Showing papers in "Crop & Pasture Science in 2022"

Agronomic biofortification and productivity of wheat with soil zinc and diazotrophic bacteria in tropical savannah

Abstract: Agronomic biofortification of staple food with zinc (Zn) in combination with diazotrophic bacteria is one sustainable and feasible strategy to improve plant nutrition, nutrient use efficiency and production and combat Zn malnutrition in human beings. Wheat (Triticum aestivum L.) is a staple food of the global population and has a prospective role in agronomic Zn biofortification. In this context, the effect of diazotrophic bacterial inoculations in seeds (no inoculation – Control, Azospirillum brasilense, Bacillus subtilis and Pseudomonas fluorescens) in association with soil Zn application (without (0) and 8 kg/ha) was evaluated on Zn nutrition, growth, yield and Zn use efficiencies in wheat in the 2019 and 2020 cropping seasons. Soil Zn application in combination with P. fluorescens improved Zn concentration in the leaf (38.8 and 45.9%), shoot (25.0 and 31%) and grain (34.0 and 33.3%) with greater shoot dry matter (9.4 and 9.9%) and grain yield (20.3 and 20.6%) as compared to controls in 2019 and 2020 respectively. Also, inoculation of P. fluorescens with Zn application improved Zn shoot and grain accumulation, zinc use efficiency, recovery and utilisation efficiency. With daily wheat consumption, these improvements would be associated with a with higher estimated Zn intake for the human population globally and within Brazil. However, agro-physiological efficiency was increased with inoculation of Bacillus subtilis. Therefore, inoculation of P. fluorescens in association with soil Zn application is recommended for agronomic biofortification, and to increase productivity and Zn use efficiencies in wheat in the tropical savannah of Brazil.

Agronomic biofortification and productivity of wheat with soil zinc and diazotrophic bacteria in tropical savannah

Abstract: Abstract. Agronomic biofortification of staple food with zinc (Zn) in combination with diazotrophic bacteria is one sustainable and feasible strategy to improve plant nutrition, nutrient use efficiency and production and combat Zn malnutrition in human beings. Wheat (Triticum aestivum L.) is a staple food of the global population and has a prospective role in agronomic Zn biofortification. In this context, the effect of diazotrophic bacterial inoculations in seeds (no inoculation – Control, Azospirillum brasilense, Bacillus subtilis and Pseudomonas fluorescens) in association with soil Zn application (without (0) and 8 kg/ha) was evaluated on Zn nutrition, growth, yield and Zn use efficiencies in wheat in the 2019 and 2020 cropping seasons. Soil Zn application in combination with P. fluorescens improved Zn concentration in the leaf (38.8 and 45.9%), shoot (25.0 and 31%) and grain (34.0 and 33.3%) with greater shoot dry matter (9.4 and 9.9%) and grain yield (20.3 and 20.6%) as compared to controls in 2019 and 2020 respectively. Also, inoculation of P. fluorescens with Zn application improved Zn shoot and grain accumulation, zinc use efficiency, recovery and utilisation efficiency. With daily wheat consumption, these improvements would be associated with a with higher estimated Zn intake for the human population globally and within Brazil. However, agro-physiological efficiency was increased with inoculation of Bacillus subtilis. Therefore, inoculation of P. fluorescens in association with soil Zn application is recommended for agronomic biofortification, and to increase productivity and Zn use efficiencies in wheat in the tropical savannah of Brazil.

Silicon and zinc nanoparticles-enriched miscanthus biochar enhanced seed germination, antioxidant defense system, and nutrient status of radish under NaCl stress

Abstract: Context Soil salinity mitigation with nanoparticles enriched biochar (Bc) can be a better strategy to resolve the uprising threat against food security. Aim The present study was designed to prepare silicon nanoparticles enriched biochar (Si-En-Bc) and zinc nanoparticles enriched biochar (Zn-En-Bc), which may not only reduced the toxic effects of NaCl stress on initial growth of radish crop but also improved its physiology and defensive mechanism. Method Seeds were germinated in pots with six treatments under normal and NaCl stress, (100 mM NaCl), Zn-En-Bc (1% w/w), and Si-En-Bc (1% w/w). Twenty days old seedlings were harvested and their fresh weight and various germination and biochemical parameters were tested. Key results A significant reduction in malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents was observed with Si-En-Bc + NaCl relative to NaCl stress. It might be due to the significant increase in the antioxidants such as superoxide dismutase (SOD) (42%), ascorbate peroxidase (APX) (38.7%), catalase (CAT) (30.9%) and shoot phenolics (59%) with Si-En-Bc + NaCl over NaCl stress. Application of Zn-En-Bc also caused a maximum increase in root and shoot Zn concentration (76.8 and 54.9%, respectively) under NaCl stress. Conclusions Hence, Si-En-Bc proved to be the best treatment for the radish plant to complete its early growth stage under NaCl stress while Zn-En-Bc not only compensated NaCl stress but also enhanced Zn availability. Implications This study implies that Si-En-Bc or Zn-En-Bc should be applied to the salt affected soil before the crop sowing so seedling can grow under the ameliorative effects of applied amendments. Also, Si-En-Bc or Zn-En-Bc should be tested on a degraded soils at larage scale such as field level.

