Waxy corn and sweet corn represent 2 major classes of fresh-eating corn, each with distinct sensory attributes and nutritional compositions. Developing a new variety that combines both waxy and sweet traits would address rising consumer demand and expand new market potential. From a fast neutron-mutagenized population of the waxy corn inbred line HB522, we isolated a novel mutant, designated as wx-sweet, whose kernels simultaneously exhibit waxy and sweet characteristics at the milk-filling stage. Through bulked segregant analysis combined with fine mapping, we mapped the causal locus to SHRUNKEN1 (Sh1) on chromosome 9, which was confirmed by an allelism test with a characterized Mu-insertion allele of Sh1. A 7,227-bp Copia-type long terminal repeat retrotransposon insertion was identified in exon 2 of Sh1 in the wx-sweet mutant by long-read sequencing. Consistently, the novel sh1 allele significantly reduced sucrose synthase activity. Genetic and physiological analyses demonstrate that sh1 and wx1 act synergistically to fine-tune carbohydrate metabolism in the endosperm. Integrated transcriptomic and metabolomic profiling uncover extensive transcriptional reprogramming and redirected metabolic flux, leading to substantial accumulation of sucrose and a range of oligosaccharides. These metabolic shifts underlie the unique simultaneous dual waxy-sweet texture in fresh-eating wx-sweet kernels. In summary, our work not only provides valuable genetic resources for breeding next-generation fresh-eating corn but also, for the first time, elucidates the molecular mechanism by which the sh1 and wx1 mutations cooperatively shape the waxy-sweet endosperm phenotype.

[Objective]Moisture content and kernel hardness are key indicators for evaluating the eating quality and harvest maturity of fresh corn. Accurate and simultaneous prediction of the two parameters is essential for quality grading and post-harvest management. However, conventional near-infrared spectroscopy (NIRS) methods are mostly based on single-point measurements, which are easily affected by husk shielding and kernel heterogeneity, resulting in limited prediction accuracy, especially for multi-attribute estimation. Spatially resolved spectroscopy, by acquiring spectral information from multiple measurement channels, can better reflect internal quality differences of corn kernels. Nevertheless, the high dimensionality and strong correlation of spatially resolved spectral data, together with the heterogeneity between different prediction tasks, pose significant challenges to traditional modeling approaches. Therefore, the purpose of this research was to develop an effective multi-task prediction model that can fully exploit spatially resolved spectral information while balancing feature sharing and task specificity for moisture content and kernel hardness prediction in husked fresh corn.[Methods]Husk-on fresh corn samples were collected across different maturity stages to ensure sufficient variability in moisture content and kernel hardness. A multi-channel visible-near infrared spatially resolved spectroscopy system was constructed to acquire spectral signals from four spatial measurement channels at different source-detector distances. Each corn ear was segmented into multiple positions, and spectral data were collected from different spatial locations to comprehensively capture internal quality information. In total, 500 valid spectral samples were obtained and randomly divided into training, validation, and test sets at a ratio of 7:1:2. Before modeling, the raw spectral data were preprocessed using z-score standardization to eliminate scale differences among channels and wavelengths and to improve numerical stability during training. The proposed MaMoNet (Mamba-MMoE Network) model is composed of three main modules: a one-dimensional convolutional neural network (1D-CNN) for local feature extraction, a Mamba-based sequence modeling module for global dependency learning, and a Multi-gate Mixture-of-Experts (MMoE) module for task-adaptive feature allocation. First, the 1D-CNN module was employed to extract low-level local spectral patterns and reduce feature redundancy. The input spectral data were processed by two successive one-dimensional convolutional layers and down sampling was then applied to compress the spectral length, resulting in a more compact representation and reducing the computational burden for subsequent sequence modeling. Next, the compressed spectral features were fed into the Mamba module to capture long-range dependencies along the spectral dimension. Mamba is a selective state space model that enables efficient modeling of long spectral sequences by dynamically updating hidden states, allowing global spectral evolution patterns to be effectively learned with linear computational complexity. Finally, the output features of the Mamba module were input into an MMoE module to support multi-task learning of moisture content and kernel hardness. Multiple expert networks were shared across tasks, and task-specific gating networks were used to adaptively weight expert outputs, enabling flexible feature sharing and task-specific representation learning. The task-specific features were then passed to individual regression heads to generate the final predictions for moisture content and kernel hardness. To comprehensively evaluate the effectiveness of the proposed approach, MaMoNet was compared with several representative multi-task convolutional neural network models. In addition, ablation experiments were conducted by selectively removing the Mamba module or the MMoE module to analyze their individual contributions to overall performance.[Results and Discussions]Experimental results demonstrated that the proposed MaMoNet model consistently outperformed all comparison models on the test set for both prediction tasks. For moisture content prediction, MaMoNet achieved a coefficient of determination (R2) of 0.91, a root mean square error (RMSE) of 4.98%, and a residual predictive deviation (RPD) of 3.40, indicating excellent predictive accuracy and robustness. For kernel hardness prediction, the corresponding R2, RMSE, and RPD values reached 0.89, 3.46 N, and 3.06, respectively, which also surpassed those of the benchmark models. The ablation study further verified the rationality of the proposed model design. Removing both the Mamba and MMoE modules resulted in the poorest performance, whereas introducing either module individually led to noticeable improvements. The best prediction results were achieved when both modules were jointly employed, indicating that their combination was critical for achieving optimal multi-task prediction performance. These results indicated that moisture content and kernel hardness, although correlated, emphasize different spectral characteristics. The flexible feature-sharing mechanism enabled by MMoE allows the model to balance information sharing and task specificity, while the Mamba module ensures effective utilization of long-range spectral information. Together, they contribute to improved generalization performance under limited sample conditions.[Conclusions]This study proposes a MaMoNet model that integrates Mamba-based state space modeling with an MMoE-based multi-task learning strategy for simultaneous prediction of moisture content and kernel hardness in husked fresh corn using spatially resolved spectroscopy. The proposed approach effectively overcomes the limitations of conventional single-point spectral analysis and rigid parameter-sharing multi-task models. Experimental comparisons and ablation analyses confirm that MaMoNet achieves improved accuracy, robustness, and generalization capability. The results demonstrate the potential of the proposed framework for rapid and non-destructive quality assessment of fresh corn and provide useful methodological insights for multi-attribute prediction based on high-dimensional spectral data.

