Maize is one of the most important field crops considering its utilization as food, feed, fodder, and biofuel. However, the sustainability of its production is under serious threat of heat and drought stresses, as these stresses could hamper crop growth, causing a significant loss to kernel yield. The research study was carried out at Maize and Millets Research Institute, Yusafwala-Sahiwal for two consecutive spring seasons (2019–20 and 2020–21) under a split-split plot design. The current study explained the individual and combined effects of drought and heat stresses on morphology, phenology, physiology, reactive oxygen species (stocktickerROS), antioxidant status, and kernel quality traits in four indigenous (YH-5482, YH-5427, YH-5404, and YH-1898) and one multinational maize hybrid (P-1543). Stress treatments, i.e., drought, heat, and drought+heat, were applied ten days before tasseling and lasted for 21 days. The results revealed the incidence of oxidative stress due to overproduction of Hydrogen peroxide; H2O2 (control: 1.9, heat+drought: 5.8), and Malondialdehyde; stocktickerMDA (control: 116.5, heat+drought: 193), leading to reduced photosynthetic ability (control: 31.8, heat:16.5), alterations in plant morphology, decrease in kernel yield (control: 10865 kg ha–1, heat+drought: 5564 kg ha–1), and quality-related traits. Although all the stress treatments induced the accumulation of stress-responsive osmolytes and enzymatic antioxidants to cope with the negative impact of osmotic stress, the effect of combined drought + heat stress was much higher. The overall performance of indigenous maize hybrid YH-5427 was much more promising than the other hybrids, attributed to its better tolerance of drought and heat stresses. Such stress tolerance was attributed to maintaining photosynthetic activity, a potent antioxidant and osmolyte-based defense mechanisms, and minimum reductions in yield-related traits, which assured the maximum kernel yield under all stress treatments.

Combining ability analysis has a key position in rapeseed breeding. To estimate the combining ability effects for yield controlling traits in rapeseed, three testers and five lines were crossed using line × tester design in randomized complete block design with three replications. Mean sum of squares of analysis of variances for genotypes were significant for all of the traits; indicating the presence of significant genetic variation. All the interactions between lines and testers exhibited significant results of mean sum of squares for combining ability. Line 'Duncled' was found good general combiner for decreased Plant height (PH:-2.0), Days taken to 50% flowering (DF: -15.8) and Days taken to maturity (DM:-3.4) while tester 'Punjab Sarson" for increased Number of seed/siliqua (SS: 2.2), Number of siliquae/plant (SP: 2.2) and decreased DF (-3.0) traits. Significant general and specific combining ability effects were observed. The best hybrid combination on the basis of specific combining ability effects was "Durre-NIFA × ZN-M-6" for Seed yield/plant (SY: 2.7), DF (-6.1) and DM (-3.5). PH (-0.2), Siliqua length (SL: -0.1), SS (-0.03) and SY (0.2) showed non-additive genetic effects. The half of the characters revealed additive and remaining half showed non-additive genetic effects. The present study unveiled the importance of both type of genetic effects demanding the application of integrated breeding approaches for exploiting the variability. 'Punjab Sarson × ZN-M-6' exposed maximum SS (30) and SP (837). Maximum SY (75.9g) and minimum DF (64) were showed by 'Legend × Duncled'. The present research delivers valuable information of genotypes for promoting yield by means of improving yield related characters.

Crop production is a serious challenge to provide food for the 10 billion individuals forecasted to live across the globe in 2050. The scientists’ emphasize establishing an equilibrium among diversity and quality of crops by enhancing yield to fulfill the increasing demand for food supply sustainably. The exploitation of genetic resources using genomics and metabolomics strategies can help generate resilient plants against stressors in the future. The innovation of the next-generation sequencing (NGS) strategies laid the foundation to unveil various plants’ genetic potential and help us to understand the domestication process to unmask the genetic potential among wild-type plants to utilize for crop improvement. Nowadays, NGS is generating massive genomic resources using wild-type and domesticated plants grown under normal and harsh environments to explore the stress regulatory factors and determine the key metabolites. Improved food nutritional value is also the key to eradicating malnutrition problems around the globe, which could be attained by employing the knowledge gained through NGS and metabolomics to achieve suitability in crop yield. Advanced technologies can further enhance our understanding in defining the strategy to obtain a specific phenotype of a crop. Integration among bioinformatic tools and molecular techniques, such as marker-assisted, QTLs mapping, creation of reference genome, de novo genome assembly, pan- and/or super-pan-genomes, etc., will boost breeding programs. The current article provides sequential progress in NGS technologies, a broad application of NGS, enhancement of genetic manipulation resources, and understanding the crop response to stress by producing plant metabolites. The NGS and metabolomics utilization in generating stress-tolerant plants/crops without deteriorating a natural ecosystem is considered a sustainable way to improve agriculture production. This highlighted knowledge also provides useful research that explores the suitable resources for agriculture sustainability.

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Please use the following format when citing the article: Mumtaz A., Sadaqat H. A., Saeed M., Yousaf M. I., Shehzad A., Ahmed H. AbstractThe domestic production of edible oil meets only 20.23% of the demand in Pakistan, and domestic oil production needs to be increased. Thanks to its short life cycle, high yield and yellow seed colour, oilseed rape (Brassica rapa L.) is a potentially useful source to fill the gap between production and consumption. This study was designed to ascertain the genetic expression of descriptive and seed yield-related traits in four B. rapa accessions (UAF-11, Toria, BSA and TP-124-1) and their hybrid progenies obtained from complete diallel mating crossings. Heterosis and heterobeltiosis were computed for these traits. Seed colour was varying shades of brown and showed Mendelian genetics. Seed shape was consistently round in all lines, and leaf hairiness was a characteristic of all crosses including self. Each parent line had a particular leaf shape as elliptic, pandurate, lanceolate and ovate, and no intermediate or new shapes were observed in F 1 . Leaf colour was varying shades of green. Seed shape, leaf shape and leaf colour were under digenic control with no epistatic or maternal effects. Leaf shape showed multiple allelism. Seed shape showed no variations. Leaf hairiness was dominant and under monogenic control. Number of siliqua/primary branches of plant, number of siliqua/secondary branches of plant and total number of siliqua/plant directly affect seed yield of plant while effect of plant height is indirect. Variability was observed in heterosis and heterobeltiosis for all traits. UAF-11 and its crosses with Toria and TP-124-1 and their reciprocals were identified as the best hybrid progenies for future breeding efforts. Our results for the traits, compared here will, hopefully, facilitate future efforts to select productive B. rapa accessions for breeding programs aimed at optimizing heterosis.