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This study aims to provide a theoretical basis for screening continuous rain tolerant germplasm materials of maize tassels by studying the effects of continuous rain on the development of maize tassels. In the study, 73 maize inbred lines and 14 maize hybrid combinations were used as experimental materials to determine the characteristics related to maize tassel abortion, including tassel length, main axis length, main axis abortion length, first lateral branch length, first lateral branch abortion length, main axis abortion rate, and first lateral branch abortion rate after 6 days of continuous rain. Genetic variation and principal component clustering analysis were conducted. The results showed that under continuous rain, the tassel abortion characteristics of maize inbred lines and hybrid combinations showed rich variation. The main axis abortion rates of inbred lines and hybrid combinations were 0-100% and 18.40%-100%, respectively, with an average of 37.15% and 35.16%. The abortion rates of the first lateral branch were 0-100% and 8.59%-100%, respectively, with an average of 38.48% and 46.31%. According to the characteristics of tassel abortion, both inbred lines and hybrid combinations could be classified into three categories. The first category of inbred lines and hybrid combinations consisted of 34 and 4 materials, respectively. The tassel, main axis, and first lateral branch were longer, but the main axis abortion rate and first lateral branch abortion rate were lower, indicating a continuous rain tolerance type. There were 24 and 9 materials in the second type of inbred lines and hybrid combinations, respectively. The tassel, main axis, and first lateral branch were shorter, but the tassel main axis abortion rate and first lateral branch abortion rate were higher, indicating a continuous rain sensitive type. There were 15 inbred lines and 1 hybrid combination in type III materials, respectively, with a moderate degree of tassel abortion. 34 inbred lines and 4 hybrid combinations were selected as the continuous rain tolerant materials for tassels. [ABSTRACT FROM AUTHOR]

The intelligent acquisition of phenotypic information on male tassels is critical for maize growth and yield assessment. In order to realize accurate detection and density assessment of maize male tassels in complex field environments, this study used a UAV to collect images of maize male tassels under different environmental factors in the experimental field and then constructed and formed the ESG-YOLO detection model based on the YOLOv7 model by using GELU as the activation function instead of the original SiLU and by adding a dual ECA attention mechanism and an SPD-Conv module. And then, through the model to identify and detect the male tassel, the model's average accuracy reached a mean value (mAP) of 93.1%; compared with the YOLOv7 model, its average accuracy mean value (mAP) is 2.3 percentage points higher. Its low-resolution image and small object target detection is excellent, and it can be more intuitive and fast to obtain the maize male tassel density from automatic identification surveys. It provides an effective method for high-precision and high-efficiency identification of maize male tassel phenotypes in the field, and it has certain application value for maize growth potential, yield, and density assessment. [ABSTRACT FROM AUTHOR]

Eco-friendly materials receive more attention due to the necessity of addressing pollution and resource depletion in the face of exponential industrial expansion. Natural fibers provide a sustainable substitution, especially in green composites. This study investigated the feasibility of Allium fistulosum L. (Scallion) as a fiber resource for composite applications by using its tassel. Allium fistulosum L. is derived from a widely available plant and its waste tassels of the plant provide fiber properties and have the potential to be a reinforcing component in composites. The investigation involves characterizing Allium fistulosum L. (AfL) fibers through various analyses. The density of the AfL was determined approximately 1.35 - 1.45 g/cm3. The percentages of lignin, hemicellulose, and cellulose were found to be 24.31%, 29.73%, and 38.36%, respectively. FTIR and XRD analysis affirm AfL's cellulose, hemicellulose, and lignin presence. SEM images indicate a rough surface, necessitating modification for better matrix compatibility. TGA shows suitable thermal stability, majorly degrading beyond 267°C. Tensile testing demonstrates a tensile strength of 22.19 ±3.75 MPa and 0.87 ±0.16 GPa modulus, exceeding some natural fibers like aerial banyan tree roots and Cordia dichotoma. Results show promising features, indicating the viability of AfL fibers in composites with reduced environmental impact and economic benefits. [ABSTRACT FROM AUTHOR]