Background: During maize anthesis, heat stress severely limits productivity—particularly under humid conditions where high humidity suppresses transpirational cooling, forcing tissues to endure direct thermal load. Methods: Using field enclosures to impose enclosure-imposed humid heat shock (EHS), we screened 135 maize inbred lines for flowering-stage yield resilience, using grain weight per ear at maturity under EHS relative to the corresponding control (CK) condition as the primary selection criterion. Based on this screen, we selected two tolerant (R025, R100) and two sensitive (R133, R135) genotypes for data-independent acquisition mass spectrometry (DIA-MS) profiling of the tassel-subtending leaf. Results: At baseline, the selected tolerant lines exhibited a constitutively distinct proteomic state, including lower abundance of light-harvesting complex components and higher abundance or detection frequency of several regulatory proteins, including SRK2E/OST1 and HSF-B2a. Under sustained EHS, the selected sensitive lines showed extensive proteomic disruption, including reduced abundance of photosynthesis-related proteins and oxidative phosphorylation, together with increased abundance of proteins associated with endoplasmic reticulum stress responses and protein turnover. In contrast, the selected tolerant lines displayed a more constrained acclimation response, characterized by relative maintenance of photosynthesis-related proteins together with selective increases in chaperone systems (HSP90/sHSPs) and benzoxazinoid biosynthesis-related proteins. Several proteins showed switch-like detection patterns between the selected tolerant and sensitive lines, including TMEM97-like and a peptidyl-prolyl isomerase, indicating potentially distinct regulatory states. Conclusions: These findings suggest that tolerant performance under enclosure-imposed heat stress is associated with a pre-conditioned proteomic state and enhanced protein homeostasis (proteostasis) buffering capacity that may help preserve photosynthetic function during flowering-stage stress. The identified proteins should be regarded as candidate markers requiring further functional validation before any application in breeding programs aimed at improving adaptation to increasingly frequent heat-stress events.

