Genetics and Plant Breeding Project Proposal

Project Description – Project Proposal

Starting Point
Objectives and work programme
Project- and subject-related list of publications
Supplementary information on the research context
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Project Proposal

Unveiling the Genetic Blueprint of PUE Traits in European Maize Landraces: A Comprehensive Approach for Customized Breeding Programs

1 Starting Point

State of the art

Introduction: Landraces, shaped by generations of farming, represent a unique repository of biodiversity. Maize, originating in Mexico, has spread globally through diverse landraces. Seed banks house thousands of these landrace varieties, offering untapped genetic diversity (Prasanna, 2010). This resource holds immense potential for plant improvement, enabling adaptation to environmental changes and ensuring sustainable agriculture. The conservation and exploration of landrace diversity emerge as pivotal strategies for enhancing crop resilience and global food security.

European maize landraces, embodying locally adapted and historically significant cultivars, stand as a valuable genetic reservoir for enhancing the efficiency of phosphorus use in Zea mays (Bovill et al., 2013). In light of increasing concerns about phosphorus availability and environmental impact, this research proposal aims to elucidate the genomic underpinnings of phosphorus use efficiency characters in European maize landraces. By employing a comprehensive approach that integrates genomic, transcriptomic, and physiological analyses, this study seeks to identify key genetic markers associated with enhanced PUE. The insights gained from this research will contribute to the emergence of targeted crop breeding programs aimed at enhancing Zea mays cultivars tailored to European agro ecosystems, fostering sustainable phosphorus management, and ensuring food security in the face of evolving agricultural challenges.

Role of Phosphorus in Plant Life: Phosphorus, recognized as the second most crucial element following nitrogen, plays a crucial function in sustaining vitality as well as functionality of crops (Prietzel etal., 2015). Its involvement in key processes such as phosphorylation, dephosphorylation, photosynthesis, ATP production, and redox reactions underscores its significance in plant growth, development, and reproduction. Essential pools of phosphorus in plants include phospho-lipids, DNA, RNA, phosphorylated proteins, and phosphorylated esters (Lambers, 2022). Despite its critical role, phosphorus deficiency poses a significant abiotic stress, limiting crop yield globally. A substantial portion of cropland, particularly in developing countries, is afflicted by phosphorus deficiency, with more than 500 crores hectares of area world-wide considered Phosphorus-deficient (Solangi et al., 2023). The soil solution’s phosphorus concentration falling below 10 µm is deemed critically low for optimal crop yield (Syers et al., 2008). Traditional solutions involve chemical fertilizer applications, but the excessive use has led to ecological and environmental issues. Compounded by the depletion of non-renewable phosphate rock, expected within the next few centuries, the need for sustainable phosphorus management is urgent. This underscores the need to find genotypes with high Phosphorus-Use Efficiency, the yield produced per unit of available phosphorus in the soil surface, utilizing molecular breeding methods grounded in genetic analysis (Li et al., 2019). The pursuit of such sustainable solutions is crucial for addressing global phosphorus challenges and ensuring agricultural productivity in the face of depleting resources.

Preliminary works

Phosphorus Use Efficiency (PUE) in Plants: Molecular and Physiological Dimensions

Phosphorus Use Efficiency (PUE) emerges as a crucial trait in plants, essential for achieving optimal biomass and yield, particularly under low-phosphorus conditions. The intricate process of P absorption is influenced by a myriad of factors, encompassing soil chemistry, physical properties, root-soil interactions, and microbial associations (Pierret et al., 2007). Phosphorus-Use Efficiency is the ratio of yield of grain or biomass to the supplied phosphorus in a low-phosphorus environment, consists of two vital components: Phosphorus Uptake-Efficiency and Phosphorus Utilization-Efficiency (Weiß et al., 2022). Phosphorus Utilization Efficiency indicates a crop’s capacity to absorb phosphorus from the top soil, stands out as a crucial factor influencing PUE, playing a significant role in the variation of maize hybrid yields within a recombinant inbred lines (RIL) population under low-phosphorus stress. The strategic enhancement of PupE becomes imperative for overall PUE improvement. Root architecture adjustments, exudation of P-mobilizing organic acids, and the involvement of specific genes, such as Pup1-specific protein kinase, contribute to heightened P uptake in P-efficient plants (Reddy et al., 2020). Regulation of hormones ( gibberellic acid, ethylene, auxin, and abscisic acid), plays a vital role in influencing root morphology and enhancing the release of organic acids and enzymes, ultimately facilitating improved P acquisition (Khan et al., 2023). Physiological changes due to the deficiency phosphorus consist of the release of several compounds including organic acids, H⁺, and biological enzymes, along with alterations in root architecture. While biomass and yield serve as crucial selection criteria for screening P-efficient germplasm, their complexity underscores the importance of a comprehensive understanding of the underlying quantitative genetic control. The unravelling of intricate molecular and physiological mechanisms associated with PUE provides valuable insights essential for steering sustainable crop production in P-limiting environments (Mehra et al., 2015).

