Maize Landraces Research Articles

Evaluation of functional plant growth-promoting activities of culturable rhizobacteria associated to tunicate maize (Zea mays var. tunicata A. St. Hil), a Mexican exotic landrace grown in traditional agroecosystems.

Tunicate maize (Zea mays var. tunicata A. St. Hil) is a landrace that constitutes a fundamental aspect of the socio-cultural identity of Ixtenco, Tlaxcala (Mexico) and represents an exotic phenotype whose kernels are enclosed in leaflike glumes. Despite multiple studies conducted worldwide on plant growth-promoting-rhizobacteria (PGPR) in commercial maize varieties grown under monoculture systems, very little is known about bacteria inhabiting native maize landraces in agroecosystems, but for tunicate maize such knowledge is non-existent. This research described and profiled functional groups of culturable rhizobacteria from tunicate maize at two phenological stages (tasseling and maturity/senescence) in a polyculture system, highlighting potential PGPR for biotechnological purposes. Ninety-five rhizobacteria were isolated and molecularly identified, and their physiological activities such as plant growth promotion, production of exogenous lytic enzymes, and antagonism against fungal pathogens were determined. The culturable rhizobacterial community associated to tunicate maize comprised 42 genera, dominated by Bacillaceae, Comamonadaceae, Microbacteriaceae, Micrococcaceae, Oxalobacteraceae, Pseudomonadaceae, and Rhizobaceae families. At tasseling stage, the identified bacteria corresponded to Arthrobacter, Priestia, Herbaspirillum, Pseudomonas, and Rhizobium, and exhibited redundant capabilities for stimulating plant growth and nutrition, and inhibiting fungal phytopathogens. At maturity/senescence stage, the main genera Arthrobacter and Microbacterium displayed lytic capabilities to support mineralization process. We recorded potential novel rhizosphere functional bacteria such as Rhizobium, Sphingobium, and Arthrobacter which are not previously described associated to maize landraces, as well as their bioprospection as PGPR detected at plant phenological stages poorly explored (like maturity/senescence). This taxonomic and functional diversity was attributed to the application of agricultural practices as well as the rhizosphere effect during specific phenological stages. Results described the diversity and functionality of culturable rhizosphere bacteria from tunicate maize in polyculture systems that allowed us the detection of potential rhizobacteria for further developing of biofertilizers and biocontrollers directed as biotechnology for sustainable agriculture, and for generating strategies for conservation of native plants and their microbial genetic resources.

Growth, chlorophyll fluorescence, and gas exchange of three maize landraces in southeastern Mexico

Background: Maize landraces show remarkable diversity and environmental adaptability in Mexico. Nevertheless, few studies have explored physiological mechanisms used by different maize landraces to grow and yield in a particular agroecological region. Question: How do three landrace maize populations from contrasting maize races in southeastern Mexico, differ in their responses in terms of growth, chlorophyll fluorescence, and gas exchange? Studied species: Zea mays L. Study site and date: Yucatan, Mexico; 2017. Methods: The field experiment followed a complete randomized block design, with six replicates. Three contrasting maize landraces were evaluated as treatments. Response variables were vegetative traits, dry matter allocation, yield components, and maize physiological responses. Data were analyzed by one-way ANOVA and post hoc Tukey multiple comparison test (P ≤ 0.05). Results: Maize landraces showed differences in cycle length, plant morphology, and yield performance. The long cycle maize landrace Xnuc-naal, had tall plants that accumulated 17 and 21 % more dry matter than Xmejen-naal and Elotillo, respectively. The short-cycle maize landraces Elotillo and Xmejen-naal exhibit superior physiological responses leading to higher grain yields compared to the Xnuc-naal. Conclusions: The landrace Xnuc-naal stood out for its ability in forage production, whereas Elotillo and Xmejen-naal exhibited notable physiological efficiency in grain production in southeastern Mexico.

Genomic Insights into Pseudomonas protegens E1BL2 from Giant Jala Maize: A Novel Bioresource for Sustainable Agriculture and Efficient Management of Fungal Phytopathogens.