Leaf senescence induced by high temperature (HT) has become a primary factor limiting maize yield, particularly during the filling stage. Exogenous salicylic acid (SA) has emerged as an effective strategy to mitigate leaf senescence and HT-induced damage, though its underlying mechanisms remain unclear. This study investigated the regulatory mechanism of SA application on waxy maize subjected to HT during the early filling stage. Compared to HT alone, exogenous SA alleviated the inhibition of photosynthesis and oxidative damage by enhancing the activities of enzymes involved in photosynthesis and antioxidant system and modulating phytohormone metabolism and signal transduction pathways, thereby reducing leaf senescence and mitigating yield loss under HT. Transcriptomic and metabolomic analyses showed that HT downregulated most genes involved in the starch and sucrose metabolism pathway in leaves but promoted soluble sugar accumulation, which represents a plant strategy to cope with HT. Conversely, exogenous SA reversed this change and further enhanced soluble sugar accumulation in leaves. SA also regulated sugar metabolism by inhibiting trehalose-6-phosphate synthesis and activating SnRK1 to resist HT. Furthermore, SA stimulated lignin biosynthesis through the phenylpropanoid pathway, ensuring cell membrane integrity under HT. The relationship between SA signalling and plant heat tolerance was validated using a maize SA synthesis-synthetic mutant.

The thickness of the pericarp is a complex characteristic that determines sweet corn’s palatability. However, the molecular mechanisms in forming pericarp thickness differences have not been clarified. In this study, we conducted transcriptomics, miRNA analysis, and metabolomics to explore the underlying molecular mechanisms. Scanning electron microscopy (SEM) revealed that the disparity in pericarp thickness is primarily due to variations in the number of cell layers. Our combined multi-omics analysis discovered 6,054 differentially expressed genes (DEGs), 73 differentially expressed miRNAs, 113 differentially accumulated metabolites (DAMs), and several key miRNAs, such as zma-miR164, zma-miR166, zma-miR827, and zma-miR171b were identified, which modulate the expression of different transcription factors and regulate the signal transduction of various plant hormones, thereby influencing pericarp thickness. Additionally, our integrated transcriptomic and metabolomic analysis revealed that genes and metabolites involved in plant hormone signal transduction and phenylpropanoids biosynthesis pathway play a significant role in regulating pericarp growth and development. Furthermore, we observed that in the thick pericarp line (M08), the content of cytokinins was significantly reduced, while phenylpropanoid compounds such as 5-O-feruloylquinic acid glucoside, berberine, scopoletin, sinapic alcohol, sinapic acid and 3-O-feruloylquinic acid glucoside accumulated considerably. These findings provide valuable theoretical support and genetic resources.

Waxy corn and sweet corn are two major types of fresh-eating corn. Each has significant market value due to its unique sensory and nutritional profiles. Developing a variety that combines both traits would meet growing consumer demand and create new market opportunities. From a fast neutron-mutagenized population of the waxy corn inbred line HB522, we identified a mutant, wx-sweet , whose kernels exhibit both waxy and sweet properties at the filling stage. Using bulked segregant analysis (BSA) and fine mapping, we localized the causal locus to SHRUNKEN1 ( Sh1 ) on chromosome 9, which was confirmed by an allelic test with a known Mu-insertion mutant. PCR and sequencing indicated a putative large structural variation in the second and third exons of Sh1 in wx-sweet , likely disrupting the reading frame. This novel sh1 allele significantly reduced sucrose synthase activity. The sh1 and waxy1 mutant genes act synergistically to remodel carbohydrate metabolism in wx-sweet endosperms. This remodeling, revealed by integrated transcriptomic and metabolomic analyses, drives transcriptional reprogramming and restructures metabolic flux. These changes thereby enhance sucrose and raffinose accumulation, which underlies the unique waxy-sweet texture in fresh-eating maize endosperm. In summary, our work not provides valuable genetic resources for fresh-eating corn breeding, but also elucidates, for the first time, the molecular mechanism underlying the synergistic formation of waxy and sweet texture. Key message The novel allele of Sh1 acts synergistically with waxy1 to regulate carbohydrate metabolism, which elucidates the molecular mechanism for the unique waxy-sweet texture in fresh-eating corn endosperm. Our work provides new strategies for sweet-waxy maize breeding. ### Competing Interest Statement The authors have declared no competing interest. Agricultural Science and Technology Independent Innovation Fund Project of Jiangsu Province, CX [24]3090 “JBGS” Project of Seed Industry Revitalization in Jiangsu Province, JBGS [2021]012 National Natural Science Foundation of China, 32372101