High temperature (HT) at flowering hinders pollen shedding, but the mechanisms underlying stress-induced spikelet closure are poorly understood in maize. In this study, yield components, spikelet opening, and lodicule morphology/protein profiling upon HT stress during flowering were examined in two contrasting maize inbred lines, Chang 7-2 and Qi 319. HT induced spikelet closure and reduced pollen shed weight (PSW) and seed set in both lines, but Qi 319 had a 7-fold lower PSW than Chang 7-2, and was thus more susceptible to HT. In Qi 319, a smaller lodicule size reduced the spikelet opening rate and angle, and relatively more vascular bundles hastened lodicule shrinking compared with Chang 7-2. Lodicules were collected for proteomics analysis. In lodicules of HT-stressed plants, proteins involved in stress signals, cell wall, cell constructure, carbohydrate metabolism, and phytohormone signaling were associated with stress tolerance. HT down-regulated the expression of ADP-ribosylation factor GTPase-activating protein domain2 , SNAP receptor complex member11 , and sterol methyltransferase2 in Qi 319 but not in Chang 7-2, which was in good agreement with the observed changes in protein abundance. Exogenous epibrassinolide increased the spikelet opening angle and extended the duration of spikelet opening. These results suggest that dysfunction of the actin cytoskeleton and membrane remodeling induced by HT probably limits lodicule expansion. In addition, a reduction in the vascular bundles in the lodicules and application of epibrassinolide might confer spikelet tolerance to HT stress. [ABSTRACT FROM AUTHOR]

The genome‐wide association studies (GWASs) are essential to determine the genetic bases of either ecological or economic phenotypic variation across individuals within populations of the model and nonmodel organisms. For this research question, the GWAS replication testing different parameters and models to validate the results' reproducibility is common. However, straightforward methodologies that manage both replication and tetraploid data are still missing. To solve this problem, we designed the MultiGWAS, a tool that does GWAS for diploid and tetraploid organisms by executing in parallel four software packages, two designed for polyploid data (GWASpoly and SHEsis) and two designed for diploid data (GAPIT and TASSEL). MultiGWAS has several advantages. It runs either in the command line or in a graphical interface; it manages different genotype formats, including VCF. Moreover, it allows control for population structure, relatedness, and several quality control checks on genotype data. Besides, MultiGWAS can test for additive and dominant gene action models, and, through a proprietary scoring function, select the best model to report its associations. Finally, it generates several reports that facilitate identifying false associations from both the significant and the best‐ranked association Single Nucleotide Polymorphisms (SNPs) among the four software packages. We tested MultiGWAS with public tetraploid potato data for tuber shape and several simulated data under both additive and dominant models. These tests demonstrated that MultiGWAS is better at detecting reliable associations than using each of the four software packages individually. Moreover, the parallel analysis of polyploid and diploid software that only offers MultiGWAS demonstrates its utility in understanding the best genetic model behind the SNP association in tetraploid organisms. Therefore, MultiGWAS probed to be an excellent alternative for wrapping GWAS replication in diploid and tetraploid organisms in a single analysis environment. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Micronutrient deficiency is a serious and underestimated global health concern. Identifying existing micronutritional richness in traditional crops, and breeding this potential into staple crops that are more frequently consumed, could offer a potential low‐cost, sustainable solution to micronutrient deficiency. Here, we provide the first insight into genetic control of grain micronutrient content in the staple food crop finger millet (Eleusine coracana). Quantifying the existing natural variation in nutritional traits, and identifying the regions of the genome associated with these traits, will underpin future breeding efforts to improve not only global food and nutrition security, but also human health. Summary: Finger millet is an excellent cereal crop to alleviate micronutrient malnutrition in marginal communities because of its nutrient‐dense grains. Identification of the alleles governing these characteristics will help to develop improved germplasm.An assembly of 190 genotypes was evaluated for six minerals (iron, zinc, calcium, magnesium, potassium, and sodium) and protein content. A combination of genotyping‐by‐sequencing (GBS) and genome‐wide association study (GWAS) was applied to identify marker‐trait associations (MTAs). Candidate genes underlying significant associations were predicted through comparative mapping with other cereals.A wide range of variation was observed for all traits. GBS generated 169,365 single‐nucleotide polymorphisms and three subpopulations were identified. GWAS, using general linear and mixed model approaches to correct for population structure and genetic relatedness, identified 418 common markers (p‐value ≤ 10–3, FDR < 0.1) linked with mineral content. Of these, 34 markers crossed the Bonferroni threshold, out of which 18 showed homology with candidate genes having putative functions in binding, remobilization or transport of metal ions.This is the first report to utilize the phenotypic variability of grain minerals in finger millet genotypes to identify MTAs and predict associated putative candidate genes. Postvalidation, these markers may be employed to improve grain nutrient quality through marker‐assisted breeding. [ABSTRACT FROM AUTHOR]