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Molecular Dynamics of Maize under Low-Phosphate ConditionsTop of Form When confronted with insufficient phosphate (P) levels, plants like maize employ a sophisticated phosphate starvation response to improve the absorption, utilization, and recycling of phosphorus, ensuring sustained growth and development (Calderón et al., 2011). This adaptive process involves complex changes in transcription, genome, and metabolism based regulatory processes. Identification of 5 Pht1 genes within maize has highlighted their crucial part in the

absorption and allocation of phosphate between the top soil and shoot (Nagy et al., 2006). Through RNA sequencing of Qi319 and 99038 under both optimal and low-P conditions, scientists uncovered 7 new and known families of miRNA, with the miRNA399-ZmPHO2 pathway identified as pivotal in regulating P uptake (Pei et al., 2013). Additionally, the interaction between LncRNA1 and miRNA399 was found to enhance the adaptation of crops to lower P conditions (Du et al., 2018). An examination of the root protein of Qi379 and protein mutant 99038 revealed differential expression of proteins associated with cellular as well as metabolic teps, particularly in metabolism of carbon and cell multiplication (Li et al., 2008). Further analysis of the phosphoproteome and proteome of Qi319 roots exposed to low-P treatment indicated significant changes in phosphoproteins related to metabolic and cellular pathways, affecting carbon flux in metabolic processes (Li et al., 2014). The study extended to investigating the metabolite-level response to P starvation in two maize lines, HM-4 (P-sensitive) and PEHM-2 (P-tolerant). The findings revealed a high level in the accumulation of di-saccharides and tri-saccharides, coupled with changes in secondary metabolites related to metabolism of ammonium, especially in leaves. In contrast, metabolites containing phosphate and organic acids decreased, while specific amino acids (glutamine, asparagine, and serine) increased in shoot and root tissues. This comprehensive analysis provides valuable insights into the intricate molecular responses of maize to low-P conditions, contributing to our understanding of plant adaptation strategies in nutrient-deficient environments (Li et al., 2019).

Genomic Basis of Phosphorus Use Efficiency Traits in Response to Starvation: Insights from a QTL Perspective: The exploration of quantitative trait loci (QTLs) linked to phosphorus-use efficiency (PUE) traits under phosphorus starvation has been extensively conducted in various crop plants, offering valuable insights into the genetic foundations of plants’ adaptive responses to nutrient stress (Khan et al., 2023). Research in wheat, rice, corn, common beans, and soybean has pinpointed crucial genomic regions that influence PUE, contributing to a good knowledge of the molecular processes governing plant reactions to phosphorus scarcity. Traditional mapping of linkage, involving two parental populations of mapping derived from controlled type crosses, has been a primary method for identifying QTLs (Dash & Mishra, 2024). However, this method presents limitations, particularly in detecting QTLs with small effects, necessitating large population sizes. The inherent constraints of bi-parental mapping, such as limited genome shuffling across generations and the localization of QTLs to broad chromosomal regions (10 to 20 cM), emphasize the need for alternative strategies to comprehensively understand the genetic architecture of PUE traits (Lucas, 2014). Emerging technologies and advanced mapping approaches are poised to address these challenges, providing a more nuanced understanding of the intricate genetic factors governing plants’ ability to efficiently utilize phosphorus under stressful conditions (Cembrowska-Lech et al., 2023).