The relationships between plants and bacteria are essential in agroecosystems and bioinoculant development. The leaf endophytic Pseudomonas protegens E1BL2 was previously isolated from giant Jala maize, which is a native Zea mays landrace of Nayarit, Mexico. Using different Mexican maize landraces, this work evaluated the strain's plant growth promotion and biocontrol against eight phytopathogenic fungi in vitro and greenhouse conditions. Also, a plant field trial was conducted on irrigated fields using the hybrid maize Supremo. The grain productivity in this assay increased compared with the control treatment. The genome analysis of P. protegens E1BL2 showed putative genes involved in metabolite synthesis that facilitated its beneficial roles in plant health and environmental adaptation (bdhA, acoR, trpE, speE, potA); siderophores (ptaA, pchC); and extracellular enzymes relevant for PGPB mechanisms (cel3, chi14), protection against oxidative stress (hscA, htpG), nitrogen metabolism (nirD, nit1, hmpA), inductors of plant-induced systemic resistance (ISR) (flaA, flaG, rffA, rfaP), fungal biocontrol (phlD, prtD, prnD, hcnA-1), pest control (vgrG-1, higB-2, aprE, pslA, ppkA), and the establishment of plant-bacteria symbiosis (pgaA, pgaB, pgaC, exbD). Our findings suggest that P. protegens E1BL2 significantly promotes maize growth and offers biocontrol benefits, which highlights its potential as a bioinoculant.

Determination of the Best Performing Sri Lankan Maize Landraces Based on the Kernel Nutritional Composition

Maize (Zea mays L.) is one of the most widely cultivated cereal crops in the world as well as in Sri Lanka. Data on the nutritional composition of maize is beneficial for the food and feed industry, but there is a lack of information regarding this avenue in Sri Lanka. Therefore, this study aimed to investigate the suitable landraces with higher nutritional composition among the different landraces by evaluating nutritional parameters using the rank summation index. The maize kernels derived from 42 local landraces were used and the responses were with varieties Bhadra (Control) and Pacific. The proximate composition was analyzed using Near-infrared spectroscopy (NIR) and carbohydrate content and energy were determined using the calculation method. Subsequently, the data were analyzed by performing ANOVA and the rank summation index (RSI) to identify the best performer among the landraces. The results revealed that there were significant differences (p<0.05) among the nutritional components for moisture, ash, fiber, fat, protein, carbohydrates, and energy among the tested landraces. Accordingly, the maize landraces SEU 22, SEU 31, and SEU 2 were identified as the superior germplasms regarding nutritional composition compared with Bhadra, as they exhibited the lowest RSI of 85, 88, and 89, respectively. Therefore, these maize landraces were recommended for future breeding programs for the development of nutritionally enriched maize grains and for sustainable production where land limitation is a challenge.

Smallholder farmers’ diverse values in maize landrace conservation: A case study from Chiapas, Mexico

Conservation of maize landraces in the Mexico center of origin is critical for sustainable agriculture. However, farmers in many regions of Mexico are reducing landraces for more modern maize varieties, particularly hybrid maize. The reasons why farmers choose to maintain maize landraces have been recently recognized to be strongly linked to their specific values (i.e., intrinsic, instrumental, and relational values). However, there is a lack of studies that empirically investigate the nuances of farmers' specific values and how these values are adequately considered in broad agricultural policies. Using a mixed-methods case study based in indigenous and mestizo communities in Chiapas, Mexico, we analyzed farmers' maize production strategies, how those strategies connect to farmers’ value orientations, and the limitations that they confront in enacting such values. We found that households within both indigenous and mestizo communities fell into one of three categories regarding their maize production: 1) hybrid maize production for market sales, 2) landrace production for household consumption, and 3) a combination of these two strategies. All farmers hold a diversity of values in which mostly instrumental and relational values were mentioned among the three groups of farmers, who emphasized the livelihood and subsistence value of maize. Value differences for farmers who prioritize the cultivation of maize landraces were related to the strength of relational values, such as the biocultural diversity and heritage value of maize. In contrast, the farmers relying on hybrid varieties were the ones confronting the most limitations to their maize production, particularly economic limitations. Based on our empirical findings, we conclude that policies aimed at promoting the conservation of landraces must extend beyond a purely economic and market-oriented approach. The current policy emphasis on instrumental values is likely to fall short in achieving the desired outcomes since it does not sufficiently foster plural values that underpin the continued production of maize landraces.

