• Energy Research

Two chickpea genotypes viz. Bhakar-2011 (desi) and Noor-2013 (kabuli) were sown in soil filled pots supplied with low (0.3 mg kg-1) and high (3 mg kg-1 soil) zinc (Zn) under control (70% water holding capacity and 25/20 °C day/night temperature), drought (35% water holding capacity) and heat (35/30 °C day/night temperature) stresses. Drought and heat stresses reduced rate of photosynthesis, photosystem II efficiency, plant growth and Zn uptake in chickpea. Low Zn supply exacerbated adverse effects of drought and heat stresses in chickpea, and caused reduction in plant biomass, carbon assimilation, antioxidant activity, impeded Zn uptake and enhanced oxidative damage. However, adequate Zn supply ameliorated adverse effect of drought and heat stresses in both chickpea types. The improvements were more in desi than kabuli type. Adequate Zn nutrition is crucial to augment growth of chickpea plants under high temperature and arid climatic conditions.

Les températures ambiantes devraient augmenter à l'avenir pour plusieurs raisons associées aux changements climatiques mondiaux. Ces augmentations de température peuvent provoquer un stress thermique - une grave menace pour la production végétale dans la plupart des pays. Les légumineuses sont bien connues pour leur impact sur la durabilité agricole ainsi que pour leurs avantages nutritionnels et sanitaires. Le stress thermique pose des défis pour les cultures de légumineuses et a des effets délétères sur la morphologie, la physiologie et la croissance reproductive des plantes. Le stress à haute température pendant la phase de reproduction devient une contrainte sérieuse pour la productivité des légumineuses à grains à mesure que leur culture s'étend à des environnements plus chauds et que la variabilité de la température augmente en raison du changement climatique. La période de reproduction est vitale dans le cycle de vie de toutes les plantes et est sensible au stress à haute température car divers processus métaboliques sont affectés négativement pendant cette phase, ce qui réduit le rendement des cultures. Les légumineuses alimentaires exposées à un stress à haute température pendant la reproduction montrent un avortement des fleurs, une infertilité du pollen et des ovules, une fertilisation altérée et un remplissage réduit des graines, ce qui entraîne des graines plus petites et de mauvais rendements. Grâce à diverses techniques d'élevage, la tolérance à la chaleur des principales légumineuses peut être améliorée pour améliorer les performances sur le terrain. Les approches Omics démêlent différents mécanismes sous-jacents à la thermotolérance, ce qui est impératif pour comprendre les processus de réponses moléculaires au stress à haute température. Se prevé que las temperaturas ambientales aumenten en el futuro debido a varias razones asociadas con los cambios climáticos globales. Estos aumentos de temperatura pueden causar estrés por calor, una grave amenaza para la producción de cultivos en la mayoría de los países. Las legumbres son bien conocidas por su impacto en la sostenibilidad agrícola, así como por sus beneficios nutricionales y para la salud. El estrés por calor impone desafíos para los cultivos de leguminosas y tiene efectos perjudiciales sobre la morfología, la fisiología y el crecimiento reproductivo de las plantas. El estrés por altas temperaturas durante la etapa reproductiva se está convirtiendo en una grave limitación para la productividad de las leguminosas de grano a medida que su cultivo se expande a ambientes más cálidos y la variabilidad de la temperatura aumenta debido al cambio climático. El período reproductivo es vital en el ciclo de vida de todas las plantas y es susceptible al estrés por altas temperaturas, ya que varios procesos metabólicos se ven afectados negativamente durante esta fase, lo que reduce el rendimiento de los cultivos. Las leguminosas alimentarias expuestas al estrés por altas temperaturas durante la reproducción muestran aborto de flores, infertilidad de polen y óvulos, fertilización deficiente y menor llenado de semillas, lo que lleva a semillas más pequeñas y rendimientos deficientes. A través de diversas técnicas de mejoramiento, se puede mejorar la tolerancia al calor en las principales leguminosas para mejorar el rendimiento en el campo. Los enfoques de OMICS desentrañan diferentes mecanismos subyacentes a la termotolerancia, que es imprescindible para comprender los procesos de las respuestas moleculares al estrés por altas temperaturas. Ambient temperatures are predicted to rise in the future owing to several reasons associated with global climate changes. These temperature increases can cause heat stress- a severe threat to crop production in most countries. Legumes are well-known for their impact on agricultural sustainability as well as their nutritional and health benefits. Heat stress imposes challenges for legume crops and has deleterious effects on the morphology, physiology and reproductive growth of plants. High-temperature stress during the reproductive stage is becoming a serious constraint to the productivity of grain legumes as their cultivation expands to warmer environments and temperature variability increases due to climate change. The reproductive period is vital in the life cycle of all plants and is susceptible to high-temperature stress as various metabolic processes are adversely impacted during this phase, which reduces crop yield. Food legumes exposed to high-temperature stress during reproduction show flower abortion, pollen and ovule infertility, impaired fertilization, and reduced seed filling, leading to smaller seeds and poor yields. Through various breeding techniques, heat tolerance in major legumes can be enhanced to improve performance in the field. Omics approaches unravel different mechanisms underlying thermotolerance, which is imperative to understand the processes of molecular responses towards high-temperature stress. من المتوقع أن ترتفع درجات الحرارة المحيطة في المستقبل بسبب عدة أسباب مرتبطة بالتغيرات المناخية العالمية. يمكن أن تسبب هذه الزيادات في درجة الحرارة إجهادًا حراريًا - وهو تهديد خطير لإنتاج المحاصيل في معظم البلدان. تشتهر البقوليات بتأثيرها على الاستدامة الزراعية بالإضافة إلى فوائدها الغذائية والصحية. يفرض الإجهاد الحراري تحديات على محاصيل البقوليات وله آثار ضارة على التشكل وعلم وظائف الأعضاء والنمو التناسلي للنباتات. أصبح الإجهاد الناجم عن ارتفاع درجة الحرارة خلال مرحلة التكاثر عائقًا خطيرًا أمام إنتاجية البقوليات من الحبوب مع توسع زراعتها إلى بيئات أكثر دفئًا وزيادة تقلب درجات الحرارة بسبب تغير المناخ. تعتبر فترة التكاثر حيوية في دورة حياة جميع النباتات وهي عرضة للإجهاد في درجات الحرارة العالية حيث تتأثر عمليات التمثيل الغذائي المختلفة سلبًا خلال هذه المرحلة، مما يقلل من غلة المحاصيل. تظهر البقوليات الغذائية المعرضة لإجهاد درجة حرارة عالية أثناء التكاثر إجهاض الزهور، وعقم حبوب اللقاح والبويضة، وضعف الإخصاب، وانخفاض حشو البذور، مما يؤدي إلى بذور أصغر ومحاصيل ضعيفة. من خلال تقنيات التكاثر المختلفة، يمكن تعزيز تحمل الحرارة في البقوليات الرئيسية لتحسين الأداء في هذا المجال. تكشف مناهج أوميكس عن الآليات المختلفة الكامنة وراء التسامح الحراري، وهو أمر حتمي لفهم عمليات الاستجابات الجزيئية نحو الإجهاد في درجات الحرارة العالية.