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Unlocking Precision in QTL Mapping: The Potential of Association Mapping and Genotyping by Sequencing: Association mapping has raised as a potent approach for conducting genome wide association studies (GWAS), allowing for the selection of molecular markers associated with specific traits (Ibrahim et al., 2020). By leveraging a diverse panel of genotypes, AM capitalizes on natural populations with extensive recombination over numerous generations, offering a finer resolution compared to traditional genetic mapping methods. The key advantage lies in exploiting the linkage disequilibrium between markers and polymorphisms in the panel to pinpoint quantitative trait loci (QTLs) (Álvarez et al., 2014). In recent years, GWAS has evolved into a robust tool utilizing 100s of markers across all chromosomes to unveil genetic difference linked to specific traits. The synergy between GWAS and high throughput next generation sequencing techniques positions AM as the optimal technique for QTLM in crops. Genotyping by sequencing (GBS) is robust and cost-effective approach, that emerged as a standout tool in this context (Zuluaga et al., 2021). GBS facilitates the discovery and genotyping of markers, proving highly effective in developing GL maps, conducting GWAS, and FM or MBC of QTLs in various plants. Its successful applications in crops like soybean and chickpea underscore the versatility and potential of GBS in advancing our knowledge of the genetic makeup underlying multiple characters in plants (Yadava et al., 2023).

SNP Markers: Pioneering Precision in Phosphorus Use Efficiency across Diverse Crops

Single-nucleotide polymorphism markers have become essential in domain of MAS (marker-assisted selection), owing to their relative occurrence, particular locus, co-dominant inheritance, and the effectiveness of high throughput genotype protocol (Terakami et al., 2011). The significance of SNP markers is underscored by their relation to phosphorus-use efficiency (PUE) linked characters across a spectrum of crops. Prominent studies have identified significant single-nucleotide polymorphisms (SNPs) linked with Phosphorus-Use Efficiency (PUE) in maize (Wang et al., 2019), soybean (Ning et al., 2016), and rice (Wissuwa et al., 2015). This collective body of research highlights the versatility of SNP markers in deciphering the genetic underpinnings of PUE across diverse plant species. As these markers continue to play a pivotal role in crop improvement strategies, their application in MAS holds great promise for enhancing the efficiency and precision of breeding programs geared towards developing crops with superior phosphorus utilization capabilities.

1 Objective and work programs

1.1 Total duration

Three years

1.2 Objectives

Main aim of this project is to unlock untapped genetic potential for phosphorus-use-efficiency (PUE) in European maize landraces predating the era of intensive phosphorus fertilizer application. By employing a multidimensional approach, this study aims to:

Conduct Elaborate Field Trials: Investigate the response of diverse European maize landraces to varying phosphorus levels through extensive field trials. This will involve

systematically characterizing PUE across multiple genotypes under different phosphorus regimes, providing a foundation for subsequent trait analysis.
Identify Relevant Traits and Measurement Protocols: Determine the key physiological and morphological traits associated with PUE response in maize landraces. Employ advanced phenotyping techniques to quantify these traits accurately, considering parameters such as root architecture, nutrient uptake effectiveness, accumulation of biomass, and yield parameters.
Unraveling the Genetic Foundation of PUE: Employ cutting-edge genomic tools to find the genetic makeup of Phosphorus Use Efficiency (PUE) traits in European maize landraces. Utilize state-of-the-art techniques such as genome wide association studies and molecular markers to pinpoint loci and candidate genes linked to improve PUE. The integration of genomic and phenotypic data will facilitate the construction of a comprehensive genetic map for PUE traits.
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Facilitate Targeted Breeding Programs: Synthesize the gained knowledge to formulate targeted breeding strategies for improving PUE in modern maize varieties. Develop molecular markers linked to favorable alleles for PUE traits, enabling efficient marker-assisted selection (MAS) in breeding programs. Provide breeders with valuable insights into selecting superior maize genotypes with enhanced PUE for sustainable phosphorus management in agriculture.

Research questions

How do diverse European maize landraces respond to varying phosphorus levels, and what is the extent of phosphorus-use-efficiency (PUE) across multiple genotypes under different phosphorus regimes?
What are the key physiological and morphological traits associated with PUE response in maize landraces, and how can advanced phenotyping techniques be employed to accurately quantify these traits, considering parameters such as root architecture, nutrient uptake efficiency, biomass accumulation, and yield components?
What is the genetic blueprint of PUE characteristics in European maize landraces, and how can state-of-the-art genomic tools, including genome wide association studies and advanced molecular markers, be utilized to identify specific loci and candidate genes associated with enhanced PUE?
How can the integration of genomic and phenotypic data contribute to the development of a comprehensive genetic map for PUE traits in European maize landraces?
In what ways can the acquired knowledge be integrated to devise specific breeding strategies aimed at improving the efficiency of phosphorus Use in contemporary maize varieties?
In what ways can the findings provide valuable insights to breeders for selecting superior maize genotypes with enhanced PUE, addressing the challenges of phosphorus scarcity and environmental sustainability in agriculture?