Regional diversity and leaf microbiome interactions of the fungal maize pathogen Exserohilum turcicum in Switzerland: A metagenomic analysis.

The spread and adaptation of fungal plant pathogens in agroecosystems are facilitated by environmental homogeneity. Metagenomic sequencing of infected tissues allowed us to monitor eco-evolutionary dynamics and interactions between host, pathogen and plant microbiome. Exserohilum turcicum, the causal agent of northern corn leaf blight (NCLB) in maize, is distributed in multiple clonal lineages throughout Europe. To characterize regional pathogen diversity, we conducted metagenomic DNA sequencing on 241 infected leaf samples from the highly susceptible Swiss maize landrace Rheintaler Ribelmais, collected over 3 years (2016-2018) from an average of 14 agricultural farms within the Swiss Rhine Valley. All major European clonal lineages of E. turcicum were identified. Lineages differ by their mating types which indicates potential for sexual recombination and rapid evolution of new pathogen strains, although we found no evidence of recent recombination. The associated eukaryotic and prokaryotic leaf microbiome exhibited variation in taxonomic diversity between years and locations and is likely influenced by local weather conditions. A network analysis revealed distinct clusters of eukaryotic and prokaryotic taxa that correlates with the frequency of E. turcicum sequencing reads, suggesting causal interactions. Notably, the yeast genus Metschnikowia exhibited a strongly negative association with E. turcicum, supporting its known potential as biological control agent against fungal pathogens. Our findings show that metagenomic sequencing is a useful tool for analysing the role of environmental factors and potential pathogen-microbiome interactions in shaping pathogen dynamics and evolution, suggesting their potential for effective pathogen management strategies.

Consistent prokaryotic community patterns along the radial root axis of two Zea mays L. landraces across two distinct field locations.

The close interconnection of plants with rhizosphere- and root-associated microorganisms is well recognized, and high expectations are raised for considering their symbioses in the breeding of future crop varieties. However, it is unclear how consistently plant-mediated selection, a potential target in crop breeding, influences microbiome members compared to selection imposed by the agricultural environment. Landraces may have traits shaping their microbiome, which were lost during the breeding of modern varieties, but knowledge about this is scarce. We investigated prokaryotic community composition along the radial root axis of two European maize (Zea mays L.) landraces. A sampling gradient included bulk soil, a distal and proximal rhizosphere fraction, and the root compartment. Our study was replicated at two field locations with differing edaphic and climatic conditions. Further, we tested for differences between two plant developmental stages and two precipitation treatments. Community data were generated by metabarcoding of the V4 SSU rRNA region. While communities were generally distinct between field sites, the effects of landrace variety, developmental stage, and precipitation treatment were comparatively weak and not statistically significant. Under all conditions, patterns in community composition corresponded strongly to the distance to the root. Changes in α- and β-diversity, as well as abundance shifts of many taxa along this gradient, were similar for both landraces and field locations. Most affected taxa belonged to a core microbiome present in all investigated samples. Remarkably, we observed consistent enrichment of Actinobacteriota (particularly Streptomyces, Lechevalieria) and Pseudomonadota (particularly Sphingobium) toward the root. Further, we report a depletion of ammonia-oxidizers along this axis at both field sites. We identified clear enrichment and depletion patterns in microbiome composition along the radial root axis of Z. mays. Many of these were consistent across two distinct field locations, plant developmental stages, precipitation treatments, and for both landraces. This suggests a considerable influence of plant-mediated effects on the microbiome. We propose that the affected taxa have key roles in the rhizosphere and root microbiome of Z. mays. Understanding the functions of these taxa appears highly relevant for the development of methods aiming to promote microbiome services for crops.