Comparative effects of biochar and NPK on wheat crops under different management systems

Abstract: ABSTRACT As a multi-beneficial amendment, biochar is very useful to be applied for improving soil health and crop productivity. Therefore, this study was carried out to assess the influence of wood biochar and mineral nitrogen (N), phosphorus (P) and potassium (K) fertilisers viz, [(control; 100% NPK (120:90:60 kg ha−1); 75% NPK + 5 tonne biochar; 50% NPK + 10 tonne biochar; 25% NPK + 15 tonne biochar and 20 tonne biochar ha−1)] on wheat yield and soil properties under different management practices [(raised bed (more than 30 cm above the ground) and flat-bed)]. Split plot two factors randomised completed block (RCB) design with three replications were used where management practices were placed to main plot, while treatments were assigned to subplots. Maximum spike length, grain per spike, 1000 grain weight, grain and biological yield were obtained with application of 75% NPK + 5 tonne biochar ha−1 under both raised and flat-bed, which were statistically at par to 50% NPK + 10 tonne biochar ha−1. The grain and biological yield observed at 75% NPK + 5 tonne biochar and 50% NPK + 10 tonne biochar ha−1 were significantly higher than that of 20 tonne biochar ha−1. However, maximum soil organic matter, extractable P and K contents with slight increases in soil pH and EC was observed at 20 tonne biochar ha−1. Moreover, almost all agronomic parameters were significantly better in raised bed compared to flat-bed sowing. Hence, the present study suggested that 75% NPK + 5 tonne biochar ha−1 is suitable for improving wheat yield and soil properties.

Weed recognition using deep learning techniques on class-imbalanced imagery

Abstract: Context Most weed species can adversely impact agricultural productivity by competing for nutrients required by high-value crops. Manual weeding is not practical for large cropping areas. Many studies have been undertaken to develop automatic weed management systems for agricultural crops. In this process, one of the major tasks is to recognise the weeds from images. However, weed recognition is a challenging task. It is because weed and crop plants can be similar in colour, texture and shape which can be exacerbated further by the imaging conditions, geographic or weather conditions when the images are recorded. Advanced machine learning techniques can be used to recognise weeds from imagery. Aims In this paper, we have investigated five state-of-the-art deep neural networks, namely VGG16, ResNet-50, Inception-V3, Inception-ResNet-v2 and MobileNetV2, and evaluated their performance for weed recognition. Methods We have used several experimental settings and multiple dataset combinations. In particular, we constructed a large weed-crop dataset by combining several smaller datasets, mitigating class imbalance by data augmentation, and using this dataset in benchmarking the deep neural networks. We investigated the use of transfer learning techniques by preserving the pre-trained weights for extracting the features and fine-tuning them using the images of crop and weed datasets. Key results We found that VGG16 performed better than others on small-scale datasets, while ResNet-50 performed better than other deep networks on the large combined dataset. Conclusions This research shows that data augmentation and fine tuning techniques improve the performance of deep learning models for classifying crop and weed images. Implications This research evaluates the performance of several deep learning models and offers directions for using the most appropriate models as well as highlights the need for a large scale benchmark weed dataset.

Digital applications and artificial intelligence in agriculture toward next-generation plant phenotyping

Abstract: In the upcoming years, global changes in agricultural and environmental systems will require innovative approaches in crop research to ensure more efficient use of natural resources and food security. Cutting-edge technologies for precision agriculture are fundamental to improve in a non-invasive manner, the efficiency of detection of environmental parameters, and to assess complex traits in plants with high accuracy. The application of sensing devices and the implementation of strategies of artificial intelligence for the acquisition and management of high-dimensional data will play a key role to address the needs of next-generation agriculture and boosting breeding in crops. To that end, closing the gap with the knowledge from the other ‘omics’ sciences is the primary objective to relieve the bottleneck that still hinders the potential of thousands of accessions existing for each crop. Although it is an emerging discipline, phenomics does not rely only on technological advances but embraces several other scientific fields including biology, statistics and bioinformatics. Therefore, establishing synergies among research groups and transnational efforts able to facilitate access to new computational methodologies and related information to the community, are needed. In this review, we illustrate the main concepts of plant phenotyping along with sensing devices and mechanisms underpinning imaging analysis in both controlled environments and open fields. We then describe the role of artificial intelligence and machine learning for data analysis and their implication for next-generation breeding, highlighting the ongoing efforts toward big-data management.

Seed priming with boron and

Abstract: Context The production of chickpea (Cicer arietinum L.) is negatively affected by boron (B) deficiency. In Pakistan, the crop grown under B deficiency produces grains with low B concentration. Application of B-tolerant bacteria (BTB) is a promising option to improve B supply to plants grown under B deficiency. Aims This study was focused on determining the appropriate concentration of B for seed priming, and its effects with BTB inoculation on growth, productivity and grain B concentration of chickpea. Methods Chickpea seeds were primed in aerated solutions of B concentrations in the range 0.01–0.5% (w/v), with hydroprimed and dry seeds as controls. Concentrations >0.1% proved toxic and seeds failed to germinate. Hence, B was further diluted to concentrations in the range 0.0001–0.1%. Pots containing chickpea seeds were divided into two sets having all B treatments. One set was inoculated with BTB (5 mL per pot of pure Bacillus sp. MN54 culture at 10 9 cfu mL−1); the other set was not inoculated. Key results Seed priming with B along with BTB inoculation improved stand establishment, growth, nodulation, yield and grain B concentration of chickpea. Seed priming treatments with B at 0.001% and 0.0001% along with BTB inoculation were most effective for improving stand establishment, seedling growth and grain yield, whereas 0.1% B was more effective for improving grain B concentration. Conclusions Seed priming with 0.001% B along with inoculation of Bacillus sp. MN54 improved seed germination, nodulation, yield and grain B concentration of chickpea under B-deficiency conditions. Implications Seed inoculation with BTB i.e., Bacillus sp. MN54 coupled with seed priming in 0.001% B solution is a viable option to improve yield and grain B concentration of chickpea grown on B-deficient soils.