The present study was conducted to evaluate the effect of two non ionic surfactants (Tween 80 and Triton X-100), a biosurfactant (Lecithin), and randomly methylated-β-cyclodextrins (RAMEB) on the remediation of pyrene from soil planted with tall fescue (Festuca arundinacea). Soils with pyrene concentration of about 243 mg kg(-1) was grown with tall fescue and were individually amended with 0, 200, 600, 1000, and 1500 mg kg(-1) of Tween 80, Triton X-100, biosurfactant, and RAMEB. The results show that all surfactants significantly increased plant biomass compared to unamended soil. Dehydrogenase activity was also stimulated as a result of surfactant addition. Only 3.9 and 3.2 % of pyrene was decreased in the uncovered and covered abiotic sterile control, suggesting that microbial degradation was the main removal mechanism of pyrene from soil. In the planted treatment receiving no surfactant, the remediation of pyrene was 45 % which is significantly higher than that of corresponding unplanted control soil, suggesting that the cultivation of tall fescue alone could enhance the overall remediation of pyrene in soil. All surfactants had significantly higher rates of pyrene remediation compared to the unamended planted soil. Generally, RAMEB displayed the highest remediation rates, i.e., 64.4-79.1 % followed by the Triton X-100, i.e., 60.1-74.8 %. The positive impact of surfactants on pyrene remediation could possibly be because of their capacities to increase its bioavailability in soil. The evidence from this study suggests that the addition of surfactants could enhance phytoremediation of PAHs polluted soil.