Functional leaf traits of maize landraces with low and high susceptibility to damage by Spodoptera frugiperda (Lepidoptera: Noctuidae)

Functional leaf traits of maize landraces with low and high susceptibility to damage by Spodoptera frugiperda (Lepidoptera: Noctuidae)

Genetic and Phenotypic Evaluation of European Maize Landraces as a Tool for Conservation and Valorization of Agrobiodiversity.

The ECPGR European Evaluation Network (EVA) for Maize involves genebanks, research institutions, and private breeding companies from nine countries focusing on the valorization of maize genetic resources across Europe. This study describes a diverse collection of 626 local landraces and traditional varieties of maize (Zea mays L.) from nine European genebanks, including criteria for selection of the collection and its genetic and phenotypic diversity. High-throughput pool genotyping grouped the landraces into nine genetic groups with a threshold of 0.6 admixture, while 277 accessions were designated admixed and likely to have resulted from previous breeding activities. The grouping correlated well with the geographic origins of the collection, also reflecting the various pathways of introduction of maize to Europe. Phenotypic evaluations of 588 accessions for flowering time and plant architecture in multilocation trials over three years confirmed the great diversity within the collection, although phenotypic clusters only partially correlated with the genetic grouping. The EVA approach promotes conservation of genetic resources and opens an opportunity to increase genetic variability for developing improved varieties and populations for farmers, with better adaptation to specific environments and greater tolerance to various stresses. As such, the EVA maize collection provides valuable sources of diversity for facing climate change due to the varieties' local adaptation.

Genetic and Molecular Characterization of Maize Landraces from Central China

Genetic and Molecular Characterization of Maize Landraces from Central China

Genomic, climatic, and cultural diversity of maize landraces from the Himalayan Kingdom of Bhutan

Societal Impact StatementBhutan is an ancient kingdom in the Himalayan range and one of the most rugged, geodiverse, and mountainous agricultural countries in the world. Historically secluded and geographically isolated, Bhutan is a hotspot for Himalayan agrobiodiversity where small‐scale agriculture supports the livelihoods of a large share of the resident population. Here, Bhutanese maize agrobiodiversity is explored to unlock its adaptation potential using genomics and participatory variety selection in combination with climate research. We show that Bhutanese traditional farmers maintain a wealth of diversity that may support the sustainable intensification of maize cropping in the Himalayas and beyond.Summary Bhutan, an ancient kingdom enshrouded in the Himalayas, hosts largely untapped agrobiodiversity that may harness genetic variation useful for adaptation to local climates and user needs. Here, we genotyped‐by‐sequencing 351 pooled samples of local maize (Zea mays L.) landraces, the entire collection of the Bhutan National Gene Bank, comparing their genomic diversity with maize from other countries in the Himalayan range. We reconstructed the adaptation of Bhutanese maize to historical and projected climates, identifying areas of future maladaptation. We then run a common garden experiment involving local smallholder farmers in a participatory evaluation of landraces' performance, aiming at the identification of quantitative trait nucleotides (QTNs) contributing to adaptation, performance, and farmers' choice. We found that Bhutanese maize agrobiodiversity is unique in the Himalayan range, and a locus on Chromosome 5 supports the differentiation of three distinct genetic clusters. We found that a portion of current genomic diversity can be associated with the Bhutanese landscape and that maize cultivation in the southwest of the country may be negatively impacted by projected climates. We also found that Bhutanese maize agrobiodiversity is large and may contribute to adaptation and improvement. A genome‐wide association study identified 117 QTNs for climatic adaptation, agronomic performance, and farmers' preferences. Our results show that Bhutanese maize landraces are a unique source of genetic agrobiodiversity for local adaptation. We found that the integration of genomics, climate science, and participatory methods can speed up the identification of genetic factors contributing to the sustainable intensification of maize cultivation in the Himalayas and beyond.