Insect detection from imagery using YOLOv3-based adaptive feature fusion convolution network

Abstract: Context Insects are a major threat to crop production. They can infect, damage, and reduce agricultural yields. Accurate and fast detection of insects will help insect control. From a computer algorithm point of view, insect detection from imagery is a tiny object detection problem. Handling detection of tiny objects in large datasets is challenging due to small resolution of the insects in an image, and other nuisances such as occlusion, noise, and lack of features. Aims Our aim was to achieve a high-performance agricultural insect detector using an enhanced artificial intelligence machine learning technique. Methods We used a YOLOv3 network-based framework, which is a high performing and computationally fast object detector. We further improved the original feature pyramidal network of YOLOv3 by integrating an adaptive feature fusion module. For training the network, we first applied data augmentation techniques to regularise the dataset. Then, we trained the network using the adaptive features and optimised the hyper-parameters. Finally, we tested the proposed network on a subset dataset of the multi-class insect pest dataset Pest24, which contains 25 878 images. Key results We achieved an accuracy of 72.10%, which is superior to existing techniques, while achieving a fast detection rate of 63.8 images per second. Conclusions We compared the results with several object detection models regarding detection accuracy and processing speed. The proposed method achieved superior performance both in terms of accuracy and computational speed. Implications The proposed method demonstrates that machine learning networks can provide a foundation for developing real-time systems that can help better pest control to reduce crop damage.

Molecular characterisation of

Abstract: Phenylalanine ammonia lyase (PAL) is the first enzyme in the phenylpropanoid pathway and plays a critical role in plant growth, development and stress defence. However, there have been few reports of the PAL gene family in lucerne (also known as alfalfa, Medicago sativa L.), one of the most important forage legume species worldwide. In this study, we report that PAL in lucerne is encoded by a family of seven genes: MsPAL1–MsPAL7. Furthermore, a comprehensive genome-wide bioinformatics analysis of the MsPAL gene family is presented, including chromosomal locations, phylogenetic relationships, gene structures and conserved motifs. The cis-elements and potential biological functions of these genes were investigated, revealing the potential roles of MsPAL members in response to various stresses. RT-qPCR results showed that the expression of MsPAL6 was significantly upregulated under both salinity- and waterlogging-stress conditions. Other MsPAL members such as MsPAL1 and MsPAL2 were downregulated under saline conditions and upregulated significantly after waterlogging stress. Our findings provide useful information for further practical analyses and for the genetic improvement of abiotic stress tolerance of lucerne.

Imaging-based screening of wheat seed characteristics towards distinguishing drought-responsive Iranian landraces and cultivars

Abstract: Abstract. Improving drought endurance in wheat needs high-throughput screening of yield components including seed volume, area, and weight, all of which are very effortful, time-consuming, and visually mostly infeasible. Imaging-based screening presents an opportunity for more exact/rapid analysis of seed morphometric traits. Therefore, this study was aimed at evaluating the phenotypic diversity of wheat seeds under rain-fed and well-watered conditions by using image analysis. From our observations, the criteria Feret (largest axis length) and MaxR (radius of the enclosing circle centered at the middle of mass) exhibited that grain length is less affected by drought. In the rain-fed environment, seed weight had the highest correlation with seed volume (r = 0.76**) and area (r = 0.76**). The correlation of 1000-grain weight with aspect ratio (r = –0.22**) and Rroundness (r = –0.21**) was negative and also non-significant (P > 0.05). The PCA and cluster analysis highlights the MinR (radius of the inscribed circle centered at the middle of mass), Area, Circ (Circularity), ArEquivD (area equivalent diameter), thickness, and seed volume characteristics can be used as useful parameters to identify genotypes suitable for planting in a rain-fed environment. The relative importance of traits for 1000-grain weight in the neural network displayed that the greatest impact in the rain-fed environment was related to seed volume, area, and MBCRadius (radius of the minimal bounding circle). Overall, our findings permitted the formation of a morphometric seed database for the conservation and characterisation of wheat germplasm.

Molecular characterisation of PAL gene family reveals their role in abiotic stress response in lucerne (Medicago sativa)

Abstract: ABSTRACT Phenylalanine ammonia lyase (PAL) is the first enzyme in the phenylpropanoid pathway and plays a critical role in plant growth, development and stress defence. However, there have been few reports of the PAL gene family in lucerne (also known as alfalfa, Medicago sativa L.), one of the most important forage legume species worldwide. In this study, we report that PAL in lucerne is encoded by a family of seven genes: MsPAL1-MsPAL7. Furthermore, a comprehensive genome-wide bioinformatics analysis of the MsPAL gene family is presented, including chromosomal locations, phylogenetic relationships, gene structures and conserved motifs. The cis-elements and potential biological functions of these genes were investigated, revealing the potential roles of MsPAL members in response to various stresses. RT-qPCR results showed that the expression of MsPAL6 was significantly upregulated under both salinity- and waterlogging-stress conditions. Other MsPAL members such as MsPAL1 and MsPAL2 were downregulated under saline conditions and upregulated significantly after waterlogging stress. Our findings provide useful information for further practical analyses and for the genetic improvement of abiotic stress tolerance of lucerne.