High temperature (HT) during the grain-filling stage has become an important factor restricting endosperm development and yield formation in maize. Saicylic acid (SA) is an efficient plant-protective hormone, but its specific function and molecular mechanism regulating the heat tolerance of maize grains have not been reported. In this study, two waxy maize varieties cultivated in pots were used as research materials, and exogenous SA and HT were applied at the initial grain-filling stage. Compared with HT, the application of SA prolonged grain-filling duration and increased grain numbers per panicle, thereby improving the grain weight and yield. SA enhanced the ploidy level and promoted the proliferation of endosperm cells under HT. SA promoted the biosynthesis and accumulation of sucrose and starch in endosperm under HT by regulating their metabolism. SA stabilized the balance of endogenous hormones in heat-tolerant variety, and activated the plant hormone signal transduction pathway. SA triggered alpha-linolenic acid metabolism and jasmonic acid signaling pathways of heat-tolerant variety. Furthermore, SA adjusted the phenylpropanoid and flavonoid biosynthesis pathways of heat-sensitive variety. In conclusion, the physiological, biochemical, transcription profile, and metabolite level changes induced by SA treatment form the basis for the enhancement of heat tolerance of maize endosperm.

During the 2019 and 2020 growth season, Sukenuo 1501, Sukenuo 12, Sukehuanuo 2008, Sukenuo11, Suyunuo 5, and Wannuo 2000 were chosen as experimental materials to analyze the difference of grain yield and grain filling characteristics in Southern Area, which would support breeding high-yield and high-quality waxy maize variety. The results showed that grain yield and yield components were similar in two years. Grain number and grain weight per ear were higher in higher-yield varieties（Sukenuo 12, Sukenuo 1501, Wannuo 2000 and Sukehuanuo 2008） than those in lower-yield varieties（Suyunuo 5 and Sukenuo 11）. The grain yield was significantly positively correlated with ear length, ear grains and 100-kernel fresh weight. The 100-kernel fresh weight was significantly positively correlated with the maximum filling rate and average filling rate. The number of grains per ear was correlated with the effective grain filling period, maximum grain filling rate and the growth at maximum grain filling rate. Therefore, the selection of higher filling rate and growth at maximum filling rate could be used for higher-yield varieties of waxy maize.

Maize rough dwarf disease (MRDD), caused by maize rough dwarf virus (MRDV) or rice black-streaked dwarf virus (RBSDV), seriously threatens worldwide production of all major cereal crops, including maize, rice, wheat and barley. Here we report fine mapping and cloning of a previously reported major quantitative trait locus (QTL) ( qMrdd2 ) for RBSDV resistance in maize. Subsequently, we show that qMrdd2 encodes a G2-like transcription factor named ZmGLK36 that promotes resistance to RBSDV by enhancing jasmonic acid (JA) biosynthesis and JA-mediated defence response. We identify a 26-bp indel located in the 5′ UTR of ZmGLK36 that contributes to differential expression and resistance to RBSDV in maize inbred lines. Moreover, we show that ZmDBF2, an AP2/EREBP family transcription factor, directly binds to the 26-bp indel and represses ZmGLK36 expression. We further demonstrate that ZmGLK36 plays a conserved role in conferring resistance to RBSDV in rice and wheat using transgenic or marker-assisted breeding approaches. Our results provide insights into the molecular mechanisms of RBSDV resistance and effective strategies to breed RBSDV-resistant cereal crops.

为筛选适合淮北区夏玉米机械粒收新品种,促进机械粒收技术在该区域的推广应用,加快优良品种推广,于2020年选取淮北不同生态条件的5个试验点,对9个夏玉米区审定的品种开展了玉米机械粒收品种筛选试验.对不同品种的生育期、籽粒含水率、籽粒破碎率、产量、倒伏倒折率和茎腐病发病率等进行测定和分析,以参试品种平均产量和收获期平均籽粒破碎率为指标,采用双向平均作图法,综合各品种丰产性、稳产性和区域适应性,初步筛选出丰产性和稳产性好、在淮北区适应性广、耐密植、抗倒性好且籽粒脱水快的品种苏科玉206,可推荐为淮北区适宜机械粒收备选品种.

