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Synthetic fertilizer and herbicides encompass the largest share in nutrient and weed management on food grain crops that create serious environmental issues. Integrated nutrient and non-chemical weed management approaches may help to reduce the chemical load in the environment, maintaining higher weed control efficiency and yield. A field experiment was conducted for two consecutive monsoon seasons during 2015 and 2016 in farm fields to develop a profitable and sustainable rice production system through integrated nutrient and weed management practices. A varied combination of nutrients either alone or integrated with chemical and non-chemical weed management were tested on transplanted rice in a factorial randomized block design with three replications. The results showed that the integration of concentrated organic manures with chemical fertilizer effectively inhibited weed growth and nutrient removal. Integration of nutrient and weed management practices significantly enhanced 9% biomass growth, 10% yield of the rice crop along with 3–7% higher nutrient uptake. Brassicaceous seed meal (BSM) and neem cake also had some influence on weed suppression and economic return. Thus, the integrated nutrient and weed management practices in rice cultivation might be an effective way to achieve economic sustainability and efficient rice cultivation in eastern India. Shortages of farmyard manure and vermicompost could be supplemented by BSM and neem cake in the integrated module.

Plants are subjected to unregulated water loss from their surface by cuticular transpiration. Therefore, specific morphophysiological changes may occur during leaf development to eliminate water loss. This study aimed to examine the cuticular transpiration of 23 winter wheat genotypes and their wild-growing predecessors of the genus Aegilops, which were divided into three groups to demonstrate their diversity. The genotypes were sown in autumn and grown in regular field trials at the Research Institute of Plant Production in Piešťany, Slovakia. Cuticular transpiration and growth parameters were analyzed in the postanthesis growth stage. Gravimetric measurement of residual water loss was performed on detached leaves with a precisely measured leaf area. The lowest nonproductive transpiration values were observed in modern wheat genotypes, while higher cuticular transpiration was observed in a group of landraces. Aegilops species generally showed the highest cuticular transpiration with increased water loss, but the total water loss per plot was low due to the low leaf area of the wild wheat relatives. Some of the growth parameters showed a good correlation with cuticular transpiration (e.g., dry mass per plant), but direct relationships between leaf traits and cuticular transpiration were not observed. This study identified a high diversity in cuticular resistance to water loss in wheat and Aegilops accessions of different origins. The potential of identifying and exploiting genetic resources with favorable cuticular transpiration in crop breeding is discussed.

Aims Vegetation in ironstone outcrops is under potential environmental stressors. The aim of this work was to understand the relationships between the ecological strategies of species from ironstone outcrops in Brazil and their photosynthetic adjustments, and to contribute for the selection of species for the recovery of mined environments. Methods A total of 22 species belonging to 12 families were selected over canga vegetation. The physiological characteristics, chlorophyll a fluorescence and chlorophyll indices, were evaluated during the rainy and dry seasons. Analysis of competitor, stress-tolerator and ruderal (CSR) ecological strategies was performed during the rainy season for each species using functional leaf characteristics. Results The species presented the following ecological strategies: tolerance to stress (74.76%), competition (22.31%) and ruderality (2.93%). Despite a weak correlation between the ecological stress-tolerant strategy and photosynthetic variables, the low soil fertility and reduced rainfall during the dry season led to photochemical adjustments. The species were divided into five distinct groups based on the ability to use and dissipate excess light energy. Some species showed maintenance or increments in photochemical efficiency parameters, chlorophyll indices, and the capacity to avoid damage to the photosynthetic complex through a photoprotective process during the dry season. Conclusions The photochemical responses observed highlighted the diversity of adaptive strategies found in plant species from ironstone outcrops. The different photosynthetic adjustments are related to the competition capacity and stress tolerance mechanisms. Thus, the analyzed physiological parameters can be used for selecting plant species for the recovery of environments impacted by mining companies.