This study is significant because it investigates genetic determinants impacting phosphorus-use-efficiency (PUE) in European maize landraces, giving a comprehensive strategy for targeted breeding programs. The work tackles the worldwide dilemma of phosphorus depletion in agriculture by merging genomic, transcriptomic, and physiological investigations. The discovery of genetic markers linked to increased PUE in maize has the potential to revolutionize sustainable phosphorus management, reduce environmental impact, and secure food security, making a substantial contribution to global agricultural practices.

1.3 Work program and proposed research methods

Experimental Design and Methodology: The research will be conducted in multiple phases, encompassing field trials, phenotypic characterization, genomic analyses, and targeted breeding efforts. The experimental design is structured to systematically address each aspect of the study.

Field Trials:

a. Experimental Site: The designated study site is situated in Heidfeldhof. Within the course of the growing seasons, the research panel will sow a carefully chosen set of 20 maize accessions under conditions of low phosphorus (P), normal phosphorus (P), and high phosphorus (P).

Soil Characteristics Recording: To comprehensively characterize the physicochemical properties of the soil in the rhizosphere (0–20 cm depth) at the two locations throughout the growing period, climatic data and soil samples will be collected. The measured soil parameters include sand, silt, clay, apparent density, pH (H2O), macro and micro elements, soil organic matter, cation exchange capacity, exchangeable aluminum, available phosphorus, low phosphorus, and high phosphorus. It is noteworthy that phosphorus concentration is identified as the primary limiting factor, while all other management practices will remain consistent.

b. Experimental Layout: The experimental design will utilize an augmented α-design, with each treatment replicated three times. Within each replicate, there should be sufficient (14-16) blocks, and each block comprised (20-25) plots. Genotypes were individually planted in rows measuring 1.5 meters in length, with a plant spacing of 0.25 meters and a row spacing of ½ meters. Phenotypic measurements were carried out on four plants positioned in the center of each plot, following the methodology outlined by Bayuelo and Ochoa in 2014.

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c. Phosphorus Treatments: Experiments were carried out in soils deprived of phosphorus (P), given that no fertilizers had been applied in the four preceding growing seasons. The treatments included low-P, normal or optimum-P, and high-P, with application rates of 23 kg P₂O₅per ha, 60 kg P₂O₅per ha, and 97 kg P₂O₅ per ha, respectively. These phosphorus treatments were applied as calcium superphosphate during planting. Additionally, all plots received supplemental nitrogen (N) at a rate of 60 kg N per ha as urea at planting and an additional 60 kg N per ha at the silking stage.

Weed control was implemented through manual weeding and the application of bromoxynil at a rate of 1 Litre per ha, administered 20 days after emergence. The plants were nurtured until reaching maturity and were subsequently harvested, following the approach outlined by Bayuelo-Jiménez and Ochoa-Cadavid in 2014.

d. Genotype Selection: This study will utilize a varied assortment of European maize landraces (Zea mays L. ssp. mays) that existed before the widespread adoption of phosphorus fertilizers. A meticulous selection process will be undertaken to curate a panel comprising 20 to 30 maize landraces, considering factors such as historical records, genetic diversity, geographic origin, and morphological characteristics. These attributes encompass differences in crop yield, reactions to phosphorus fertilization, vulnerability to stalk lodging, and the type of grain, spanning from floury to flint corn.

To ensure the authenticity and purity of the selected landraces, seeds will be sourced from reputable Gene banks, specifically The Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), as well as collaborating researchers. Rigorous measures, including genetic testing and visual inspection, will be implemented to guarantee the purity and authenticity of the acquired seeds.

To minimize initial variations arising due to seed age differences and indigenous seed phosphorus concentration, all chosen genotypes will undergo rejuvenation under uniform conditions. This uniform treatment aims to create a consistent starting point for the experimental material.

