International Crops Research Institute for the Semi-Arid Tropics
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Applications of UAVs: Image-Based Plant Phenotyping
No full textPlant phenotyping plays an important role in the qualitative and quantitative assessment of plant growth in its growth environment. Traditional data-collection process used in plant breeding applications is mostly manual, time-consuming, labor-intensive, and highly subjective. Recent advancements in imaging sensors and platforms have significantly enhanced the speed and precision of image-based automated high-throughput plant phenotyping (HTPP). Current automated HTPP is mostly done in controlled environment where the plants are moved to phenotyping platforms. Such technologies are not feasible for open-field phenotyping. Satellite-based remote sensing has been used from decades but is not much effective in small-scale field phenotyping. Nowadays, satellite imagery with good resolution of up to few centimeters (~10–50 cm) is available, but due to fixed revisit time its temporal resolution is still limited. For crops’ trait estimation, high spatial, spectral, and temporal resolutions are mandatory. On the other hand, unmanned aerial vehicle (UAV)-drone-assisted image-based HTPP is current state-of-the-art for open-field phenotyping, and is known for providing data with high spatiotemporal resolution, with wide coverage in shorter duration. UAV (drone)-assisted HTPP is used in quantitative phenotyping for traits like plant height, biomass, and leaf area index, and qualitative phenotyping for traits like leaf nitrogen content; it is also used in biotic and abiotic stress quantification in plants. As of now the UAVs (drones) are popular for scouting and pesticide spraying in open field. The use of UAVs (drones) for phenotyping is a newer research area that is not matured enough till date. The main objective of this chapter is to explore the use of UAVs (drones) with different types of sensors mounted on it, for lean field phenotyping so that it will be used to assist the breeders in speeding up the selective breeding process using image-based HTPP with high precision and accuracy
Genetic gains in early maturing maize hybrids developed by the International Maize and Wheat Improvement Center in Southern Africa during 2000–2018
Get PDFGenetic gain estimation in a breeding program provides an opportunity to monitor breeding efficiency and genetic progress over a specific period. The present study was conducted to (i) assess the genetic gains in grain yield of the early maturing maize hybrids developed by the International Maize and Wheat Improvement Center (CIMMYT) Southern African breeding program during the period 2000–2018 and (ii) identify key agronomic traits contributing to the yield gains under various management conditions. Seventy-two early maturing hybrids developed by CIMMYT and three commercial checks were assessed under stress and non-stress conditions across 68 environments in seven eastern and southern African countries through the regional on-station trials. Genetic gain was estimated as the slope of the regression of grain yield and other traits against the year of first testing of the hybrid in the regional trial. The results showed highly significant (p< 0.01) annual grain yield gains of 118, 63, 46, and 61 kg ha−1 year−1 under optimum, low N, managed drought, and random stress conditions, respectively. The gains in grain yield realized in this study under both stress and non-stress conditions were associated with improvements in certain agronomic traits and resistance to major maize diseases. The findings of this study clearly demonstrate the significant progress made in developing productive and multiple stress-tolerant maize hybrids together with other desirable agronomic attributes in CIMMYT’s hybrid breeding program
Characteristics of natural and planted sandalwood-supporting soils in Seoni district, Madhya Pradesh
Get PDFTwo sandalwood-supporting pedons, one planted (P1) and other natural growing, were characterized in Seoni district of Madhya Pradesh. The solum depth of both the pedon was 30 cm underlain by weathered basalt beyond 50 cm. Pedon was dark reddish brown while P2 was characterized by dark reddish brown to dusky red. P2 had sandy clay texture (A1 horizon) and other horizons of both the pedons was associated
with clay texture. These soils had more than 35 cmol(p+)kg-1 CEC and dominance of smectite (>20%) followed by vermiculite. There was more than 20 per cent feldspar in Bw horizon of P1 while underlying horizon of P2 had 25 per cent quartz. The nearly neutral soils had more than 1.0 per cent organic carbon barring A2 horizon of P2. These calcareous soils were dominated by exchangeable Ca++ followed by
Mg++, Na+, K+ on exchange complex and grouped as Typic Haplustepts and Typic Ustorthents at subgroup level
Genome-Wide Identification of the Glycine-Rich RNA-Binding Protein Genes and Their Expression Analysis upon Aspergillus flavus Infection in Groundnut (Arachis hypogaea)