Growth, metal partitioning and antioxidant enzyme activities of mung beans as influenced by zinc oxide nanoparticles under cadmium stress

Abstract: Abstract Context. Cadmium (Cd) toxicity and zinc (Zn) deficiency are of major concerns for crop growth and quality. Moreover, their interactive effects exert some controversial reports. Aims. The effects of zinc oxide nanoparticles (ZnO NPs) and Cd on growth, physiology, and metal distribution in mung beans (Vigna radiata L.) was investigated. Methods. Seven-day-old seedlings were treated with Zn (0, 1, 2, 4, 8, 16 and 32 μM) and Cd (0, 0.5, 1 μM) for 14 days. Key results. Photosynthetic pigments, antioxidant enzyme activities, dry matter yield and metal concentration in tissues were significantly influenced by ZnO NPs and Cd. Considered on its own as a main effect, Zn application (16 μM) enhanced its accumulation in roots, stem and leaf by about 33-fold (314 mg kg−1), 10-fold (60.6 mg kg−1) and 17-fold (110.8 mg kg−1), respectively, compared to control. However, accumulation was slower for interactions with Cd. While leaf Zn increased approximately 27 times (180 mg kg−1) at 32 μM Zn, its interactions with lower and higher Cd increased only 6-fold (41.2 mg kg−1) and 3-fold (21.4 mg kg−1), respectively. Added ZnO NPs up to 4 μM under Cd contamination elevated the leaf Cd, which was restricted by higher supply. However, Cd accumulation in stem and root consistently rose, indicating a synergistic effect. ZnO NPs induced an upregulation of antioxidant enzymes to avert oxidative stress and maintain growth performance. Implications. These findings may be suitable for formulating nanomaterials of desired particle sizes and testing on other crop to remediate Cd.

Mineral biofortification and metal/metalloid accumulation in food crops: recent research and trends (Part I)

Abstract: Human health is directly related to the quality of food consumed. Copper (Cu), iron (Fe), manganese (Mn), selenium (Se) and zinc (Zn) aremicronutrients that are often deficient in diets consumed around the world (Ritchie and Roser 2017). Plants are the direct or indirect sources of these micronutrients for human consumption. The micronutrient concentrations in plant-based foods are, therefore, the indicators of the balanced and healthy diets of humans.With plant-based foods not providing sufficient micronutrients to meet the human needs, the agricultural sector needed to address this challenge. Micronutrient biofortification of food crops, especially of staple cereal grains, is a promising approach to mitigate the widespread micronutrient deficiencies in susceptible human populations in both developing and developed countries. Several agronomic and genetic approaches have been suggested to increase micronutrient density in edible plant parts. In the last two decades, the research on various aspects of micronutrient biofortification is one of the major foci of plant scientists around the world. Contamination of natural resources and the resultant accumulation of toxic metal(loid)s such as arsenic (As) and cadmium (Cd) in food crops has increased dietary intake of these contaminants (Afonne and Ifediba 2020). Exposure to their high concentration may lead to both acute and chronic toxicities in human population, even when living far away from the contamination sources. This is quite an opposite challenge to the micronutrient deficiencies in human populations. In living cells, the potentially toxic metal(loid)s are absorbed via the transporters of essential minerals. This makes it very challenging for plant breeders to develop crop cultivars that can differentiate between the essential and toxic elements. Given the prevailing scenario, it is urgent to develop the strategies for producing micronutrient-dense plant-based foods with the concentrations of heavy metal(loid)s below the maximum permissible levels. The special issue on Mineral Biofortification and Metal/Metalloid Accumulation in Food Crops was aimed at publishing the latest research on agronomic and genetic biofortification, and metal/metalloid accumulation in food crops. Following is a brief description of the articles included in part one of the special issue.

Current status of and future opportunities for digital agriculture in Australia

Abstract: ABSTRACT In Australia, digital agriculture is considered immature and its adoption ad hoc, despite a relatively advanced technology innovation sector. In this review, we focus on the technical, governance and social factors of digital adoption that have created a disconnect between technology development and the end user community (farmers and their advisors). Using examples that reflect both successes and barriers in Australian agriculture, we first explore the current enabling technologies and processes, and then we highlight some of the key socio-technical factors that explain why digital agriculture is immature and ad hoc. Pronounced issues include fragmentation of the innovation system (and digital tools), and a lack of enabling legislation and policy to support technology deployment. To overcome such issues and increase adoption, clear value propositions for change are necessary. These value propositions are influenced by the perceptions and aspirations of individuals, the delivery of digitally-enabled processes and the supporting legislative, policy and educational structures, better use/conversion of data generated through technology applications to knowledge for supporting decision making, and the suitability of the technology. Agronomists and early adopter farmers will play a significant role in closing the technology-end user gap, and will need support and training from technology service providers, government bodies and peer-networks. Ultimately, practice change will only be achieved through mutual understanding, ownership and trust. This will occur when farmers and their advisors are an integral part of the entire digital innovation system.