Trait Identification and Measurement Protocols: The study will encompass an array of traits for comprehensive analysis, including:
Yield and Biomass-linked characters:

Yield per plant

Shoot dry weight per plant

All dry weight per plant

PUE-Related Traits in Seed and Shoot:

P concentration in shoot, seed and root

Seed, Root and shoot P concentration per plant

All P content per plant

Seed, Root and shoot P utilization efficiency

All P utilization efficiency

Phenotyping for evaluating Phosphorous Use Efficiency Trait

Before severing shoots from roots at the crown, measurements were taken for plant height, tiller number, and root length. Root traits will assess using a root scanner with WinRhizo software. Manual determination of root length (RL) was performed using a meter scale. Chlorophyll concentration (CHL) will measure using the MC-100 chlorophyll concentration meter. Total leaf area (TLA) will be measured using a leaf area meter.

The cleaned root and shoot components will dry for 48 hours at 65 °C to calculate shoot dry weight (SDW, g per plant), root dry weight (RDW), total dry weight (TDW), and the root-to-shoot ratio. All measurements should be replicated three times to ensure accuracy and reliability.

Broad-sense heritability will calculate as defined by Reddy et al., 2020.

Genomic Analyses:

This aims to dissect the genomics behind the efficiency of Phosphorus-Use in European maize landraces. The investigation involves unraveling the genetic architecture associated with PUE through the application of cutting-edge genomic tools. The methodology includes conducting genome-wide association studies (GWAS), utilizing advanced molecular markers, and integrating genomic and phenotypic data. The ultimate goal is to develop a comprehensive genetic map that delineates the genetic factors influencing PUE traits in European maize landraces.

DNA Extraction and Sequencing:

DNA Extraction: Collect young leaves from randomly selected maize landrace samples. Employ a DNA extraction method, CTAB (cetyltrimethylammonium bromide) and perform extraction under controlled conditions to prevent contamination and degradation. Ensure the purity and integrity of extracted DNA using spectrophotometry

Whole-Genome Sequencing (WGS) to capture the entire genomic landscape: Prepare high-quality DNA samples for library construction and utilize next-generation sequencing platforms, Illumina for WGS. Sequence samples to sufficient depth for robust variant calling and genomic analysis. Consider paired-end sequencing for improved accuracy.

Implement quality control measures at each step, including assessing DNA concentration, purity, and fragment size.

Monitor sequencing run metrics to ensure data quality and reliability.

Quality Control and Pre-processing:

To ensure the quality and accuracy of sequencing data for reliable analysis, below steps are considered.

Implement stringent quality control measures to filter out low-quality sequencing reads.
Precise genomic mapping relies on aligning reads of high quality to the maize reference genes.
Conduct Genome-Wide Association Studies (GWAS) to pinpoint gene loci correlated to Phosphorus-Use-Efficiency (PUE) traits.
Phenotypic Data Integration: Combine phenotypic data obtained from advanced phenotyping techniques with genomic data.
Perform Population Structure Analysis by conducting Principal Component Analysis (PCA) and kinship analysis to address population structure and assess relatedness.
GWAS Implementation: Utilize statistical models to identify gene loci linked with trait, Phosphorus-Use-Efficiency.
Correction for Multiple Testing: Apply appropriate correction methods to control false positives in GWAS results.
Identification of Candidate Genes and Loci:
Functional Annotation: Annotate significant gene loci to identify candidate genes linked with enhanced PUE.
Pathway Analysis: Conduct pathway analysis to understand the biological pathways related to phosphorus metabolism and nutrient utilization.
Advanced Molecular Marker Development for efficient selection of PUE traits.
Single Nucleotide Polymorphism (SNP) Analysis: Detect single-nucleotide polymorphisms that are linked with character Phosphorus-Use-Efficiency.
High-Throughput Genotyping: Utilize high-throughput genotyping technologies SNP arrays for large-scale marker development.
Validation: Validate developed markers in an independent set of maize landrace samples to ensure accuracy.

Targeted Breeding Programs: Facilitate targeted breeding programs to enhance efficiency of phosphorus use in maize.
Synthesize knowledge to formulate targeted breeding strategies for improving PUE:

Insights gained from the research utilized to design targeted breeding strategies for enhancing PUE in contemporary maize varieties.