Inflorescence capacity plays a crucial role in reproductive fitness in plants, and in production of hybrid crops. Maize is a monoecious species bearing separate male and female flowers (tassel and ear, respectively). The switch from open-pollinated populations of maize to hybrid-based breeding schemes in the early 20th century was accompanied by a dramatic reduction in tassel size, and the trend has continued with modern breeding over the recent decades. The goal of this study was to identify selection signatures in genes that may underlie this dramatic transformation. Using a population of 942 diverse inbred maize accessions and a nested association mapping population comprising three 200-line biparental populations, we measured 15 tassel morphological characteristics by manual and image-based methods. Genome-wide association studies identified 242 single nucleotide polymorphisms significantly associated with measured traits. We compared 41 unselected lines from the Iowa Stiff Stalk Synthetic (BSSS) population to 21 highly selected lines developed by modern commercial breeding programs, and found that tassel size and weight were reduced significantly. We assayed genetic differences between the two groups using three selection statistics: cross population extended haplotype homozogysity, cross-population composite likelihood ratio, and fixation index. All three statistics show evidence of selection at genomic regions associated with tassel morphology relative to genome-wide null distributions. These results support the tremendous effect, both phenotypic and genotypic, that selection has had on maize male inflorescence morphology. [ABSTRACT FROM AUTHOR]

Tassel architecture is an important trait in maize breeding and hybrid seed production. In this study, we investigated total tassel length (TTL) and tassel branch number (TBN) in 266 F2:3 families across six environments and in 301 recombinant inbred lines (RILs) across three environments, where all the plants were derived from a cross between 08-641 and Ye478. We compared the genetic architecture of the two traits across two generations through combined analysis. In total, 27 quantitative trait loci (QTLs) (15 in F2:3; 16 in RIL), two QTL × environment interactions (both in F2:3), 11 pairs of epistatic interactions (seven in F2:3; four in RIL) and four stable QTLs in both the F2:3 and RILs were detected. The RIL population had higher detection power than the F2:3 population. Nevertheless, QTL × environment interactions and epistatic interactions could be more easily detected in the F2:3 population than in the RILs. Overall, the QTL mapping results in the F2:3 and RILs were greatly influenced by genetic generations and environments. Finally, fine mapping for a novel and major QTL, qTTL-2-3 (bin 2.07), which accounted for over 8.49% of the phenotypic variation across different environments and generations, could be useful in marker-assisted breeding. [ABSTRACT FROM AUTHOR]

Maize ( Zea mays) tassels underwent profound morphological changes during maize domestication and improvement. Although a number of genes affecting maize inflorescence development have been identified, the genetic basis of the morphological changes in maize tassels since domestication is not well understood., Here, using a large population of 866 maize-teosinte BC2S3 recombinant inbred lines genotyped using 19 838 single nucleotide polymorphism ( SNP) markers, we performed high-resolution quantitative trait locus ( QTL) mapping for five tassel morphological traits., We showed that the five tassel traits were associated with different genetic architecture features. Known genes for maize inflorescence development identified by mutagenesis were significantly enriched in the tassel trait QTLs, and many of these genes, including ramosa1 ( ra1), barren inflorescence2 ( bif2), unbranched2 ( ub2), zea floricaula leafy2 ( zfl2) and barren stalk fastigiate1 ( baf1), showed evidence of selection. An in-depth nucleotide diversity analysis at the bif2 locus identified strong selection signatures in the 5′-regulatory region. We also found that several known flowering time genes co-localized with tassel trait QTLs. A further association analysis indicated that the maize photoperiod gene Zm CCT was significantly associated with tassel size variation. Using near-isogenic lines, we narrowed down a major-effect QTL for tassel length, qTL9-1, to a 513-kb physical region., These results provide important insights into the genetic architecture that controls maize tassel evolution. [ABSTRACT FROM AUTHOR]