苏科糯12是江苏省农业科学院粮食作物研究所以自育自交系W13881XJSW12475组配育成的半紧凑型彩色糯玉米品种,2018年通过江苏省审定.该品种早熟,春播出苗到采收约87 d;果穗中等,食味品质优、糯性好;籽粒红白相间,色泽好,适合采用鲜穗上市和加工;抗病性好,适应性广,适宜在江苏及周边地区种植.本文作者简要介绍了该品种的特征特性,总结了该品种在苏北地区的高产制种技术,以期为鲜食玉米品种实现本地高产制种提供参考.

为了明确江苏沿海地区大豆玉米带状复合种植模式下玉米适宜的种植密度,以'苏科玉1705'和'江玉877'为试验材料,设置了 3个种植密度(60000、67500、75000株/hm2),研究了种植密度对玉米植株生长和产量的影响.结果表明,种植密度对2个玉米品种的株高、穗位高、茎粗、叶片性状和产量性状的影响基本一致.随种植密度的增加,玉米株高、穗位高、倒伏率、倒折率、空杆率逐渐提高,茎粗、叶长、叶宽、叶片夹角和产量逐渐降低;在60000株/hm2密度下'苏科玉1705'和'江玉877'产量最高分别为:6299、5431 kg/hm2,且倒伏、倒折、空杆率最低;在67500、75000株/hm2密度下,2个品种倒伏、倒折率提高,生产风险加大.品种间比较,相同种植密度下'苏科玉1705'的叶宽、叶面积、叶片夹角、倒折率、秃尖长较低,穗长和粒重较高,产量显著高于'江玉877'.综上,在江苏沿海地区,带状复合种植模式下'苏科玉1705'和'江玉877'在60000株/hm2种植密度下可实现高产.

Maize yield is mostly determined by its grain size. Although numerous quantitative trait loci (QTL) have been identified for kernel-related traits, the application of these QTL in breeding programs has been strongly hindered because the populations used for QTL mapping are often different from breeding populations. However, the effect of genetic background on the efficiency of QTL and the accuracy of trait genomic prediction has not been fully studied. Here, we used a set of reciprocal introgression lines (ILs) derived from 417F × 517F to evaluate how genetic background affects the detection of QTLassociated with kernel shape traits. A total of 51 QTL for kernel size were identified by chromosome segment lines (CSL) and genome-wide association studies (GWAS) methods. These were subsequently clustered into 13 common QTL based on their physical position, including 7 genetic-background-independent and 6 genetic-background-dependent QTL, respectively. Additionally, different digenic epistatic marker pairs were identified in the 417F and 517F ILs. Therefore, our results demonstrated that genetic background strongly affected not only the kernel size QTL mapping via CSL and GWAS but also the genomic prediction accuracy and epistatic detection, thereby enhancing our understanding of how genetic background affects the genetic dissection of grain size-related traits.

Brassinosteroid (BR) has been indicated to induce the production of hydrogen peroxide (H2O2) in plants in response to various environmental stimuli. However, it remains largely unknown how BR induces H2O2 production. In this study, we found that BR treatment significantly raised the kinase activity of maize (Zea mays L.) brassinosteroid-signaling kinase 1 (ZmBSK1) using the immunoprecipitation kinase assay. ZmBSK1 could modulate the gene expressions and activities of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (EC 1.6.3.1) to modulate BR-induced H2O2 production. BR could enhance the interaction between ZmBSK1 and maize calcium/calmodulin-dependent protein kinase (ZmCCaMK), a previously identified substrate of ZmBSK1. The BR-induced phosphorylation and kinase activity of ZmCCaMK are dependent on ZmBSK1. Moreover, we showed that ZmBSK1 regulated the NADPH oxidase gene expression and activity via directly phosphorylating ZmCCaMK. Genetic analysis suggested that ZmBSK1-ZmCCaMK module strengthened plant tolerance to oxidative stress induced by exogenous application of H2O2 through improving the activities of antioxidant defense enzyme and alleviating the malondialdehyde (MDA) accumulation and electrolyte leakage rate. In conclusion, these findings provide the new insights of ZmBSK1 functioning in BR-induced H2O2 production and the theoretical supports for breeding stress-tolerant crops.

