriculture, Shahed University, Tehran, Iran.
4
Assistant Prof., Dept. of Plant Breeding and Biotechnology, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Abstract
Introduction and purpose: The quantitative traits are severely influenced by environmental factors, the most important result of which is that the relationship between genotype and phenotype remains hidden, incompletely or completely. Therefore, it is very important for the breeder to know the effect of the environment on quantitative traits. One of the important quality characteristics in wheat breeding is the quality of stored proteins. Glutenins with low molecular weight have an effect on the formation of large glutenin polymers and the elasticity of the dough, and all products made from bread wheat require a dough with large elasticity. The goals of the present research are to investigate the interaction effect of genotype x environment using univariate methods in advanced backcrossing lines of bread wheat, to identify and introduce lines with high and stable economic performance and improved cultivars containing desirable alleles of glutenin with low molecular weight.
Materials and methods: In current research, the stability of grain yield of five advanced backcross lines of bread wheat (BC2F6) along with their parents in the form of a randomized complete block design with three replications in three locations of Tehran, Kermanshah and Gorgan and cultivation years (2017-2018) and (2018- 2019) were investigated. Each line was planted in plots with eight rows of four meters length with 25 cm distance. DNA extraction was done according to Doyle and Doyle (1987) method. The quality and quantity of extracted genomic DNA were evaluated using 0.8% agarose gel electrophoresis. PCR reaction for amplification of marker fragments was performed using four pairs of allele-specific primers of low molecular weight glutenin encoding genes in a volume of 15 microliters. Separation of amplified marker fragments were done using 2% agarose gel electrophoresis.
Findings: The results of composite variance analysis showed a highly significant difference at one percent probability level for the effect of environment and interaction effect of genotype × environment. No significant difference was observed between the studied genotypes for grain yield. Based on the results obtained from Rick, Eberhut and Russell's equivalence and the coefficient of phenotypic changes of genotype L4, based on the results of Finley and Wilkinson's method and the stability variance of Shokla genotype L3 and L4 and based on methods of Plaisted and Peterson and Plaisted genotype 4 as stable line with high performance compared to the other tested genotypes. In the investigation of the allelic diversity of glutenin subunits with low molecular weight, the results showed that the size of the replication bands between the recurrent parent of Typhoon and the five lines resulting from backcrossing (L1, L2, L3, L4 and L5) in four primers were investigated.
Conclusions: In the general summary of the methods used, the L4 genotype is introduced as a stable line with high performance, and to obtain the maximum performance, it is suggested to cultivate this line in the investigated environments. Four gene loci controlling glutenin with low molecular weight investigated as an effective factor in bakery value have been transferred from the periodic parent Typhoon, which is a cultivar with high bakery quality, to the progeny resulting from backcrossing, so the progeny have high bakery quality.
Keywords: stability, allelic diversity, low molecular weight glutenin subunits, wheat
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