Resistance to NaCl salinity is positively correlated with iron and zinc uptake potential of wheat genotypes

Abstract: ABSTRACT Context. Soil salinity is a serious environmental issue that is drastically reducing crop productivity via limiting the uptake of important micronutrients including iron (Fe) and zinc (Zn). Aims. To identify the wheat genotypes with better Fe and Zn uptake potential under saline conditions. Methods. The seedlings of eight wheat genotypes (SARC-1, SARC-2, SARC-3, SARC-4, SARC-5, SARC-6, SARC-7 and SARC-8) were exposed to salinity (100 mM NaCl), deficiency of Fe and Zn (one-fourth of the control) and their combination of salinity and deficiency of Fe and Zn, created usingHoagland's nutrient solution for 28 days. Key Results. It was noticed that root and shoot growth of all the genotypes decreased due to salinity and nutrient (Fe and Zn) deficiency, and even higher in their combined treatment. The concentration of Na increased while K decreased under both salinity alone and it's combination with nutrient deficiency. The concentrations and uptake of Fe and Zn greatly decreased in the combinedapplication of salinity and nutrient deficiency followed by nutrient deficiency and saline treatments. Multivariate analysis showed that Na uptake was the major reason for the limited growth and nutrient uptake by wheat genotypes. Conclusions. SARC-5 was the most sensitive genotype against salinity and nutrient deficiency. In contrast, SARC-1 was the most tolerant genotype against salinity, whichaccumulated the highest contents of both Fe and Zn. Among the eight genotypes used in the present study, SARC-1 is the most suitable genotype for cultivation on Zn and Fe deficient saline soils. Implications. The obtained results would be very helpful for ensuring food security and quality in salt affected areas.

Molecular diversity and nutriment studies of common bean (

Abstract: The diverse microclimatic belts of the Western Himalayan region of India are considered hot spots for genetic diversity of common bean (Phaseolus vulgaris L.). Western Himalayan beans are known for various agronomically superior/important traits including unique aroma, taste and cooking quality. In the present study, 25 unlinked genomic simple sequence repeat (SSR) markers distributed across the common bean genome were used to assess the genetic/allelic diversity among and within populations belonging to the Jammu and Kashmir regions of the Western Himalayas. These two regions are considered most important hot-spots for common bean diversity in western-Himalayas. The analysis of genotypic data of SSR markers revealed a total of 263 alleles with an average of 10.52 alleles per locus. The genetic diversity analysis revealed higher variability in bean landraces belonging to Jammu region (He = 0.73) as compared to genotypes from Kashmir region (He = 0.647) and some exotic genotypes (0.71). The genotypes were also phenotyped for four important nutritional traits and the analysis of trait data revealed that sugar content was highest in common bean genotypes from Jammu region, while protein, starch and phenol content were highest in exotic common bean genotypes. Therefore, the superiority of common bean germplasm from Jammu region may be due to a higher level of allelic diversity, more private alleles and higher sugar content. The diverse genotypes based on genotypic data and trait performance will prove useful in future breeding programs aimed at enhancing nutritional contents of common bean varieties.

Appraisal of functional significance of sulfur assimilatory products in plants under elevated metal accumulation

Abstract: ABSTRACT Plants varyingly serve as control agents for heavy metal loads in environmental compartments, including soils, by accumulating and partitioning most heavy metals in their organs. However, by doing this wonderful job, the plant health and productivity get affected because of the elevated cellular heavy metals. Therefore, exploration of approaches for strengthening plant's tolerance to cellular heavy metals is very imperative. As an indispensable macronutrient in plants, sulfur (S) is widely known to assist numerous plant functions and is also argued as vital element for various plant metabolic processes both in normal and stressed conditions. However, the discussion on the heavy metal-specific roles of S-containing compounds in plants have been considered least. In this paper, the aspects discussed included the following: (1) heavy metals and their relation with plants; and nutrient-management and S in control of metal stress-impacts in plants are introduced; (2) major insights into S-assimilation and -assimilatory products are overviewed; (3) important roles of assimilatory products in plant tolerance to common heavy metals are highlighted, and (4) metal-specific influence on assimilatory products in plants are discussed.

Characterisation of biochar produced from two types of chestnut shells for use in remediation of cadmium- and lead-contaminated soil

Abstract: ABSTRACT China is the major producer of chestnut, with 1.84 million tons of chestnut production, resulting in an enormous waste of chestnut shells. In the current study, shell biochar (SBC) was produced using the inside shell covering fruit, and the outside shell with thorns was used to produce thorn biochar (TBC). Both types of biochar were characterised through Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). These analytical results showed a more obvious smooth surface and micro-pore structure in SBC. The vibration of C=O/C=C and C–O (phenolic) showed a significant difference between the two types of biochar. Sorption experiments indicated that the adsorption capacity of the different types of biochar for cadmium (Cd) did not differ significantly, whereas the adsorption capacity of TBC for lead was better than that of SBC. In the pakchoi cultivation experiment (28 days), the application of TBC (1.5%) promoted plant shoot weight, root weight, shoot length and root length by 465%, 143%, 109% and 97% respectively. The application of biochar effectively increased soil pH and reduced the bioavailability and migration of heavy metals. Besides, membrane integrity and chlorophyll content were enhanced because of the alleviation of oxidative stress. Noticeably, application of TBC (0.1% and 1.5%) reduced the Cd concentration in the root by 40–60%, and enhanced accumulation of Pb by 75–191%. Overall, our study demonstrated that 1.5% TBC has promising potential for remediating Cd-contaminated soil. Our study has demonstrated the remediation potential of chestnut and provided a clue for sustainable management of chestnut shell waste for further development of chestnut resources.

