A near-isogenic line (NIL) of the Indian wheat variety HD2733, carrying an introgressed Lr24/Sr24 genomic region was used for studying the effect of this introgression on quality traits. Data on the grain yield and 21 quality traits were recorded in this NIL and its recurrent parent (RP), both of which were grown in a randomized block design for two consecutive years. The statistical analysis revealed that grain yield was on par between the NIL and the RP. The NIL and its RP were both hard grained but the NIL showed a grain hardness index reduced by 9.7%. However, quality traits such as grain weight, protein content, sedimentation value, gluten traits, and solvent retention capacity were significantly higher in the NIL. The NIL also showed an increase in dough stability, a lower degree of softening and a higher farinograph quality number. These results indicated that the NIL could be utilized for hard grain, high protein and strong gluten-based products. An overall improvement in the quality of the NIL over its recurrent parent and without any yield penalty suggests that the Lr24/Sr24 genomic region could be gainfully utilized in wheat breeding for improving the industrial quality of wheat without jeopardising grain yield. The authors suggest that the improved quality of the NIL may be due to the genomic segment carried along with the Lr24/Sr24 genes.

The genes for grain softness and rust resistance were transferred from a soft grained Australian wheat variety (Barham) to a hard grained Indian wheat variety (DBW14) through marker assisted back cross breeding. Backcrosses were made with recurrent parent in the BC1F1 plants that were found positive for markers of Pina-D1a, Pina-D1b and Lr37b genes. The BC2F1 plants were further screened and those that possessed the PinaD1a and Lr37b alleles were advanced up to BC2F4 with continued marker assisted selection and field screening. 48 SSR markers that were heterozygous in the BC1F1 plants were used for background selection in three BC2F1 plants derived from three respective BC1F1s. Further generations were screened for morphological traits in the field and 16 BC2F4 lines were finally selected through combined field and marker screening. These 16 near isogenic lines (NILs) had lower grain hardness index (13.86–47.13) than the recurrent parent DBW 14 (81.76) and displayed more than 95% of the recurrent parent genome. 12 of the NILs had significantly higher grain yield than DBW 14. Combined foreground and background selection strategy coupled with field screening, was thus, found to be an effective strategy for transferring grain softness in wheat.

To study possible effects of the three near isogenic lines (NILs) carrying genes, Sr26, Lr19 and Yr10, a collection of BC2F6 lines containing each of the genes singly were grown in a randomized complete block design with two replications (plot size 7.2 m(2)) for two successive years in the same location. Data were collected on grain yield and 20 flour quality traits and were statistically compared (SPSS version) to understand the effect of the transferred segment on these traits, if any. Thousand kernel weight of the lines carrying Sr26 and Yr10 was reduced significantly while that for the line carrying Lr19 increased significantly. Sr26 NIL had grain yield decrease by 12.5% while the other two were on par with the recurrent parent (RP). Protein content, gluten index, sedimentation value, solvent retention capacities were also decreased significantly in Sr26 NIL Dough development time and dough stability of the three NILs increased significantly but it was the highest for the line carrying Lr19. Sr26 NIL, showed a drop in farinograph quality number due to higher degree of softening as compared to RP. Lr19 NIL did not differ in flour colour from RP and no yellowness of flour was observed. Generally Lr19 and Yr10 carrying lines are without any detrimental effects on yield and quality. Sr26 appears to be carrying linkage drag as it showed an adverse effect on yield and quality. Screening thousands of backcrossed plants with molecular markers in the vicinity of Sr26 may help recover some with RP genome and overcome the adverse effects associated with this introgression.

Grain softness has been a major trait of interest in wheat because of its role in producing flour suitable for making high-quality biscuits, cookies, cakes and some other products. In the present study, marker-assisted backcross breeding scheme was deployed to develop advanced wheat lines with soft grains. The Australian soft-grained variety Barham was used as the donor parent to transfer the puroindoline grain softness gene Pina-D1a to the Indian variety, DBW14, which is hard grained and has PinaD1bPinbD1a genes. Foreground selection with allele-specific PCR-based primer for Pina-D1a (positive selection) was used to identify heterozygous BC1F1 plants. Background selection with 173 polymorphic SSR primers covering all the 21 chromosomes was also carried out, in the foreground-selected BC1F1 plants. BC1F2 plants were selected by ascertaining the presence of Pina-D1a (positive selection) and absence of Pina-D1b (negative selection). Using the approach of positive, negative and background selection with molecular markers, 15 BC1F2 and 31 BC2F1 plants were finally selected. The 15 BC1F2 plants were selfed and the 31 BC2F1 plants were further backcrossed and selfed to raise BC3F1 and BC2F2 progenies, respectively. A part of the BC2F2 seed of each of the 31 plants was analyzed for grain hardness index (GHI) with single-kernel characterization system. The GHI varied from 12.1 to 37.1 in the seeds borne on the 31 BC2F1 plants. The reasons for this variation and further course of action are discussed.

A set of 286 recombinant inbred lines (RILs) along with the parents and a popular wheat variety in India were grown for two consecutive years at three locations belonging to the two major wheat growing zones of India and evaluated for four grain quality traits. Rare recombinants with high trait value appeared for protein content (PC), thousand-kernel weight (TKW), sedimentation value (SV), and kernel hardness (KH). The magnitude of environmental effects was more pronounced than genotypic effects and genotype-environment interaction (GEI). The cumulative contribution of environment and GEI components to the total variance was highest in the expression of PC followed by TKW, SV, and KH. The top five percent (14 RILs) of genotypes with high trait value were subjected to Eberhart and Russell (1966) (ER), genotype and genotype-environment (GGE) and additive main effects and multiplicative interaction (AMMI) stability models. Five RILs were identified as stable in all the three stability models. RIL61 with 38.8%, RIL101 with 8.9%, RIL226 with 26.1% superiority over check variety were the most stable genotypes in all the three stability models for PC, TKW and KH, respectively. RIL113 was found to be stable genotype in ER and GGE models, whereas, RIL231 was the most stable genotype in AMMI and GGE models in the expression of SV. These common stable genotypes with high trait value identified through ER, AMMI and GGE models could be potential donors in active breeding programs to develop high yielding wheat varieties with improved PC, TKW, SV and KH.

Markers linked to QTLs are useful in practical plant breeding, only if they get validated in genotypes of independent populations and diverse genetic backgrounds. 41 SSR markers reported linked to QTLs for grain iron (Fe) and zinc (Zn) concentration in wheat were analysed. Only 16 of them showed polymorphism and the remaining 25 turned out to be monomorphic in 48 wheat genotypes used in the present study. Single marker analysis (SMA) for the 16 polymorphic markers was carried out to assess the linkage between marker and the trait, based on which two markers (Xbarc186 and Xbarc74) for grain Fe concentration and three markers (Xgwm3, Xwms149 and Xgwm538) for grain Zn concentration were validated in the present study. The phenotypic variations explained by Xbarc186, Xbarc74, Xgwm3, Xwms149 and Xgwm538 were 40.2% and 19.8%, 10.7%, 21.7%, and 39.6%, respectively. The validation of these SSRs may be useful in breeding wheat with high grain Fe and Zn concentration.