Data Integration: Combine results from field trials, advanced phenotyping, and genomic studies to understand the complex interactions influencing PUE.
Identification of Key Traits: Identify the most crucial physiological and molecular traits associated with enhanced PUE in maize landraces.
Trait Combinations: Explore trait combinations that contribute synergistically to improved PUE.
Environmental Adaptability: Consider environmental adaptability of identified traits to ensure broad applicability across diverse agro ecosystems.
Breeding Objectives: Define clear breeding objectives for enhancing PUE, considering both yield and resource-use efficiency.

Considerations: Prioritize traits with a significant impact on PUE. Account for interactions between genetic and environmental factors.

Marker Development: Develop molecular tools to facilitate the selection of maize varieties with superior PUE traits.

Steps include:

Candidate Gene Identification: Use genomic data to identify candidate genes associated with enhanced PUE.
SNP Discovery: Identify single nucleotide polymorphisms (SNPs) within or near candidate genes.
Molecular Marker Development: Design molecular marker, SNP markers linked to favourable alleles for target traits.
Validation: Validate developed markers in diverse maize varieties to ensure their association with enhanced PUE.

Considerations: Ensure the specificity and reliability of molecular markers. Collaborate with molecular biologists and geneticists for marker development.

List of publications

Álvarez, M. F., Mosquera, T., & Blair, M. W. (2014). The use of association genetics approaches in plant breeding. Plant Breeding Reviews: Volume 38, 17-68.

Bayuelo-Jiménez, J. S., & Ochoa-Cadavid, I. (2014). Phosphorus acquisition and internal utilization efficiency among maize landraces from the central Mexican highlands. Field Crops Research, 156, 123-134.

Bovill, W. D., Huang, C. Y., & McDonald, G. K. (2013). Genetic approaches to enhancing phosphorus-use efficiency (PUE) in crops: challenges and directions. Crop and Pasture Science, 64(3), 179-198.

Calderón-Vázquez, C., Sawers, R. J., & Herrera-Estrella, L. (2011). Phosphate deprivation in maize: genetics and genomics. Plant physiology, 156(3), 1067-1077.

Cembrowska-Lech, D., Krzemińska, A., Miller, T., Nowakowska, A., Adamski, C., Radaczyńska, M., & Mikiciuk, M. (2023). An Integrated Multi-Omics and Artificial Intelligence Framework for Advance Plant Phenotyping in Horticulture. Biology, 12(10), 1298.

Dash, M., & Mishra, A. (2024). QTL Mapping: Principle, Approaches, and Applications in Crop Improvement. Smart Breeding, 31.

Du, Q., Wang, K., Zou, C., Xu, C., & Li, W. X. (2018). The PILNCR1-miR399 regulatory module is important for low phosphate tolerance in maize. Plant Physiology, 177(4), 1743-1753.

Ibrahim, A. K., Zhang, L., Niyitanga, S., Afzal, M. Z., Xu, Y., Zhang, L., & Qi, J. (2020). Principles and approaches of association mapping in plant breeding. Tropical Plant Biology, 13, 212-224.

Khan, F., Siddique, A. B., Shabala, S., Zhou, M., & Zhao, C. (2023). Phosphorus plays key roles in regulating plants’ physiological responses to abiotic stresses. Plants, 12(15), 2861.

Lambers, H. (2022). Phosphorus acquisition and utilization in plants. Annual Review of Plant Biology, 73, 17-42.

Li, D., Wang, M., Kuang, X., & Liu, W. (2019). Genetic study and molecular breeding for high phosphorus use efficiency in maize. Front. Agric. Sci. Eng, 6, 366-379.

Li, K., Xu, C., Fan, W., Zhang, H., Hou, J., Yang, A., & Zhang, K. (2014). Phosphoproteome and proteome analyses reveal low-phosphate mediated plasticity of root developmental and metabolic regulation in maize (Zea mays L.). Plant physiology and biochemistry, 83, 232-242.

Li, K., Xu, C., Li, Z., Zhang, K., Yang, A., & Zhang, J. (2008). Comparative proteome analyses of phosphorus responses in maize (Zea mays L.) roots of wild‐type and a low‐P‐tolerant mutant reveal root characteristics associated with phosphorus efficiency. The Plant Journal, 55(6), 927-939.