Background: The maize male inflorescence (tassel) produces pollen necessary for reproduction and commercial grain production of maize. The size of the tassel has been linked to factors affecting grain yield, so understanding the genetic control of tassel architecture is an important goal. Tassels are fragile and deform easily after removal from the plant, necessitating rapid measurement of any shape characteristics that cannot be retained during storage. Some morphological characteristics of tassels such as curvature and compactness are difficult to quantify using traditional methods, but can be quantified by image-based phenotyping tools. These constraints necessitate the development of an efficient method for capturing natural-state tassel morphology and complementary automated analytical methods that can quickly and reproducibly quantify traits of interest such as height, spread, and branch number. Results: This paper presents the Tassel Image-based Phenotyping System (TIPS), which provides a platform for imaging tassels in the field immediately following removal from the plant. TIPS consists of custom methods that can quantify morphological traits from profile images of freshly harvested tassels acquired with a standard digital camera in a field-deployable light shelter. Correlations between manually measured traits (tassel weight, tassel length, spike length, and branch number) and image-based measurements ranged from 0.66 to 0.89. Additional tassel characteristics quantified by image analysis included some that cannot be quantified manually, such as curvature, compactness, fractal dimension, skeleton length, and perimeter. TIPS was used to measure tassel phenotypes of 3530 individual tassels from 749 diverse inbred lines that represent the diversity of tassel morphology found in modern breeding and academic research programs. Repeatability ranged from 0.85 to 0.92 for manually measured phenotypes, from 0.77 to 0.83 for the same traits measured by image-based methods, and from 0.49 to 0.81 for traits that can only be measured by image analysis. Conclusions: TIPS allows morphological features of maize tassels to be quantified automatically, with minimal disturbance, at a scale that supports population-level studies. TIPS is expected to accelerate the discovery of associations between genetic loci and tassel morphology characteristics, and can be applied to maize breeding programs to increase productivity with lower resource commitment. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effect of silicon fertilization on physiological parameter and yield of hybrid maize under irrigated and rainfed conditions during Rabi, 2017-18 at eastern block farm of Tamil Nadu Agricultural University, Coimbatore. The treatments comprised of two factorsviz., three irrigation strategies and two silicon sources as seed priming and foliar application. The results of the study indicated that adequate irrigation strategy registered significantly higher physiological parameters, grain yield (6679 kg/ha) and stoveryield. Silicon application as seed priming with 1.5 mM of sodium meta silicate and foliar application of silicic acid @ 0.2% at knee high and tassel initiation stages was recordedhigher physiological parameter like SPAD meter value and Relative Water Content (RWC) and grain (6130 kg/ha) and stoveryield. It was comparable with foliar application of silicic acid @ 0.2% at knee high and tassel initiation stages alone in registering higher growth and yield of maize. [ABSTRACT FROM AUTHOR]