Genetic characterization and evaluation of pigmented maize (Zea mays L.) landraces of the North East Hill Region of India-an established centre of maize diversity

Abstract The North East Hill Region (NEHR) of India is home to diverse maize landraces including pigmented accessions rich in antioxidants and nutritional properties. The present study attempted to characterize a representative collection of this mostly unexplored diversity. Altogether eighty-three local maize landraces from the seven hill states of the NEHR were studied with special emphasis on pigmentation diversity. For the morphological traits, a significant ANOVA indicated the presence of substantial genetic variability for which selection would be fruitful. A number of these accessions were found to have traits that help cope with moisture stress, improve stalk strength and optimize photosynthesis. Principal component analysis studies for the yield attributing traits indicated that ear weight was most variable. The bleaching/histological studies confirmed that anthocyanin pigment when present was always restricted to the aleurone layer of the kernels, typical of blue maize. Quantitative analysis for kernel anthocyanin/phlobaphene content also revealed genetic differences among the accessions. Genetic analysis using the model-based STRUCTURE indicated significant population structuring among the accessions. Specifically, for the pigmentation diversity studies both principal coordinate analysis and neighbour joining methods revealed near concurrent population structuring due in part to the high differentiation of seven of the twenty-one pigmentation specific loci studied. The results obtained provide comprehensive evidence of a significant amount of genetic differentiation among the landraces under study. Landraces are valuable reservoirs of favourable alleles for which selection can be made and, as in this study, identify accessions for breeding maize with enhanced levels of beneficial secondary metabolites.

Growth and yield of tropical maize landraces and commercial genotypes in Yucatan, Mexico

The state of Yucatan, known for its shallow Leptosol soils poses challenges to agriculture. Therefore, this study focused on examining ecophysiological attributes influencing the growth and yield determinants of six maize genotypes. The study assessed vegetative characteristics, growth rates, dry matter allocation, grain yield, and harvest index. All maize genotypes exhibited early maturity, a favorable trait under the climate conditions of Yucatan. Most genotypes exhibited superior growth rate and dry matter content when compared to the landrace Elotillo. Stem and grain were identified as the primary organs for dry matter accumulation, with 36% and 22% respectively. The highest grain yield was noted in hybrids Impacto and DK-390. This study provided valuable information for farmers in selecting suitable maize genotypes in Yucatan, although additional evaluations of different genotypes and management conditions are recommended.

Maize landrace and post-harvest traits are reflected in the volatile profile and nutritional composition of Italian maize porridge (Polenta): A preliminary study

Maize porridge, known as "polenta" in Italy, is a global staple food. This study aims to characterize the quality of four Italian flint maize landraces by investigating physical properties and macronutrients composition. By using SPME GC–MS and PTR-ToF-MS we analyzed the flours volatilome and changes in aroma profile post- cooking. Cooking induced the formation of 5 compounds and the loss of up to 25 compounds, primarily through evaporation. Post-cooking, the concentrations of some sulphur compounds (methanethiol, dimethyl sulfide and dimethyl trisulfide), lipid oxidation compounds (2-pentylfuran and hexanal) and Maillard reaction compounds including some aldehydes (nonanal, benzaldehyde, phenylacetaldheyde), pyridine and furans (furfural and furfuryl alcohol) increased. Differences in volatilome and macronutrients contents among landraces were also observed with Marano samples having on average a significantly higher concentration of proteins (13.67 %), while the Nostrano samples had the highest fat content (5.00 %). Fatty acid profile differences were mirrored in the volatilome. Spin flours had the highest level of linoleic acid, leading to elevated levels in cooked polenta due to linoleic acid oxidation. The differences in volatilome and macronutrients contents among the samples confirmed that local landraces are not only important for biodiversity and cultural heritage but also lead to unique aroma compounds profiles.