Growth, metal partitioning and antioxidant enzyme activities of mung beans as influenced by zinc oxide nanoparticles under cadmium stress

Abstract: Context Cadmium (Cd) toxicity and zinc (Zn) deficiency are of major concerns for crop growth and quality. Moreover, their interactive effects exert some controversial reports. Aims The effects of zinc oxide nanoparticles (ZnO NPs) and Cd on growth, physiology, and metal distribution in mung beans (Vigna radiata L.) was investigated. Methods Seven-day-old seedlings were treated with Zn (0, 1, 2, 4, 8, 16 and 32 μM) and Cd (0, 0.5, 1 μM) for 14 days. Key results Photosynthetic pigments, antioxidant enzyme activities, dry matter yield and metal concentration in tissues were significantly influenced by ZnO NPs and Cd. Considered on its own as a main effect, Zn application (16 μM) enhanced its accumulation in roots, stem and leaf by about 33-fold (314 mg kg−1), 10-fold (60.6 mg kg−1) and 17-fold (110.8 mg kg−1), respectively, compared to control. However, accumulation was slower for interactions with Cd. While leaf Zn increased approximately 27 times (180 mg kg−1) at 32 μM Zn, its interactions with lower and higher Cd increased only 6-fold (41.2 mg kg−1) and 3-fold (21.4 mg kg−1), respectively. Added ZnO NPs up to 4 μM under Cd contamination elevated the leaf Cd, which was restricted by higher supply. However, Cd accumulation in stem and root consistently rose, indicating a synergistic effect. ZnO NPs induced an upregulation of antioxidant enzymes to avert oxidative stress and maintain growth performance. Implications These findings may be suitable for formulating nanomaterials of desired particle sizes and testing on other crop to remediate Cd.

Silicon and zinc nanoparticles-enriched miscanthus biochar enhanced seed germination, antioxidant defense system, and nutrient status of radish under NaCl stress

Abstract: ABSTRACT Context. Soil salinity mitigation with nanoparticles enriched biochar (Bc) can be a better strategy to resolve the uprising threat against food security. Aim. The present study was designed to prepare silicon nanoparticles enriched biochar (Si-En-Bc) and zinc nanoparticles enriched biochar (Zn-En-Bc), which may not only reduced the toxic effects of NaCl stress on initial growth of radish crop but also improved its physiology and defensive mechanism. Method. Seeds were germinated in pots with six treatments under normal and NaCl stress, (100 mM NaCl), Zn-En-Bc (1% w/w), and Si-En-Bc (1% w/w). Twenty days old seedlings were harvested and their fresh weight and various germination and biochemical parameters were tested. Key results. A significant reduction in malondialdehyde (MDA) and hydrogen peroxide (H2O2) contents was observed with Si-En-Bc + NaCl relative to NaCl stress. It might be due to the significant increase in the antioxidants such as superoxide dismutase (SOD) (42%), ascorbate peroxidase (APX) (38.7%), catalase (CAT) (30.9%) and shoot phenolics (59%) with Si-En-Bc + NaCl over NaCl stress. Application of Zn-En-Bc also caused a maximum increase in root and shoot Zn concentration (76.8 and 54.9%, respectively) under NaCl stress. Conclusions. Hence, Si-En-Bc proved to be the best treatment for the radish plant to complete its early growth stage under NaCl stress while Zn-En-Bc not only compensated NaCl stress but also enhanced Zn availability. Implications. This study implies that Si-En-Bc or Zn-En-Bc should be applied to the salt affected soil before the crop sowing so seedling can grow under the ameliorative effects of applied amendments. Also, Si-En-Bc or Zn-En-Bc should be tested on a degraded soils at larage scale such as field level.

Morpho-colorimetric seed traits for the discrimination, classification and prediction of yield in wheat genotypes under rainfed and well-watered conditions

Abstract: Context Morphometric digital analysis of plant seeds enables taxonomic discrimination of species based on morpho-colorimetric traits, and may be used to classify genotypes of wheat (Triticum aestivum L.). Aims This study was focused on the isolation and classification of cultivars and landraces of Iranian wheat based on morpho-colorimetric traits, and the prediction of yield and seedling vigour based on these traits. Methods In total, 133 wheat genotypes (91 native landraces and 42 cultivars) were evaluated by alpha lattice design in two crop years (2018–19 and 2019–20) under rainfed and conditions. After seed harvesting, 40 morpho-colorimetric traits of wheat seeds were measured by imaging. Seed colour, morphometric seed, seed vigour and yield were also assessed. Key results Using linear discriminant analysis based on morpho-colorimetric traits, wheat cultivars and landraces were separated with high validation percentage (90% in well-watered and 98.6% in rainfed conditions). Morpho-colorimetric traits L, Whiteness index, Chroma, a, Feret and Rectang were found to be the most discriminant variables in the rainfed field. In analysis based on seed colour according to descriptors of the International Union for the Protection of New Varieties of Plants and International Board for Plant Genetic Resources, wheat genotypes were classified into four groups with high accuracy by using linear discriminant analysis. Specifically, 97.3% could be identified as yellow and 99.7% as medium-red wheat groups. Conclusions Our observations suggest that seed digital analysis is an affordable and valuable approach for evaluating phenotypic variety among a large number of wheat genotypes. Morphometric analysis of cultivars and native populations can provide an effective step in classifying genotypes and predicting yield and seedling vigour. Implications Morphometric databases will help plant breeders when selecting genotypes in breeding programs.