Background: Hop is an economically important crop for the Pacific Northwest USA as well as other regions of the world. It is a perennial crop with rhizomatous or clonal propagation system for varietal distribution. A big concern for growers as well as brewers is variety purity and questions are regularly posed to public agencies concerning the availability of genotype testing. Current means for genotyping are based upon 25 microsatellites that provides relatively accurate genotyping but cannot always differentiate sister-lines. In addition, numerous PCR runs (25) are required to complete this process and only a few laboratories exist that perform this service. A genotyping protocol based upon SNPs would enable rapid accurate genotyping that can be assayed at any laboratory facility set up for SNP-based genotyping. The results of this study arose from a larger project designed for whole genome association studies upon the USDA-ARS hop germplasm collection consisting of approximately 116 distinct hop varieties and germplasm (female lines) from around the world. Results: The original dataset that arose from partial sequencing of 121 genotypes resulted in the identification of 374,829 SNPs using TASSEL-UNEAK pipeline. After filtering out genotypes with more than 50 % missing data (5 genotypes) and SNP markers with more than 20 % missing data, 32,206 highly filtered SNP markers across 116 genotypes were identified and considered for this study. Minor allele frequency (MAF) was calculated for each SNP and ranked according to the most informative to least informative. Only those markers without missing data across genotypes as well as 60 % or less heterozygous gamete calls were considered for further analysis. Genetic distances among individuals in the study were calculated using the marker with the highest MAF value, then by using a combination of the two markers with highest MAF values and so on. This process was reiterated until a set of markers was identified that allowed for all genotypes in the study to be genetically differentiated from each other. Next, we compared genetic matrices calculated from the minimal marker sets [(Table 2; 6-, 7-, 8-, 10- and 12-marker set matrices] and that of a matrix calculated from a set of markers with no missing data across all 116 samples (1006 SNP markers). The minimum number of markers required to meet both specifications was a set of 7-markers (Table 3). These seven SNPs were then aligned with a genome assembly, and DNA sequence both upstream and downstream were used to identify primer sequences that can be used to develop seven amplicons for high resolution melting curve PCR detection or other SNP-based PCR detection methods. Conclusions: This study identifies a set of 7 SNP markers that may prove useful for the identification and validation of hop varieties and accessions. Variety validation of unknown samples assumes that the variety under question has been included a priori in a discovery panel. These results are based upon in silica studies and markers need to be validated using different SNP marker technology upon a differential set of hop genotypes. The marker sequence data and suggested primer sets provide potential means to fingerprint hop varieties in most genetic laboratories utilizing SNP-marker technology. [ABSTRACT FROM AUTHOR]

tassel-less1 (tls1) is a classical maize (Zea mays) inflorescence mutant. Homozygous mutant plants have no tassels or very small tassels, and ear development is also impaired. Using a positional cloning approach, ZmNIP3;1 (a NOD26-like intrinsic protein) was identified as the candidate gene for tls1. The ZmNIP3;1 gene is completely deleted in the tls1 mutant genome. Two Mutator-insertional TUSC alleles of ZmNIP3;1 exhibited tls1-like phenotypes, and allelism tests confirmed that the tls1 gene encodes ZmNIP3;1. Transgenic plants with an RNA interference (RNAi) construct to down-regulate ZmNIP3;1 also showed tls1-like phenotypes, further demonstrating that TLS1 is ZmNIP3;1. Sequence analysis suggests that ZmNIP3;1 is a boron channel protein. Foliar application of boron could rescue the tls1 phenotypes and restore the normal tassel and ear development. Gene expression analysis indicated that in comparison with that of the wild type or tls1 plants treated with boron, the transition from the vegetative to reproductive phase or the development of the floral meristem is impaired in the shoot apical meristem of the tls1 mutant plants. It is concluded that the tls1 mutant phenotypes are caused by impaired boron transport, and boron is essential for inflorescence development in maize. [ABSTRACT FROM PUBLISHER]

Working group of Agricultural University of Tirana, supported by Seednet Project, collected some local maize populations during 2009-2010 in different areas of Albania. The genetic material need to characterization and evaluation for preservation at Gene Bank. The evaluation process involved the following elements: to male flowering, female flowering, during of plant period, plant height, ear height, stay green, number of leaves above the uppermost ear including ear leaf, stem color, tassel type. The results showed that the evaluated landraces have difference from our investigation, it emerged that the difference between the male flowering and female flowering was 2-9 days and the plant period was short in most part of the populations. The short vegetative period made possible the increase of their cultivation in the hill and mountain areas and in areas without irrigation. The statistical cluster analyses was accomplished the data collected on morph biological descriptors, processed through by Hierarchical Clustering Method and identified three varietal groups characterized according to metrical parameters and the locations of origin are identified. [ABSTRACT FROM AUTHOR]

