abstract
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The replacement of the short arm of wheat chromosome 1B with short arm of rye 1R chromosome (1BL/1RS translocation) has been widely used around the world due to its positive effects towards yield potential, resistance to rust and mildew and wide adaptation. However, the translocation is combined with inherent quality problems associated with reduced dough strength and dough stickiness (`sticky dough syndrome') as compared to lines having 1BL/1BS. This is due to loss of ω-gliadins, γ-gliadins and LMW subunits of glutenin encoded by loci on 1BS with ω- and γ-secalins encoded by Sec-1 locus on 1RS translocation. Present work was aimed at improving dough quality of two important Indian wheat varieties PBW550 and DBW17 with 1RS translocation by replacing two important loci on 1RS with their counterparts from 1BS. Two loci were transferred from two already developed NILs, one carrying the wheat locus at distal end of 1RS (1RSRW) and the other carrying wheat locus at its proximal end (1RSWR) with maker assisted backcross breeding (MABB). These newly developed lines in both the backgrounds were characterized based on the biochemical (Free amino acid content, Total protein content, Total carotenoid content, Total phenols) as well as quality traits (Hectolitre weight, Grain hardness score, SDS-sedimentation value, Phenol reaction score, Grain appearance score, Gluten content and Gluten index) for two years. The combined analysis of genotypic variance and genotype x environment was significant at 5% level of significance for all the traits other than protein content. The 126 best performing lines were evaluated for bread making characteristics of water absorption, dough consistency, bread weight, specific volume, crumb texture and overall acceptability. A total of 13 lines (9 of Glu-B3-/Sec-1- and 4 of Glu-B3+/Sec-1+) were selected for bread making based on the superior performance than the respective recurrent parent for all the biochemical and quality characteristics specifically for the main quality traits as of SDS-sedimentation value, dry gluten content, gluten index and protein content. The dough stickiness of these lines was reduced in both the backgrounds. Out of 9 lines of Glu-B3-/Sec-1, 5 lines performance was superior and from Glu-B3+/Sec-1+ lines, 2 performed quite well as compared to recurrent parents. We were able to develop bread with higher loaf volume with more the airy texture because of the retained glutenins and gliadins.