Climate change can decrease the global maize productivity and grain quality. Maize crop requires an optimal temperature for better harvest productivity. A suboptimal temperature at any critical stage for a prolonged duration can negatively affect the growth and yield formation processes. This review discusses the negative impact of temperature extremes (high and low temperatures) on the morpho-physiological, biochemical, and nutritional traits of the maize crop. High temperature stress limits pollen viability and silks receptivity, leading to a significant reduction in seed setting and grain yield. Likewise, severe alterations in growth rate, photosynthesis, dry matter accumulation, cellular membranes, and antioxidant enzyme activities under low temperature collectively limit maize productivity. We also discussed various strategies with practical examples to cope with temperature stresses, including cultural practices, exogenous protectants, breeding climate-smart crops, and molecular genomics approaches. We reviewed that identified quantitative trait loci (QTLs) and genes controlling high- and low temperature stress tolerance in maize could be introgressed into otherwise elite cultivars to develop stress-tolerant cultivars. Genome editing has become a key tool for developing climate-resilient crops. Moreover, challenges to maize crop improvement such as lack of adequate resources for breeding in poor countries, poor communication among the scientists of developing and developed countries, problems in germplasm exchange, and high cost of advanced high-throughput phenotyping systems are discussed. In the end, future perspectives for maize improvement are discussed, which briefly include new breeding technologies such as transgene-free clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas)-mediated genome editing for thermo-stress tolerance in maize.

Production of phosphorus efficient crop cultivars can increase food productivity and decrease environmental pollution. Categorization of existing germplasm is a prerequisite to develop P efficient crop cultivars. For first experiment, 30 wheat genotypes were grown in hydroponics with two P levels (i.e., deficit, 20 μm KH2PO4 and adequate, 200 μm KH2PO4). Genotypes differed significantly for various P efficiency parameters. Two genotypes (Dirk and Bhakkar-02) showed < 25% decrease in growth at P deficiency. Genotype Seher-06 proved to be inefficient. Twelve selected genotypes based on the first experiment were sown in soil with two P levels (0 and 30 mg P kg-1) till maturity. As expected, genotypes differed for grain yield at both P levels. The efficient cultivars selected on the basis of both absolute and relative dry matter production at both P levels such as Dirk. Genotypes were grouped into three, four and nine classes on the basis of various parameters for P efficiency as proposed by different researchers. Most genotypes behaved in a similar fashion by different categorization methods and also at different P supply. The method to categorize the genotypes into three classes and plotting them into 9 classes proposed by Gill and his coworkers, is the best to differentiate the minor differences in genotypes. At least three different parameters at both P regimes should be used. The parameters may vary as per objectives of the study and/or growth conditions.

AbstractBACKGROUNDZinc (Zn) deficiency and low soil fertility are the major factors responsible for low yield in chickpea. This study was conducted to evaluate the effect of Zn application and plant growth‐promoting bacteria (PGPB) (endophyte Enterobacter sp. MN17) on soil health and aboveground biomass of desi and kabuli chickpea under natural field conditions. Zn was applied as seed priming (0.001 mol L−1) and soil application (10 kg Zn ha−1) with and without PGPB. To determine the impacts of Zn and PGPB on soil biological health, soil microbial biomass carbon (MBC) and soil extracellular enzyme activities were analyzed at two growth stages: vegetative (90 days after sowing) and maturity (163 days after sowing).RESULTSThe highest aboveground biomass (5.1 t ha−1) was recorded with Zn seed priming + PGPB in kabuli chickpea and in desi chickpea (4.8 t ha−1) with Zn seed priming only. The application of Zn significantly increased soil MBC, which was higher in kabuli (795 and 731 μg C g−1) compared to desi chickpea (655 and 533 μg C g−1) at both vegetative and reproductive growth stages, respectively. The highest extracellular soil enzyme activities, – β‐glucosidase (4758 nmol g−1 h−1), acid phosphatase (5508 nmol g−1 h−1), chitinase (5997 nmol g−1 h−1) and leucine aminopeptidase (993 nmol g−1 h−1) – were recorded with Zn seed priming. Of the chickpea types, kabuli chickpea had higher soil extracellular enzyme activities in the rhizosphere than desi chickpea.CONCLUSIONZn seed priming along with PGPB application may improve soil health and chickpea biomass in marginal soils. © 2021 Society of Chemical Industry.

The rice–wheat cropping system is the main food bowl in Asia, feeding billions across the globe. However, the productivity and long-term sustainability of this system are threatened by stagnant crop yields and greenhouse gas emissions from flooded rice production. The negative environmental consequences of excessive nitrogen fertilizer use are further exacerbating the situation, along with the high labor and water requirements of transplanted rice. Residue burning in rice has also severe environmental concerns. Under these circumstances, many farmers in South Asia have shifted from transplanted rice to direct-seeded rice and reported water and labor savings and reduced methane emissions. There is a need for opting the precision agriculture techniques for the sustainable management of nutrients. Allelopathic crops could be useful in the rotation for weed management, the major yield-reducing factor in direct-seeded rice. Legume incorporation might be a viable option for improving soil health. As governments in South Asia have imposed a strict ban on the burning of rice residues, the use of rice-specific harvesters might be a pragmatic option to manage rice residues with yield and premium advantage. However, the soil/climatic conditions and farmer socio-economic conditions must be considered while promoting these technologies in rice-wheat system in South Asia.