Environmental stresses including salinity, drought, cold, warmer temperatures, alterations in precipitation patterns, fluctuations of weather events, and increasing insect and disease infestations negatively affect crop production and nutritional values. This situation becomes further complicated due to the changing climatic conditions, thus raising concern about food security worldwide. Some worst‐case projections indicated that by 2100, CO2 concentrations will reach 950 parts per million, temperatures will climb by 3.5 to more than 8°C, sea level will rise by more than 2.4 meters, and the average farmland drought risk index will increase from 52.45 to 129. In addition, average precipitation will increase by 1%–3% in some areas and atmospheric water vapor will increase by 6%–7% for every degree of temperature rise. Rice (Oryza sativa L.) is a staple crop in many parts of the world. The main objective of this review is to highlight the prospects of rice for future climatic conditions. The present review depicts the advantages and prospects of rice and addresses why rice is a better option as a cereal crop for the future situations for food and nutritional sustainability. The impact of climate change on food and nutritional security can be mitigated by developing biotic and abiotic stress‐tolerant and biofortified rice varieties. These rice cultivars can withstand the negative effects of climate change while also meeting the nutritional needs of future generations. Furthermore, this review underlines the forthcoming issues and measures that should be addressed to assure a sustainable food and nutritional supply in the era of global climate change. Rice is a staple crop in many parts of the world and in this review, we highlighted the prospects of rice for future climatic conditions. In this review, we describe how rice could be a better option for future food and nutritional sustainability. This review describes the advantages and prospects of rice, to address why it is the best for the future situation and future questions and actions that are needed to develop a sustainable future food supply in light of global climate change.

Hydrogen peroxide (H2O2) and salicylic acid (SA) exhibit protective effects against a wide array of stresses. In this study, we investigated the relative efficacy of exogenous H2O2 and SA in conferring drought tolerance in rice (Oryza sativa L.). The experiment was repeated two times, firstly in a hydroponic system and secondly in soil. The results revealed that drought hampered germination indices, seedling growth, photosynthetic pigments, and water content, whereas increased proline content. It also triggered higher H2O2 production and consequently elevated lipid peroxidation, which is a particular indication of oxidative damage. However, exogenous H2O2 or SA treatment effectively alleviated oxidative damage in rice seedlings both in hydroponic and soil systems via upregulating antioxidant enzymes. Nevertheless, regulation of proline level and augmentation of plant-water status were crucial to confer drought tolerance. Exogenous H2O2 or SA also protected photosynthetic pigments from oxidative damage that might help to maintain normal photosynthesis under drought. Besides, 5 mmol/L H2O2 and 0.5 or 1 mmol/L SA showed similar effectiveness on mitigating drought stress. Finally, our findings suggest that exogenous H2O2 or SA could evenly be effectual in the amending growth of rice seedlings under drought conditions.

Heavy metal toxicity is one of the most devastating abiotic stresses. Heavy metals cause serious damage to plant growth and productivity, which is a major problem for sustainable agriculture. It adversely affects plant molecular physiology and biochemistry by generating osmotic stress, ionic imbalance, oxidative stress, membrane disorganization, cellular toxicity, and metabolic homeostasis. To improve and stimulate plant tolerance to heavy metal stress, the application of biostimulants can be an effective approach without threatening the ecosystem. Melatonin (N-acetyl-5-methoxytryptamine), a biostimulator, plant growth regulator, and antioxidant, promotes plant tolerance to heavy metal stress by improving redox and nutrient homeostasis, osmotic balance, and primary and secondary metabolism. It is important to perceive the complete and detailed regulatory mechanisms of exogenous and endogenous melatonin-mediated heavy metal-toxicity mitigation in plants to identify potential research gaps that should be addressed in the future. This review provides a novel insight to understand the multifunctional role of melatonin in reducing heavy metal stress and the underlying molecular mechanisms.

Increasing global population and climate change uncertainties have compelled increased photosynthetic efficiency and yields to ensure food security over the coming decades. Potentially, genetic manipulation and minimization of carbon or energy losses can be ideal to boost photosynthetic efficiency or crop productivity. Despite significant efforts, limited success has been achieved. There is a need for thorough improvement in key photosynthetic limiting factors, such as stomatal conductance, mesophyll conductance, biochemical capacity combined with Rubisco, the Calvin–Benson cycle, thylakoid membrane electron transport, nonphotochemical quenching, and carbon metabolism or fixation pathways. In addition, the mechanistic basis for the enhancement in photosynthetic adaptation to environmental variables such as light intensity, temperature and elevated CO2 requires further investigation. This review sheds light on strategies to improve plant photosynthesis by targeting these intrinsic photosynthetic limitations and external environmental factors.

