International Crops Research Institute for the Semi-Arid Tropics
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The impact of water hyacinth biochar on maize growth and soil properties: The influence of pyrolysis temperature
Get PDFIntroduction: Options for managing water hyacinths (WHs) include converting the biomass into biochar for soil amendment. However, less has been known about the impact of WH‐based biochar developed in varying pyrolysis temperatures on plant growth and soil qualities.
Materials and Methods: A pot experiment was undertaken in a factorial combination of WH biochars (WHBs) developed at three temperatures (350°C, 550°C and 750°C) and two application rates (5 and 20 t ha−1), plus a control without biochar. Maize was grown as a test crop for 2 months under natural conditions.
Results: Our study showed that applying WHB developed between 350°C and 750°C at 20 t ha−1 increased maize shoot and root dry biomass by 47.7% to 17.6% and 78.4% to 54.1%, respectively. Nevertheless, raising the biochar pyrolysis temperature decreased maize growth, whereas increasing the application rate displayed a positive effect. The application of WHB generated at 350°C and 550°C at 20 t ha−1 resulted in significant improvements in soil total nitrogen (17.9% to 25%), cation exchange capacity (27.3% to 20.2%), and ammonium‐nitrogen (60.7% to 59.6%), respectively, over the control. Additionally, applying WHB produced from 350°C to 750°C at 20 t ha−1 enhanced soil carbon by 38.5%–56.3%, compared to the control. Conversely, applying biochar
produced at 750°C resulted in higher soil pH (6.3 ± 0.103), electrical conductivity (0.23 ± 0.01 dSm−1) and available phosphorus (21.8 ± 2.53 mg kg−1).
Conclusion: WHBs developed at temperatures of 350°C and 550°C with an application rate of 20 t ha−1 were found to be optimal for growing maize and improving soil characteristics. Our study concludes that pyrolysis temperature significantly governs the effectiveness of biochar produced from a specific biomass source
Identifying phosphorus use efficient genotypes by evaluating a chickpea reference set across different phosphorus regimes
Get PDFLow phosphorus use efficiency (PUE) is one of the abiotic factors that hamper yield and production potential in chickpea (Cicer arietinum L.). Higher yield coupled with improved PUE can make this crop more adaptive and competitive to wide cropland area, especially on marginal soils having low-level phosphorus (P). To identify chickpea germplasm lines that assimilate phosphorus more efficiently under P-deficient soils, 288 diverse genotypes of chickpea belonging to reference set were evaluated for yield component traits and PUE under field conditions for two consecutive years at two phosphorus levels (low P – no phosphorus application and high P – phosphorus application at 40 kg/ha). Based on 2-year evaluation of data under high and low P soil conditions, we identified strong correlations for traits like number of primary and secondary branches, number of pods, biological yield and seed yield indicating that these traits can be used as proxy traits for PUE. ICC 6571 was the best performing genotype under low P conditions while ICC 6579 yielded maximum under high P regime. We report 16 genotypes namely ICC 1052, ICC 1083, ICC 1098, ICC 1161, ICC 2072, ICC 4418, ICC 4567, ICC 4991, ICC 5504, ICC 5639, ICC 7413, ICC 8350, ICC 9590, ICC 9702, ICC 11584 and ICC 13357 as phosphorus use efficient genotypes based on their better performance for yield and yield-contributing traits under low P compared to high P conditions. These genotypes can be exploited in future as potential donors for development of phosphorus use efficient chickpea cultivars
Genome-wide association study reveals marker–trait associations for major agronomic traits in proso millet (Panicum miliaceum L.)
No full textProso millet (Panicum miliaceum L.) is an ancient grain recognized for its excellent water-use efficiency and short growing season. It is an indispensable part of the winter wheat-based dryland cropping system in the High Plains of the USA. Its grains are endowed with high nutritional and health-promoting properties, making it increasingly popular in the global market for healthy grains. There is a dearth of genomic resources in proso millet for developing molecular tools to complement conventional breeding for developing high-yielding varieties. Genome-wide association study (GWAS) is a widely used method to dissect the genetics of complex traits. In this pilot study of the first-ever GWAS in the US proso millet, 71 globally diverse genotypes of 109 the US proso millet core collection were evaluated for five major morpho-agronomic traits at two locations in western Nebraska, and GWAS was conducted to identify single nucleotide polymorphisms (SNPs) associated with these traits. Analysis of variance showed that there was a significant difference among the genotypes, and all five traits were also found to be highly correlated with each other. Sequence reads from genotyping-by-sequencing (GBS) were used to identify 11,147 high-quality bi-allelic SNPs. Population structure analysis with those SNPs showed stratification within the core collection. The GWAS identified twenty marker–trait associations (MTAs) for the five traits. Twenty-nine putative candidate genes associated with the five traits were also identified. These genomic regions can be used to develop genetic markers for marker-assisted selection in proso millet breeding
The auxin efflux carrier PIN1a regulates vascular patterning in cereal roots
Get PDFBarley (Hordeum vulgare) is an important global cereal crop and a model in genetic studies. Despite advances in characterising barley genomic resources, few mutant studies have identified genes controlling root architecture and anatomy, which plays a critical role in capturing soil resources.