Get PDFAflatoxins, carcinogenic secondary metabolites produced by the Aspergillus fungi, pose a significant threat to groundnut, making them susceptible to infection and compromising their quality. Despite extensive breeding programs, the need for more durable resistance in groundnut germplasm remains a major challenge. Targeting susceptible genes favoring Aspergillus infection in groundnut could offer a promising strategy for achieving durable resistance. The glycine-rich RNA-binding protein (GR-RBP)-coding genes, known for their involvement in plant hypersensitivity and susceptibility to A. flavus, have been studied in model plants. However, there needs to be more understanding of the GR-RBP gene family in groundnut. In this study, twenty-three Arachis hypogaea GR-RBP (Ah.GR-RBP) genes were identified, and the chromosomal location, sub-cellular localization, and regulatory elements in the putative promoter region were analyzed. Expression analysis revealed that Ah.GR-RBP.1, Ah.GR-RBP.12, Ah.GR-RBP.3, and Ah.GR-RBP.15 showed higher expression in the susceptible genotype. This paper would help to provide knowledge on potential candidate target genes for precise breeding interventions for aflatoxin mitigation in groundnut
The genotypic variation in the positive response of sorghum to higher sowing density is linked to an increase in water use efficiency
Get PDFIn semi-arid tropical areas, sorghum is sown at very low planting densities. Hence, increasing plant density represents an opportunity to improve productivity. However, assessing the expected increase in water needs is critical prior to testing higher densities under rainfed conditions. This was tested with a panel of elite cultivars in field and lysimiter experiments, and testing the effects of two density treatment, high (HD, 22 plants.m-²) and low (LD, 11 plants.m-²), on grain and biomass yield and on water use and water use efficiency (WUE). Doubling the conventional sowing density significantly increased biomass and grain yield, with a genotypic variability in the biomass response. No link was found between the response to density and the maintenance of the tillering capacity, whereas the response to density was somewhat explained by a differential increase in the leaf area index under high density (r=0.43 P<0.05). Lysimeter experiments showed that, compared with the conventional density, the high-density treatment had 62% increase in biomass vs a 38% increase in water use, resulting in a 17% higher WUE on average of the genotypes tested. There was an appreciable genotypic variability in this degree of WUE increase under high density. The most striking result was the very tight positive link between the biomass response to density and the differential increase in WUE in the dry season (r=0.91 P<0.0001), whereas in the wet season this link was negative (r=-0.48 P<0.02). This work shows that intensifying sorghum production by increasing sowing density is possible, in the short term using cultivars that show the largest WUE increase under high density, in the longer term by breeding high-density adapted cultivars, targeting plant traits that explain the tight link between higher WUE and higher yield under high density
Biochar as a strategy to manage stem rot disease of groundnut incited by Sclerotium rolfsii
Get PDFDue to the pathogen’s ability to survive in the soil for longer durations, soil-borne diseases are often difficult to control. This study investigates the multifaceted impacts of biochar on the management of stem rot disease in groundnut and its influence on soil properties and microbial communities. The effects of biochar at different concentrations, such as 0%, 1%, 3%, and 5% on groundnut stem rot disease incited by Sclerotium rolfsii were evaluated thoroughly. Under laboratory conditions, biochar exhibited no direct inhibitory effects on S. rolfsii at varying concentrations but revealed an indirect suppression of sclerotial body production, suggesting a concentration-dependent influence on pathogen resting structures. Further, it was observed that biochar treatments effectively delayed symptom onset and reduced disease progression in groundnut plants, with significant variation observed among genotypes and biochar concentrations. Notably, interactions involving genotypes ICGV 171002 and ICGV 181035 with BC2 + Sr (3% conc. of biochar + S. rolfsii) and BC3 + Sr (5% conc. of biochar + S. rolfsii) treatments showed superior efficacy in disease reduction under controlled conditions. Field evaluations confirmed these findings, highlighting genotype-specific responses to biochar treatments. However, no significant difference was observed between BC2 + Sr (3%) and BC3 + Sr (5%) treatments in managing stem rot disease compared to controls. Biochar application significantly increased soil nutrient levels, including nitrogen, phosphorus, and potassium, and increased soil organic matter content, EC, pH, emphasizing its potential to improve soil fertility. Overall, these findings highlight the potential benefits of biochar for sustainable agriculture through disease management, soil nutrient enrichment, and microbial modulation, warranting further investigation into optimal application strategies across different agricultural contexts
Rice Bran Extraction and Stabilization Methods for Nutrient and Phytochemical Biofortification, Nutraceutical Development, and Dietary Supplementation
Get PDFRice is a global staple food crop for nearly half of the world's population. Rice bran along with the germ are essential components of whole-grain rice and have immense potential for enhancing human nutrition. Rice bran has a unique composition and distinct requirements for processing before it can be consumed by humans when compared with other cereal brans. The comprehensive overview and synthesis of rice bran processing include extending the shelf life for functional food product development and extraction of bioactive components. This narrative review highlights established and innovative stabilization approaches, including solvent extraction and enzymatic treatments, which are critical methods and technologies for wider rice bran availability. The nutrient and phytochemical profiles of rice bran may improve with new cultivar development and food-fortification strategies. The postharvest agricultural practices and processing techniques can reduce food waste while also supporting growers to produce novel pigmented cultivars that can enhance nutritional value for human health