This study aimed to characterise the specific phenotypic responses and the sensitivity of photosynthetic parameters to progressive drought in modern wheat genotypes. In pot experiments, we tested eight wheat genotypes (Triticum sp.) that differed in ploidy level and country of origin. Water stress was simulated by the restriction of irrigation, which led to a decreased leaf relative water content of up to 70%. During gradual dehydration, changes in the structure and function of photosystem II (PSII) were analysed using the fluorescence parameters derived from fast fluorescence kinetics (OJIP transient). The results indicated that a group of JIP test-based parameters demonstrated sensitivity to drought, including genotype-specific responses. Severe drought stress led to a decrease in the photochemical efficiency of PSII (Fv/Fm), a reduction in the number of active PSII reaction centers (RC/ABS) and a decrease in parameters, indicating overall photochemical performance at the PSII level (performance indices PIabs and PItot). These findings demonstrate that the approaches used in our experiments were useful and reliable in monitoring the physiological responses of individual varieties of wheat exposed to stress conditions, and they have application potential as selection criteria in crop breeding. The contribution of the high-temperature effects on the photochemical responses under water deficit conditions is also discussed.

Genetic diversity is a useful resource for crop improvement. In this study, a total of 28 rice genotypes were screened to isolate potential salt-tolerant genotypes at the seedling stage using hydroponic system. Different morpho-physiological indicators were used to classify tolerant and susceptible genotypes and biochemical determinants were dissected to clarify the underlying tolerance mechanism. Rice seedling were treated with two salinity levels (EC-1.1 dSm‒1 (control) and EC-7 dSm‒1) for 18 days. Salt stress resulted in significant decrease of growth and physiological traits in all genotypes; however, the lowest reduction was observed in some salt-tolerant genotypes namely Ghunsi, Nonabokra, Hogla, Holdegotal, Vusieri, and Kanchon. Cluster analysis considering percent reduction of growth parameters categorized the genotypes into four main sub-clusters and importantly, the salt-tolerant landraces were placed in the same cluster (cluster-II) with salt-tolerant check genotypes. The results of principle component analyses also demonstrated highly salt-tolerant genotypes were Vusieri > Nonabokra > Ghunsi > Hogla > Holdegotal > Kanchon. To explore the potential biochemical basis of salt stress tolerance, three tolerant genotypes were further characterized along with a salt-sensitive genotype. The higher K+/Na+ ratios noted for all salt-tolerant landraces thus indicating that the K+/Na+ ratio serves as a reliable indicator of salt tolerance in rice. The higher increment of proline content, catalase, ascorbate peroxidase activities, and comparatively lower accumulation of H2O2 and MDA were reported in salt-tolerant landraces as compared with salt-sensitive genotype. Therefore, these landraces could be utilized as promising genotypes as a source of salt-tolerant parents in the hybridization program for the development of high-yielding salt-tolerant rice variety as well as in isolating salt-tolerant genes.

Plant survival in response to freezing stress depends on the efficient activation of tolerance mechanisms. Fritillaria imperialis exposure to freezing stress enhanced signalling molecules Ca 2+ and H 2 O 2 along with overexpression of Ca 2+ signalling proteins (Ca 2+ dependent protein kinases, CPK), followed by upregulation of NHX1 (Na + /H + antiporter), LEA (late embryogenesis abundant proteins) and P5CS (1-pyrroline-5-carboxylate synthetase). Overexpression of OsCNGC6 was responsible for high accumulation Ca 2+ , Na + and K + . The NHX1 gene product transported Na + to vacuoles and increased cytosolic K + content to re-establish ionic homeostasis under stress conditions. The reduced water potential of leaves was due to high accumulation of osmolytes and ions. No changes were observed in relative water content of leaves, which might be correlated with overexpression of the LEA gene, which protects against dehydration. High accumulation of H 2 O 2 under freezing stress was responsible for activation of antioxidant systems involving SOD, phenols, anthocyanins, catalase and ascorbate peroxidase. Photosynthesis, suppressed in freezing-stressed plants, returned to normal levels after termination of freezing stress. Taken together, our findings suggest that Fritillaria efficiently tolerated freezing stress through induction of signalling mechanisms and overexpression of cold stress-responsive genes, and prevention of cold-induced water stress, oxidative stress and photosynthetic damage.