Our phenotypic screening of a TILLING mutant collection identified line TM5992 exhibiting a short-root phenotype compared with wild-type (WT) Morex background. Outcrossing TM5992 with barley variety Proctor and subsequent SNP array-based bulk segregant analysis, fine mapped the mutation to a cM scale. Exome sequencing pinpointed a mutation in the candidate gene HvPIN1a, further confirming this by analysing independent mutant alleles.
Detailed analysis of root growth and anatomy in Hvpin1a mutant alleles exhibited a slower growth rate, shorter apical meristem and striking vascular patterning defects compared to WT. Expression and mutant analyses of PIN1 members in the closely related cereal brachypodium (Brachypodium distachyon) revealed that BdPIN1a and BdPIN1b were redundantly expressed in root vascular tissues but only Bdpin1a mutant allele displayed root vascular defects similar to Hvpin1a.
We conclude that barley PIN1 genes have sub-functionalised in cereals, compared to Arabidopsis (Arabidopsis thaliana), where PIN1a sequences control root vascular patterning
Rice Transcriptomics Reveal the Genetic Determinants of An In Planta Photorespiratory Bypass: a Novel Way to Increase Biomass in C3 Plants
No full textDeveloping C4 rice is one of the global research challenges for yield improvement. In the optimal environment, the key difference between C3 and C4 plants with reference to biomass accumulation is photorespiration. Photorespiration is important for a plant’s survival. In spite of the high energy cost and carbon loss, diversion of a significant part of carbon from photorespiration to enrich CO2 concentration (preventing carbon loss) was opted for. Installation of photorespiratory bypasses was reported to improve biomass and yield in C3 plants. The contribution of non-foliar photosynthesis to yield improvement was well documented. However, its underlying genetic differences, when compared to foliar photosynthesis, are a research gap. In three rice genotypes (APO, BAM4234, and CROSSA), we compared the expression levels (for genes associated with photosynthesis and photorespiration) between the photosynthetic non-foliar (3–5-day old developing grains and peduncle) and foliar (flag leaf) organs to understand their differential expression pattern using an RNA-seq approach. Significant downregulation of the genes of photorespiration was observed in non-foliar photosynthetic tissue (3–5 dpa old developing grains) when compared to the flag leaves. Simultaneously, our study also revealed significant upregulation of the chloroplastic pyruvate dehydrogenase (cpPDC, BGIOSGA015796) gene in developing grains, when compared to the flag leaf, in all three genotypes. The occurrence of an in planta photorespiratory bypass in the photosynthetic tissues of the developing grains in rice is proposed. Enhanced expression levels for the cpPdc gene in the foliar tissues will potentially install a photorespiratory bypass for enhanced biomass accumulation and thereby yield
Adaptability and Cultivation of Sorghum Under Climate Change Scenarios
No full textThis chapter thoroughly investigates the vital role of sorghum (Sorghum bicolor) in arid agroecosystems, specifically emphasizing its significance in South Asia and sub-Saharan Africa. It highlights significant challenges in post-rainy sorghum production, attributing them to the complexities of genotype–environment interactions and the limited integration of essential physiological traits into sorghum breeding, further complicated by the absence of sophisticated, breeder-friendly phenotyping tools. To address these challenges, the chapter meticulously characterizes the post-rainy sorghum production areas in India, utilizing advanced modeling tools, revealing distinct production zones and drought stress patterns that impact yields, necessitating optimization strategies. Innovative approaches, like homogeneous system units, are introduced to augment sorghum production through well-planned genotype × management combinations.
The chapter explores the modification of plant water-use traits as a potential solution to balance trade-offs between grain and stover production. It examines component traits crucial for drought adaptation, extending beyond grain yield considerations to factors such as limited transpiration, soil drought, and canopy development. Specific traits, including leaf size, leaf angle, transpiration efficiency, and the stay-green trait, are underscored for their pivotal roles in enhancing crop resilience to water constraints.