One of the main wheat breeder's goals is determining specific genomic regions which control important agronomical traits. Association analysis is a new strategy with high resolution in plant molecular breeding that could be used to improve the efficiency of marker assisted selection (MAS) for finding important QTLs (quantitative trait loci) or genes. A set of 96 diverse wheat genotypes was phenotypically measured during three growing seasons (2006/07, 2007/08, 2008/09). Microsatellite markers located near important QTLs were carefully chosen in accordance with existing literature data to validate marker trait associations (MTA). Genomic DNA was extracted using the CTAB method and PCR products were separated by capillary electrophoresis. The population structure was assigned based on molecular data in Structure v. 2.0 software, while association analysis was done by the Tassel program using the Q matrix. Nine significant associations were stable in all years investigated and eight MTA were detected to be significant in two growing seasons. Microsatellite markers which showed significant associations and stability in different seasons can be useful and suitable for marker assisted selection (MAS) in Serbian wheat breeding programs. [ABSTRACT FROM AUTHOR]

Boron (B) deficiency depresses wheat, barley and triticale yield through male sterility. On the basis of field responses to B fertilization, maize ( Zea mays L.) is affected by B deficiency in five continents. In a series of sand culture trials with maize subject to B0 (nil added B) and B20 (20 μM added B) treatments, we described how B deficiency depressed maize grain yield while showing an imperceptible effect on vegetative dry weight. With manual application of pollen to the silk of each plant, B0 plants produced 0.4 grain ear compared with 410 grains ear in B20 plants. Symptoms of B deficiency was observed only in B0 plants, which exhibited symptoms of narrow white to transparent lengthwise streaks on leaves, multiple but small and abnormal ears with very short silk, small tassels with some branches emerging dead, and small, shrivelled anthers devoid of pollen. Tassels, silk and pollen of B0 plants contained only 3-4 mg B kg DW compared with twice or more B in these reproductive tissues in B20 plants. A cross-fertilization experiment showed that, although the tassels and pollen were more affected, the silk was more sensitive to B deficiency. Pollen from B20 plants applied to B0 silk produced almost no grains, while pollen from B0 on B20 silk increased the number of grains to 37% of the 452 grains plant produced from B20 pollen on B20 silk. Therefore, the silk of the first ear may be targeted for precise diagnosis of B status at maize reproduction, for timely correction by foliar B application, and even for B-efficient genotype selection. [ABSTRACT FROM AUTHOR]

Finger millet is a nutritious cereal and marker assisted breeding is essential for the identification of genes/alleles governing quality traits in finger millet. This study used an integrated breeding strategy supported by genomics, where selective genotyping of 113 diverse finger millet genotypes was carried out for understanding the complex genetic architecture of SPC (seed protein content) and related traits like DM (days to maturity) and GY (grain yield) in two geographically different locations in India i.e. Almora (E1) and Pantnagar (E2). Significant differences among genotypes were observed for SPC, DM and GY in both the locations. A set of 2977 genome-wide SNPs identified through genotyping by sequencing were used for MTA analysis. GLM resulted in 7, 10 and 9, while MLM found 4, 9 and 7 MTA's for SPC, DM and GY, respectively across the locations using TASSEL pipeline. Among GLM and MLM 4, 7 and 6 MTA's were found common for SPC, DM and GY, respectively. Another pipeline, GAPIT identified 12 MTA's each for SPC, DM and 11 MTA's for GY across the locations. NCBI blast of common SNP markers for all three traits resulted in 5, 3 and 5 most effective genome regions associated with SPC, DM and GY. Among them, the SNP responsible for gene encoding aspartyl protease exhibited strong SPC association and was found to be the most promising candidate for protein content variation in finger millet. For GY and DM, ATP synthase gene which catalyses the addition of a phosphate to ADP, capturing energy from the proton gradient as ATP was found prominent gene. Expression results for five genes associated with SPC showed higher transcript accumulation in high protein containing genotype in comparison to low protein containing genotype. Image 1 • Significant genotypic differences were observed for SPC, DM and GY in E1 & E2. • Five SNPs were found to be significantly associated with SPC, GY and three with DM trait in finger millet. • Aspartyl protease was found as most promising candidate gene governing SPC content in finger millet grains. [ABSTRACT FROM AUTHOR]