Aflatoxin B1 Contamination Association with the Seed Coat Biochemical Marker Polyphenol in Peanuts Under Intermittent Drought
Get PDFAflatoxin B1 (AFB1) contamination (AC) increases as the severity of drought stress increases in peanuts. Identifying drought-tolerant (DT) genotypes with resistance to Aspergillus flavus colonization and/or infection may aid in developing peanuts resistant to aflatoxin contamination in the semi-arid tropics. The goal of this study is to identify DT genotypes with seed coat biochemical resistance to A. flavus infestation and aflatoxin contamination. Experiments were carried out at ICRISAT Sahelian Center; fifty-five genotypes were assessed under adjacent intermittent water-stressed (WS) conditions imposed from the 60th day after sowing to the maturity date and well-watered (WW) conditions in an alpha lattice design with two factors. The yield and its components, the incidence of A. flavus colonization, aflatoxin contamination, and seed coat total polyphenol (SCTPP) were investigated. Our findings show that the water deficit reduced the pod yield, seed yield, and haulm yield by up to 19.49%, 27.24%, and 22.07%, respectively, while it increased the number of immature pods per plant (IMPN) and the aflatoxin contamination by up to 67.16% and 54.95%, respectively. The drought tolerant genotypes ICG 2106, ICG 311, ICG 4684, ICG 4543, and ICG 1415 maintained a high yield, small number of IMPN under WS and low aflatoxin content variation between WW and WS. Our findings revealed that in the drought-tolerant genotypes ICG 1415, ICG 2106, ICG 311, ICG 4684, and ICG 4543, there was a significant relationship between the aflatoxin resistance and the seed coat total polyphenol under the two water treatments (r2 = 0.80; r2 = 0.82). This suggests that these drought-tolerant genotypes kept their seed coat intact and minimized the aflatoxin contamination under an intermittent water deficit
Multi-locus genome wide association study uncovers genetics of fresh seed dormancy in groundnut
Get PDFPre-harvest sprouting (PHS) in groundnut leads to substantial yield losses and reduced seed quality, resulting in reduced market value of groundnuts. Breeding cultivars with 14–21 days of fresh seed dormancy (FSD) holds promise for precisely mitigating the yield and quality deterioration. In view of this, six multi-locus genome-wide association study (ML-GWAS) models alongside a single-locus GWAS (SL-GWAS) model were employed on a groundnut mini-core collection using multi season phenotyping and 58 K “Axiom_Arachis” array genotyping data. A total of 9 significant SNP-trait associations (STAs) for FSD were detected on A01, A04, A08, A09, B02, B04, B05, B07 and B09 chromosomes using six ML-GWAS models. Additionally, the SL-GWAS model identified 38 STAs across 14 chromosomes of groundnut. A single STA on chromosome B02 (qFSD-B02-1) was consistently identified in both ML-GWAS and SL-GWAS models. Furthermore, candidate gene mining identified nine high confidence genes viz., Cytochrome P450 705 A, Dormancy/auxin associated family protein, WRKY family transcription factor, Protein kinase superfamily protein, serine/threonine protein phosphatase, myb transcription factor, transcriptional regulator STERILE APETALA-like, ethylene-responsive transcription factor 7-like and F-box protein interaction domain protein as prime regulators involved in Abscisic acid/Gibberellic acid signaling pathways regulating dormancy/germination. In addition, three of the allele-specific markers developed from the identified STAs were validated across a diverse panel. These markers hold potential for increasing dormancy in groundnut through marker-assisted selection (MAS). Thus, this research offers insights into genetic and molecular mechanisms underlying groundnut seed dormancy in addition to providing markers and donors for breeding future varieties with 2–3 weeks of FSD
Research on Moringa (Moringa oleifera Lam.) in Africa
Get PDFWhile Moringa oleifera Lam. is gaining importance in Africa, especially sub-Saharan Africa, it is unclear whether research is following the quick pace of its development on the continent. Therefore, this article analyzes the landscape of research dealing with moringa in Africa. This systematic review draws upon 299 eligible articles identified through a search carried out on the Web of Science in April 2023. Research on M. oleifera is rather recent in Africa but interest is increasing among scholars. While the research field is multidisciplinary and cross-sectoral, the literature seems to focus on biological and environmental sciences. Moreover, research is performed mainly in South Africa, Nigeria, Egypt, and Ghana. The analysis suggests a significant potential contribution of moringa to food security and nutrition, climate change mitigation/adaptation, farming systems resilience, and livelihoods. Its versatility and diverse applications and uses make moringa particularly interesting for developing countries, such as African ones. However, this review also underscores some factors hindering its development. Therefore, there is a need to strengthen research on moringa to unlock its potential in Africa. Investments in research, innovation, and development can help address the many challenges that Africa faces and contribute to the transition towards sustainable and resilient food systems