Comparing traditional and commercial nixtamalization of three maize landraces: impact on pozole quality and consumer acceptance

One of the most typical dishes of traditional Mexican cuisine is pozole, made with nixtamalized maize. This dish has a special place as part of the identity of Mexican culture. However, it is time-consuming to prepare. With an increasing demand for precooked maize for pozole and the limited information on its preparation process, this study aims to assess the impact of both traditional (TN) and commercial nixtamalization (CN) on the quality of processed maize and its reception by consumers, focusing on the three most popular maize landraces used in pozole recipes. This study was carried out with the Cacahuacintle (‘CAC’), Elotes Occidentales (‘EO’) and Ancho (‘AN’) landraces, which were nixtamalized using the traditional method (only lime) and the commercial method (lime + additives) and the grain was flowered. The quality of the flowered grain was determined, and a sensory analysis consisting of magnitude of difference tests, a descriptive analysis, affective test and evaluation of consumer preferences was carried out. The ‘CAC’ landrace, when processed traditionally, yielded the highest sensory and commercial quality. The ‘EO’ landrace demanded a longer flowering time, resulting in less volume but retaining the aleurone layer. This characteristic helped preserved a portion of the anthocyanins. Consistently, maize landraces subjected to traditional nixtamalization displayed higher ratings for attributes related to masa and nejayote aroma. The ‘CAC’ landrace subjected to CN faced challenges in acceptability due to odors of acetic acid and sulfuric acid. These findings underscore the importance and advantages the TN techniques. They also emphasize the need to preserve grain quality and meeting consumer preferences when exploring alternative maize processing methods for emerging markets.

Morphological and Genetic Characterization of Maize Landraces Adapted to Marginal Hills in North-West Italy.

The growing interest in maize landraces over the past two decades has led to the need to characterize the Italian maize germplasm. In Italy, hundreds of maize landraces have been developed, but only a few of them have been genetically characterized, and even fewer are currently employed in agriculture or for breeding purposes. In the present study, 13 maize landraces of the west Emilia-Romagna region were morphologically and genetically characterized. These accessions were sampled in 1954 from three provinces, Modena, Parma, and Piacenza, during the characterization project of Italian maize landraces. The morphological characterization of these 13 accessions was performed according to the UPOV protocol CPVO/TP2/3, examining 34 phenotypic traits. A total of 820 individuals were genotyped with 10 SSR markers. The genetic characterization revealed 74 different alleles, a FST mean value of 0.13, and a Nm mean of 1.73 over all loci. Moreover, AMOVA analysis disclosed a low degree of differentiation among accessions, with only 13% of genetic variability found between populations, supporting PCoA analysis results, where the first two coordinates explained only 16% of variability. Structure analysis, supported by PCoA, showed that only four accessions were clearly distinguished for both K = 4 and 6. Italian landraces can be useful resources to be employed in maize breeding programs for the development of new varieties, adapted to different environmental conditions, in order to increase crop resilience and expand the maize cultivation area.

Phenotypic characterisation and evaluation of resistance to Fusarium ear rot, fumonisin contamination and agronomic traits in a collection of maize landraces

Context Maize is a major crop in Italy and is constantly affected by the fungus Fusarium verticillioides, producing ear rot and grain contamination by fumonisins. Finding new genotypes resistant to Fusarium infection is an important goal for the improvement of maize cultivation. Aims The objective of this work was to test a collection of 33 traditional landraces from the Emilia-Romagna (Italy) region for Fusarium ear rot (FER) severity, fumonisin content, and their agronomic performance. Methods Primary ears were artificially inoculated with a toxigenic strain of F. verticillioides in a 2-year experimental trial. The landrace ‘Nostrano di Storo’ and a commercial hybrid of FAO maturity class 300 were also included and used as comparisons representing a well-known and highly valued landrace and a modern flint hybrid, respectively. Key results The collection showed great phenotypic variability for all the agronomic traits assessed and responded differently to the Fusarium infection with percentages of FER ranging from 6.6% to 49.3%, and fumonisins from 4.3 mg/kg to 34.5 mg/kg. Thirteen and six landraces displayed FER percentages and fumonisin content very similar to the hybrid, respectively. Moreover, eight landraces exhibited grain yield values comparable to the hybrid. Interestingly, Va221, Va227 and EMR03 showed the best combination among these three traits. Conclusions This local material can be considered suitable for breeding purposes targeting the development of FER and fumonisin resistant germplasm. Implications The collection may represent a resource for future research aimed at evaluating the response to multiple pathogens and their associated mycotoxins.

Genomic prediction within and across maize landrace derived populations using haplotypes.