Lucas, M. R. (2014). Using Genomic Resources to Breed Cowpeas With Larger Seeds. University of California, Riverside.

Ludewig U., Yuan L.X., (2019). Neumann G. Improving the Efficiency and Effectiveness of Global Phosphorus Use: Focus on Root and Rhizosphere Levels in the Agronomic System. Front. Agric. Sci. Eng.; 6:357–365. doi: 10.15302/J-FASE-2019275.

Mehra, P., Pandey, B. K., & Giri, J. (2015). Genome-wide DNA polymorphisms in low phosphate tolerant and sensitive rice genotypes. Scientific reports, 5(1), 13090.

Nagy, R., Vasconcelos, M. J. V., Zhao, S., McElver, J., Bruce, W., Amrhein, N., … & Bucher, M. (2006). Differential regulation of five Pht1 phosphate transporters from maize (Zea mays L.). Plant Biology, 8(02), 186-197.

Ning, L., Kan, G., Du, W., Guo, S., Wang, Q., Zhang, G., & Yu, D. (2016). Association analysis for detecting significant single nucleotide polymorphisms for phosphorus-deficiency tolerance at the seedling stage in soybean [Glycine max (L) Merr.]. Breeding Science, 66(2), 191-203.

Pei, L., Jin, Z., Li, K., Yin, H., Wang, J., & Yang, A. (2013). Identification and comparative analysis of low phosphate tolerance-associated microRNAs in two maize genotypes. Plant physiology and biochemistry, 70, 221-234.

Pierret, A., Doussan, C., Capowiez, Y., Bastardie, F., & Pagès, L. (2007). Root functional architecture: a framework for modeling the interplay between roots and soil. Vadose Zone Journal, 6(2), 269-281.

Prasanna, B. M. (2010). Phenotypic and molecular diversity of maize landraces: characterization and utilization. Indian Journal of Genetics and Plant Breeding, 70(04), 315-327.

Prietzel, J., Christophel, D., Traub, C., Kolb, E., & Schubert, A. (2015). Regional and site-related patterns of soil nitrogen, phosphorus, and potassium stocks and Norway spruce nutrition in mountain forests of the Bavarian Alps. Plant and soil, 386, 151-169.

Reddy, V. R. P., Das, S., Dikshit, H. K., Mishra, G. P., Aski, M., Meena, S. K., & Sharma, T. R. (2020). Genome-wide association analysis for phosphorus use efficiency traits in mungbean (Vigna radiata L. Wilczek) using genotyping by sequencing approach. Frontiers in plant science, 11, 537766.

Solangi, F., Zhu, X., Khan, S., Rais, N., Majeed, A., Sabir, M. A., & Kayabasi, E. T. (2023). The Global Dilemma of Soil Legacy Phosphorus and Its Improvement Strategies under Recent Changes in Agro-Ecosystem Sustainability. ACS omega, 8(26), 23271-23282.

Syers, J. K., Johnston, A. E., & Curtin, D. (2008). Efficiency of soil and fertilizer phosphorus use. FAO Fertilizer and plant nutrition bulletin, 18(108), 5-50.

Terakami, S., Nishitani, C., Kunihisa, M., Shirasawa, K., Sato, S., Tabata, S., & Yamamoto, T. (2014). Transcriptome-based single nucleotide polymorphism markers for genome mapping in Japanese pear (Pyrus pyrifolia Nakai). Tree genetics & genomes, 10, 853-863.

Summary

The research proposal seeks to tackle worldwide apprehensions about phosphorus scarcity and its repercussions on crop yield. This objective will be accomplished by investigating the genetic makeup of phosphorus-use-efficiency (PUE) traits in European maize landraces. Recognizing phosphorus as a vital macronutrient, the study seeks to unravel the complex molecular dynamics of maize under low-phosphate conditions, involving intricate changes in transcriptional, genomic, and metabolic networks. The research spans three years and employs a multidimensional approach, including field trials, advanced phenotyping, and cutting-edge genomic analyses. The objectives encompass identifying key physiological traits, conducting genome-wide association studies, and formulating targeted breeding programs for enhancing PUE in maize varieties. The ultimate goal is to contribute to sustainable phosphorus management in agriculture, offering valuable insights to breeders and providing practical tools for developing resilient maize genotypes capable of thriving under varying phosphorus conditions.