Marker-Assisted Breeding of Recombinant 1RS.1BL Chromosome for Improvement of Bread Making Quality and Yield of Wheat (Triticum aestivum L.)

Abstract

The 1RS.1BL translocation has been extensively used as a source of genes on 1RS for multiple disease resistance (Lr26, Yr9, Sr31 and Pm8) and enhanced yield of wheat cultivars. However, cultivars with the 1RS.1BL translocation have sticky dough due to the presence of Sec-1 on 1RS and absence of Glu-B3/Gli-B1 on 1BS. Many QTL useful for root traits have also been mapped on 1RS. A tertiary recombinant 1RS line lacking Sec-1 but with useful root QTL and Glu-B3/Gli-B1 of 1BS has been developed at the University of California, Riverside USA which is being used for marker-assisted breeding of wheat cultivars for higher yield and improved bread making quality. PCR-based SSR markers (ω-sec-P3/P4, Rye R3/F3, Psp3000, Sfr 43) were used to check the presence of Sec-1, rye translocation, Glu-B3/Gli-B1 and Pm8 for characterization of wheat cultivars and 1RS recombinants, respectively. The markers amplified the desired amplicons and were well synchronized to each other about the presence and absence of various genes in each cultivar and recombinants. The absence of Pm8 and poor root traits in MA1Pavon confirmed the close association between Pm8 and useful root QTL. Two of the recombinants, i.e., 1B+38 and 1RS44:38 were found to have Pm8 gene as well as better root traits than in MA1Pavon. The SDS micro-sedimentation test of various 1RS recombinants and parental lines showed that 1RS–1BL with Sec-1 had lowest micro-sedimentation test (MST) value while addition of Glu-B3/Gli-B1 had negligible improvement. These findings suggest that the MST values are not much affected by the absence of Glu-B3/Gli-B1 and hence the lines having better root traits with no Glu-B3/Gli-B1 and secalin could be used for improvement of bread making quality and yield in wheat.