The chapter also investigates potential molecular and genetic approaches to fortify sorghum drought adaptation. It concludes by emphasizing the complexity of enhancing drought adaptation in sorghum and advocates for precise phenotyping techniques, illustrated through sensor-based high-throughput phenotyping
Exploring Metabolomics to Innovate Management Approaches for Fall Armyworm (Spodoptera frugiperda [J.E. Smith]) Infestation in Maize (Zea mays L.)
Get PDFThe Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is a highly destructive lepidopteran pest known for its extensive feeding on maize (Zea mays L.) and other crops, resulting in a substantial reduction in crop yields. Understanding the metabolic response of maize to FAW infestation is essential for effective pest management and crop protection. Metabolomics, a powerful analytical tool, provides insights into the dynamic changes in maize’s metabolic profile in response to FAW infestation. This review synthesizes recent advancements in metabolomics research focused on elucidating maize’s metabolic responses to FAW and other lepidopteran pests. It discusses the methodologies used in metabolomics studies and highlights significant findings related to the identification of specific metabolites involved in FAW defense mechanisms. Additionally, it explores the roles of various metabolites, including phytohormones, secondary metabolites, and signaling molecules, in mediating plant–FAW interactions. The review also examines potential applications of metabolomics data in developing innovative strategies for integrated pest management and breeding maize cultivars resistant to FAW by identifying key metabolites and associated metabolic pathways involved in plant–FAW interactions. To ensure global food security and maximize the potential of using metabolomics in enhancing maize resistance to FAW infestation, further research integrating metabolomics with other omics techniques and field studies is necessary
Pearl Millet: Pest Management
No full textThe pest status in pearl millet has been classified either as regular (regular occurrence, economic damage, high loss in grain yield) or occasional (occasional occurrence, sporadic attack with economic damage, high/moderate loss in grain yield). The pest problem has increased with the introduction of high-yielding varieties. Shoot fly, stem borer, white grubs, ear head worms, and gray weevil ( Cyrtepistomuscastaneus ) are the key pests of pearl millet in India and need proper control measures. Other pests, such as grasshoppers, blister beetles, surface grasshoppers, armyworms, and hairy caterpillars, are of secondary importance. During an on-farm survey, shoot fly ( A. approximata ), stem borers ( Chilo partellus, Coniesta ignefusalis; Sesamia inferens ) cotton bollworm ( Helicoverpa armigera ), fall armyworm ( Spodoptera frugiperda ), and gray weevil damaged the crop in India. This chapter discusses the major insect pests of pearl millet, with their economic importance, status, nature of damage, and control measures
Cash transfers and voting among young women in Malawi
No full textWe investigate the effects of cash transfer programs on adolescent females’ likelihood to vote in Malawi using data from a randomized control experiment. We find that cash transfers reduce adolescent females’ likelihood to vote. Our finding is consistent with existing evidence, which indicates an inverse relationship between income and voting in developing democracies. We also find suggestive evidence that cash transfers reduce the likelihood of voting through an income effect. By increasing the income of recipients, cash transfers could reduce the marginal utility of immediate financial gains that individuals might obtain from voting (in the form of vote buying) in developing democracies. In doing so, they might lower the incentive to participate in voting
Breeding for water-logging tolerance in pigeonpea: current status and future prospects
Get PDFPigeonpea is grown in semi-arid tropics where the annual precipitation ranges from 200 to 800 mm and soil orders comprising of Inceptisols, Entisols, Alfisols, Vertisols, Mixed soils, and Aridisols. During monsoons, the semi-arid tropics also receive up to 140–180 mm/day rainfall for a span of 5–10 days, highlighting the chances of waterlogging in an early vegetative stage of pigeonpea, causing 25–30% yield loss in the Indian subcontinent. Waterlogging is a state where soil reaches saturation at submergence, creating an anaerobic condition in the root zone of the plants. As a result, plant withering, leaf chlorosis, stunted growth, lowered photosynthetic rate and plant mortality is evidenced widely. In response to waterlogging, the formation of aerenchyma cells, lenticels and adventitious roots were noticed as morphological adaptations. Whereas, the production of proline, peroxidase, superoxide dismutase, ethylene and alcohol dehydrogenase (ADH) as biochemical modifications. The minimal breeding efforts for waterlogging tolerance in pigeonpea may be the reason for the susceptibility of current varieties to waterlogging stress. This review emphasized the importance of breeding for waterlogging tolerance in pigeonpea. It focused on the morphological, physiological and biochemical adaptations of a plant when subjected to waterlogging stress. It accentuated the need for a standard screening protocol for waterlogging tolerance. Breeding strategies inclusive of novel single pod descent method, marker-assisted selection and rapid generation advancement techniques are discussed in detail