Genomic prediction (GP) using haplotypes is considered advantageous compared to GP solely reliant on single nucleotide polymorphisms (SNPs), owing to haplotypes' enhanced ability to capture ancestral information and their higher linkage disequilibrium with quantitative trait loci (QTL). Many empirical studies supported the advantages of haplotype-based GP over SNP-based approaches. Nevertheless, the performance of haplotype-based GP can vary significantly depending on multiple factors, including the traits being studied, the genetic structure of the population under investigation, and the particular method employed for haplotype construction. In this study, we compared haplotype and SNP based prediction accuracies in four populations derived from European maize landraces. Populations comprised either doubled haploid lines (DH) derived directly from landraces, or gamete capture lines (GC) derived from crosses of the landraces with an inbred line. For two different landraces, both types of populations were generated, genotyped with 600k SNPs and phenotyped as lines per se for five traits. Our study explores three prediction scenarios: (i) within each of the four populations, (ii) across DH and GC populations from the same landrace, and (iii) across landraces using either DH or GC populations. Three haplotype construction methods were evaluated: 1. fixed-window blocks (FixedHB), 2. LD-based blocks (HaploView), and 3. IBD-based blocks (HaploBlocker). In within population predictions, FixedHB and HaploView methods performed as well as or slightly better than SNPs for all traits. HaploBlocker improved accuracy for certain traits but exhibited inferior performance for others. In prediction across populations, the parameter setting from HaploBlocker which controls the construction of shared haplotypes between populations played a crucial role for obtaining optimal results. When predicting across landraces, accuracies were low for both, SNP and haplotype approaches, but for specific traits substantial improvement was observed with HaploBlocker. This study provides recommendations for optimal haplotype construction and identifies relevant parameters for constructing haplotypes in the context of genomic prediction.

Unraveling root and rhizosphere traits in temperate maize landraces and modern cultivars: Implications for soil resource acquisition and drought adaptation.

A holistic understanding of plant strategies to acquire soil resources is pivotal in achieving sustainable food security. However, we lack knowledge about variety-specific root and rhizosphere traits for resource acquisition, their plasticity and adaptation to drought. We conducted a greenhouse experiment to phenotype root and rhizosphere traits (mean root diameter [Root D], specific root length [SRL], root tissue density, root nitrogen content, specific rhizosheath mass [SRM], arbuscular mycorrhizal fungi [AMF] colonization) of 16 landraces and 22 modern cultivars of temperate maize (Zea mays L.). Our results demonstrate that landraces and modern cultivars diverge in their root and rhizosphere traits. Although landraces follow a 'do-it-yourself' strategy with high SRLs, modern cultivars exhibit an 'outsourcing' strategy with increased mean Root Ds and a tendency towards increased root colonization by AMF. We further identified that SRM indicates an 'outsourcing' strategy. Additionally, landraces were more drought-responsive compared to modern cultivars based on multitrait response indices. We suggest that breeding leads to distinct resource acquisition strategies between temperate maize varieties. Future breeding efforts should increasingly target root and rhizosphere economics, with SRM serving as a valuable proxy for identifying varieties employing an outsourcing resource acquisition strategy.

Development of high-yielding white maize hybrids with better chapatti-making quality compared to traditionally used local landraces.

The present research focuses on the chapatti making quality of high-yielding white maize hybrids compared to available low-yielding local yellow and white landraces in India. In this study, the top nine superior hybrids were selected for testing the physical properties of the maize kernels, proximate composition of flours and chapattis, physical parameters of chapatti, textural properties, sensory evaluation of chapattis and pasting properties of maize flour. The results revealed the superiority of white maize hybrids (WMH), viz., WHM 1, WHM 2, and WHM 8 over the local yellow and white landraces for most of the parameters studied. In sensory analysis, though, the yellow landrace was considered superior by the panellists in terms of colour but the white maize hybrids outperformed in overall sensory analysis and were more acceptable than the yellow and white maize landraces. These high yielding white maize hybrids with good consumer acceptance may cater for the needs of rural and tribal populations in India who prefer white maize as a staple food.