Yield, zinc efficiencies and biofortification of wheat with zinc sulfate application in soil and foliar nanozinc fertilisation

Abstract: Abstract ContextAgronomic biofortification of wheat (Triticum aestivum L.) with zinc (Zn) is an effective approach to increase grain Zn concentration and productivity and alleviate Zn malnutrition in humans. Foliar Zn application is an alternative strategy to endorse soil Zn deficiency with better grain Zn partitioning. AimsThis study aimed to better understand dose management of soil and foliar Zn application in wheat for biofortification. MethodsThe objectives was to evaluate the effect of foliar applied nano Zn doses (0, 0.75, 1.5, 3 and 6 kg/ha (zinc oxide, ZnO) 50% at tillering and 50% at grain filling in combination) with soil Zn application (0 and 8 kg/ha, as zinc sulfate) on growth, nutrition, Zn use efficiencies, intake and yield biofortification of wheat in 2019 and 2020 under Brazilian savanna. Key resultsCombined foliar and soil Zn application increased shoot and grains Zn concentration and accumulation with greater dry matter (9.8 and 10.6%) and grain yield (9.8 and 11%) of wheat as compared to control in 2019 and 2020 respectively. Zinc use efficiency (ZnUE), Zn utilisation efficiency and applied Zn recovery improved with soil Zn application and 2.5 kg/ha foliar nano Zn, but decreased with further increase in foliar Zn application. Zn sulfate stood out for increasing crop productivity while foliar spray with nano Zn for better grains biofortification of wheat. ConclusionsSoil Zn application along with 3 kg/ha of foliar nano Zn increased plant and grains Zn concentration and accumulation, dry matter, grain yield, Zn partitioning index and Zn intake in wheat in tropical conditions of Brazil. ImplicationsThe combined application of soil and foliar Zn in harsh tropical savannah condition could better improve Zn nutrition, crop growth, and productivity with better Zn biofortification and intake of wheat.

Digital applications and artificial intelligence in agriculture toward next-generation plant phenotyping

Abstract: ABSTRACT In the upcoming years, global changes in agricultural and environmental systems will require innovative approaches in crop research to ensure more efficient use of natural resources and food security. Cutting-edge technologies for precision agriculture are fundamental to improve in a non-invasive manner, the efficiency of detection of environmental parameters, and to assess complex traits in plants with high accuracy. The application of sensing devices and the implementation of strategies of artificial intelligence for the acquisition and management of high-dimensional data will play a key role to address the needs of next-generation agriculture and boosting breeding in crops. To that end, closing the gap with the knowledge from the other ‘omics’ sciences is the primary objective to relieve the bottleneck that still hinders the potential of thousands of accessions existing for each crop. Although it is an emerging discipline, phenomics does not rely only on technological advances but embraces several other scientific fields including biology, statistics and bioinformatics. Therefore, establishing synergies among research groups and transnational efforts able to facilitate access to new computational methodologies and related information to the community, are needed. In this review, we illustrate the main concepts of plant phenotyping along with sensing devices and mechanisms underpinning imaging analysis in both controlled environments and open fields. We then describe the role of artificial intelligence and machine learning for data analysis and their implication for next-generation breeding, highlighting the ongoing efforts toward big-data management.

Resistance to NaCl salinity is positively correlated with iron and zinc uptake potential of wheat genotypes

Abstract: Context Soil salinity is a serious environmental issue that is drastically reducing crop productivity via limiting the uptake of important micronutrients including iron (Fe) and zinc (Zn). Aims To identify the wheat genotypes with better Fe and Zn uptake potential under saline conditions. Methods The seedlings of eight wheat genotypes (SARC-1, SARC-2, SARC-3, SARC-4, SARC-5, SARC-6, SARC-7 and SARC-8) were exposed to salinity (100 mM NaCl), deficiency of Fe and Zn (one-fourth of the control) and their combination of salinity and deficiency of Fe and Zn, created usingHoagland’s nutrient solution for 28 days. Key Results It was noticed that root and shoot growth of all the genotypes decreased due to salinity and nutrient (Fe and Zn) deficiency, and even higher in their combined treatment. The concentration of Na increased while K decreased under both salinity alone and it's combination with nutrient deficiency. The concentrations and uptake of Fe and Zn greatly decreased in the combinedapplication of salinity and nutrient deficiency followed by nutrient deficiency and saline treatments. Multivariate analysis showed that Na uptake was the major reason for the limited growth and nutrient uptake by wheat genotypes. Conclusions SARC-5 was the most sensitive genotype against salinity and nutrient deficiency. In contrast, SARC-1 was the most tolerant genotype against salinity, whichaccumulated the highest contents of both Fe and Zn. Among the eight genotypes used in the present study, SARC-1 is the most suitable genotype for cultivation on Zn and Fe deficient saline soils. Implications The obtained results would be very helpful for ensuring food security and quality in salt affected areas.

Appraisal of functional significance of sulfur assimilatory products in plants under elevated metal accumulation

Abstract: Plants varyingly serve as control agents for heavy metal loads in environmental compartments, including soils, by accumulating and partitioning most heavy metals in their organs. However, by doing this wonderful job, the plant health and productivity get affected because of the elevated cellular heavy metals. Therefore, exploration of approaches for strengthening plant’s tolerance to cellular heavy metals is very imperative. As an indispensable macronutrient in plants, sulfur (S) is widely known to assist numerous plant functions and is also argued as vital element for various plant metabolic processes both in normal and stressed conditions. However, the discussion on the heavy metal-specific roles of S-containing compounds in plants have been considered least. In this paper, the aspects discussed included the following: (1) heavy metals and their relation with plants; and nutrient-management and S in control of metal stress-impacts in plants are introduced; (2) major insights into S-assimilation and -assimilatory products are overviewed; (3) important roles of assimilatory products in plant tolerance to common heavy metals are highlighted, and (4) metal-specific influence on assimilatory products in plants are discussed.

