Wheat (Triticum aestivum L.), a vital staple crop, faces mounting challenges in ensuring global food security. This study aimed to develop solid stemmed wheat varieties fortified with multiple disease-resistance genes to combat disease and lodging challenges. Solid stem trait from select donors was transferred into contemporary Indian bread wheat cultivars. Additionally, through marker assisted backcrossing (MABC) techniques, resistant genes targeting leaf, stem, yellow rust, and powdery mildew were also incorporated into those backgrounds. Molecular markers confirmed the presence of solid stem and targeted resistance genes, ensuring the reliability of newly developed lines. These lines were assessed for solid stem characteristics to evaluate their performance across diverse regions. Field assessments conducted for disease screening in Wellington identified wheat varieties that exhibit resistance to both rusts and powdery mildew. Phenotypic screening for lodging and thermo tolerance highlighted the resilience of wheat lines with solid pith, emphasizing their potential role in mitigating climate change impacts. The study underscores the efficacy of backcross breeding and molecular tools in developing lodging resistant and thermo tolerant wheat varieties with enhanced rust-resistance, contributing to sustainable wheat production systems.

Rust diseases, caused by fungal pathogens, are a significant threat to global wheat production, including in India. The 2NvS translocation from Aegilops ventricosa, carrying the Lr37 + Sr38 + Yr17 gene cluster, has been crucial in developing rust-resistant wheat varieties. In this study, conventional backcross breeding was initially employed to integrate this gene cluster into ten Indian bread wheat cultivars, leading to the development of BC7F8 near-isogenic lines (NILs) with rust resistance. Comprehensive phenotyping at both juvenile and mature plant stages was done to select for desirable traits. However, this method was time-consuming and dependent on consistent disease pressure. The development of NIL’s took almost a decade and by the time the recurrent parents chosen were no longer in cultivation. To overcome these challenges, marker-assisted backcross breeding was subsequently employed, utilizing the VENTRIUP/LN2 molecular marker to verify the presence of the gene cluster which is more efficient and reliable in selecting desired traits. This approach enabled the efficient introgression of desirable traits into modern wheat varieties such as HD 2733, PBW 343, DBW 39, HD 2967, and HW 2045, specifically targeting the North Eastern Plain Zone of India. By shifting from conventional to marker-assisted backcross breeding using the VENTRIUP/LN2 marker, this study introduced a novel method that accelerated the development of rust-resistant lines, enhancing wheat production in rust-prone regions.

Stem rust is one of the major diseases threatening wheat production globally. To identify novel resistance quantitative trait loci (QTLs), we performed 35K Axiom Array SNP genotyping assays on an association mapping panel of 400 germplasm accessions, including Indian landraces, in conjunction with phenotyping for stem rust at seedling and adult plant stages. Association analyses using three genome wide association study (GWAS) models (CMLM, MLMM, and FarmCPU) revealed 20 reliable QTLs for seedling and adult plant resistance. Among these 20 QTLs, five QTLs were found consistent with three models, i.e., four QTLs on chromosome 2AL, 2BL, 2DL, and 3BL for seedling resistance and one QTL on chromosome 7DS for adult plant resistance. Further, we identified a total of 21 potential candidate genes underlying QTLs using gene ontology analysis, including a leucine rich repeat receptor (LRR) and P-loop nucleoside triphosphate hydrolase, which have a role in pathogen recognition and disease resistance. Furthermore, four QTLs (Qsr.nbpgr-3B_11, QSr.nbpgr-6AS_11, QSr.nbpgr-2AL_117-6, and QSr.nbpgr-7BS_APR) were validated through KASP located on chromosomes 3B, 6A, 2A, and 7B. Out of these QTLs, QSr.nbpgr-7BS_APR was identified as a novel QTL for stem rust resistance which has been found effective in both seedling as well as the adult plant stages. Identified novel genomic regions and validated QTLs have the potential to be deployed in wheat improvement programs to develop disease resistant varieties for stem rust and can diversify the genetic basis of resistance.

An in vitro pollen germination protocol for Triticale, the man-made cereal, has been reported. Triticale pollen may be classified as recalcitrant pollen as it is difficult to germinate on artificial medium. Using this pollen germination medium (PGM), viability and pollen vigour of triticale lines may be tested within 10–15 min. PGM used for triticale consisted of 19

Leaf rust is one of the important diseases limiting global wheat production and productivity. To identify quantitative trait nucleotides (QTNs) or genomic regions associated with seedling and adult plant leaf rust resistance, multilocus genome-wide association studies (ML-GWAS) were performed on a panel of 400 diverse wheat genotypes using 35 K single-nucleotide polymorphism (SNP) genotyping assays and trait data of leaf rust resistance. Association analyses using six multi-locus GWAS models revealed a set of 201 significantly associated QTNs for seedling and 65 QTNs for adult plant resistance (APR), explaining 1.98–31.72% of the phenotypic variation for leaf rust. Among these QTNs, 51 reliable QTNs for seedling and 15 QTNs for APR were consistently detected in at least two GWAS models and were considered reliable QTNs. Three genomic regions were pleiotropic, each controlling two to three pathotype-specific seedling resistances to leaf rust. We also identified candidate genes, such as leucine-rich repeat receptor-like (LRR) protein kinases, P-loop containing nucleoside triphosphate hydrolase and serine-threonine/tyrosine-protein kinases (STPK), which have a role in pathogen recognition and disease resistance linked to the significantly associated genomic regions. The QTNs identified in this study can prove useful in wheat molecular breeding programs aimed at enhancing resistance to leaf rust and developing next-generation leaf rust-resistant varieties.

In the context of the growing human population and climatic change, the current pace of wheat improvement is slow to meet future demand. This downturn partly owes to long generation time which demands technologies such as speed breeding (SB) that can accelerate plant growth and generation turnover. In field crops like wheat, SB is particularly contextual, because annual crop cycle is limited to one to two generations per year. To enable rapid generation advancement, SB uses extended photoperiod with supplementary lighting and temperature control to accelerate the development rate. However, if a part of these conditions is naturally available, such as temperature and humidity, SB can be launched with photoperiod manipulations alone. To test this hypothesis, we have conducted a study involving ten wheat cultivars, of which six were of Triticum aestivum and two each were of T. durum and T. dicoccum. The cultivars were subjected to 22 hours of extended light using red LED lamps and 2 hours of dark in a polyhouse, under natural temperature range of 17-22 degrees C and relative humidity of 75-80%. In all the cultivars, except HD 2967, plants reached heading in 36-42 days and physiological maturity in 67-73 days. In contrast, the same cultivars took 53-72 days for heading and 105-132 days for physiological maturity under field conditions. With SB, we could obtain five generations per year as against two generations under field conditions. Our results suggest that the customized SB has the potential for accelerated breeding as well as for integration with modern wheat improvement technologies.