Iron fortification of food crops through nanofertilisation

Abstract: Micronutrient deficiencies are a significant cause of malnutrition worldwide, particularly in developing countries, affecting nearly 1.8 billion people worldwide. Agriculture is the primary source of nutrients for humans, but the increasing population and reducing arable lands areas are putting the agricultural sector under pressure, particularly in developing and less developed countries, and calls for intensive farming to increase crop yield to overcome food and nutrients deficiency challenges. Iron is an essential microelement that plays a vital role in plant and human growth, and metabolism, but its deficiency is widely reported and affects nearly one-third of the world population. To combat micronutrient deficiency, crops must have improved nutritional qualities or be biofortified. Several biofortification programs with conventional breeding, biotechnological and agronomic approaches have been implemented with limited success in providing essential nutrients, especially in developing and under-developed countries. The use of nanofertilisers as agronomic biofortification method to increase yields and nutrients, micronutrient availability in soil and uptake in plant parts, and minimising the reliance on harmful chemical fertilisers is essential. Using nanoparticles as nanofertilisers is a promising approach for improving the sustainability of current agricultural practices and for the biofortification of food crop production with essential micronutrients, thus enhanced nutritional quality. This review evaluates the current use of iron nanofertilisers for biofortification in several food crops addressing critical knowledge gaps and challenges that must be addressed to optimise the sustainable application.

Biochar actions for the mitigation of plant abiotic stress

Abstract: ABSTRACT Abiotic stresses are the dominant constraints to successful crop production in the modern era. Over the past few decades, researchers have devised various techniques to ease the effects of abiotic stresses on crop plants. Biochar is a vital eco-friendly biostimulant that mostly increases crop production and alleviates the adverse effects of different abiotic stresses. It improves crop yield as a fertiliser and soil quality as a soil conditioner. Biochar amendment in the soil is gaining popularity these days. This is because it improves the physio-biochemical and biological properties of soil. Biochar enhances abiotic stress tolerance as well as growth and yield of plants by modulating ionic homeostasis, photosynthetic apparatus, antioxidant machineries, reducing heavy metal accumulations and oxidative damages. However, the stress-relieving roles of biochar have not been thoroughly assembled. This review summarises current reports of biochar application and discusses the potential roles of biochar amendment in soil for crop growth and production under stress and non-stress conditions. This review also covers the possible mechanisms for how abiotic stress mitigation is accomplished in plants and the limitations and prospects of biochar application in agriculture.

Marker-assisted selection and validation of DNA markers associated with cadmium content in durum wheat germplasm

Abstract: Abstract. Cadmium (Cd) is a non-essential heavy metal having toxic effects on all living organisms. Durum wheat (Triticum durum Desf.) is widely used in human diets but has the potential to accumulate Cd. It also has a high level of genetic diversity, which may be exploited to develop cultivars with low Cd content. We aimed to perform marker-assisted selection and validate previously identified Cd markers in durum wheat germplasm for use in the investigation of accessions that accumulate low grain Cd content. We assessed 130 durum wheat accessions phenotypically and using three different molecular markers. Grain Cd contents of the studied germplasm varied 4.91-fold (26.2–128.7 μg/kg) with an average of 58.2 μg/kg. Landraces showed lower average values of grain Cd content than cultivars. Three molecular markers (usw47, Cad-5B and KASP marker Cad-5B) were used to differentiate high and low Cd accumulating lines. Results showed high correlation and successfully classified the accessions to the expected high or low Cd level; 87 accessions showed the low Cd alleles, and 43 accessions the high Cd alleles, except for five accessions with the usw47 marker that showed heterozygous status. A significant correlation coefficient (r = 0.944*) was observed among the three molecular markers. Based on molecular markers, 96.2% of the accessions were classified accurately. The KASP assay was highly effective in successfully separating low from high Cd content accessions and could be used as a molecular tool in durum wheat breeding programs, with less cost and time, targeting reduced grain Cd levels. The results of this study will allow durum wheat breeders to accelerate their progress to select suitable genotypes with the desired alleles.

Marker-assisted selection and validation of DNA markers associated with cadmium content in durum wheat germplasm

Abstract: Cadmium (Cd) is a non-essential heavy metal having toxic effects on all living organisms. Durum wheat (Triticum durum Desf.) is widely used in human diets but has the potential to accumulate Cd. It also has a high level of genetic diversity, which may be exploited to develop cultivars with low Cd content. We aimed to perform marker-assisted selection and validate previously identified Cd markers in durum wheat germplasm for use in the investigation of accessions that accumulate low grain Cd content. We assessed 130 durum wheat accessions phenotypically and using three different molecular markers. Grain Cd contents of the studied germplasm varied 4.91-fold (26.2–128.7 μg/kg) with an average of 58.2 μg/kg. Landraces showed lower average values of grain Cd content than cultivars. Three molecular markers (usw47, Cad-5B and KASP marker Cad-5B) were used to differentiate high and low Cd accumulating lines. Results showed high correlation and successfully classified the accessions to the expected high or low Cd level; 87 accessions showed the low Cd alleles, and 43 accessions the high Cd alleles, except for five accessions with the usw47 marker that showed heterozygous status. A significant correlation coefficient (r = 0.944*) was observed among the three molecular markers. Based on molecular markers, 96.2% of the accessions were classified accurately. The KASP assay was highly effective in successfully separating low from high Cd content accessions and could be used as a molecular tool in durum wheat breeding programs, with less cost and time, targeting reduced grain Cd levels. The results of this study will allow durum wheat breeders to accelerate their progress to select suitable genotypes with the desired alleles.