研究淹水对玉米物质积累和光合能力的影响及有效缓解措施,以期为玉米抗逆高产栽培提供依据.以两个耐涝性不同的玉米自交系为试验材料,研究了外源亚精胺对淹水条件下植株物质积累、叶面积、叶绿素含量、净光合速率和叶绿素荧光特性等指标的影响.结果表明,与对照相比,淹水处理显著降低玉米地下部干重、地上部干重、单株干重、相对干物质积累速率和叶面积;随淹水处理天数增加,叶片叶绿素含量、净光合速率和实际光化学效率逐渐降低,且敏感型Su95-1各指标降幅最大.淹水条件下外施亚精胺处理植株,干物质积累量和光合指标较对照显著降低,但较淹水处理有不同程度地提高,且Su95-1增幅更大.综上,在淹水条件下,外施亚精胺能提高叶片的光合能力并提高植株耐涝性,最终增加干物质积累.

Salinity has become a crucial environmental factor seriously restricting maize (Zea mays L.) growth, development and productivity. However, how plants respond to salt stress is still poorly understood. In this study, we report that a maize brassinosteroid-signaling kinase gene ZmBSK1 plays a significant role in salt stress response. Expression pattern analysis revealed that the transcript level of ZmBSK1 was upregulated by NaCl treatment both in maize leaves, roots, and stems. Phenotypic and physiological analysis showed that overexpression of ZmBSK1 in maize improved salt tolerance by reducing the malondialdehyde (MDA) content, the percentage of electrolyte leakage, O-2(-) and H2O2 accumulation under salt stress, relying on the increases of antioxidant defense enzyme activities and proline content. qRT-PCR analysis showed that overexpression of ZmBSK1 also positively modulated the expression levels of reactive oxygen species (ROS)-scavenging and proline biosynthesis-related genes under salt stress. Moreover, immunoprecipitation-mass spectrometry (IP-MS) assay and firefly luciferase complementation imaging (LCI) assay showed that ZmBSK1 could associate with heat shock protein ZmHSP8 and 14-3-3-like protein ZmGF14-6, and their gene expression levels could be significantly induced by NaCl treatment in different maize tissues. Our findings unravel the new function of ZmBSK1 in salt stress response, which provides the theoretical bases for the improvement of maize salt resistance.

本研究以2018—2019年国家糯玉米区域试验结果为依据,采用高稳系数法和变异系数法对苏科糯1701的丰产性和稳产性进行分析,采用通径分析法对其产量构成因素进行分析.结果表明,苏科糯1701鲜穗产量平均值为13853 kg·hm-2,较对照苏玉糯5号增产2163 kg·hm-2;高稳系数和变异系数平均值分别为8.5％和15.2％,具有高产稳产的特性.通径分析结果表明,苏科糯1701产量构成因素对产量的相对重要性依次为穗行数、百粒鲜重、鲜出籽率、穗长、秃尖长.苏科糯1701生产过程中要统筹好田间管理,促进果穗长、穗行多、增加百粒重、提高结实率,以实现品种产量潜力的充分发挥.

苏科糯1701是江苏省农业科学院粮食作物研究所与句容苏科鲜食玉米研究有限公司合作,以自交系JSW12471为母本,自交系JSW15180为父本杂交育成的彩色鲜食糯玉米杂交种,2020年通过国家农作物品种审定委员会审定.该品种食味品质优良,丰产稳产性好,抗病性强,适宜在南方(东南)鲜食糯玉米类型区推广应用.介绍苏科糯1701的选育过程、生产表现、特征特性及高产栽培技术.

The establishment of female inflorescence morphology is of great significance to the formation of final maize yield. defective ear1 (dea1) is a novel maize mutant with developmental defect of female inflorescence caused by natural variation. Morphological analysis revealed that the mutant dea1 was characterized as a “scar-like” crack on the adaxial side of the top of the ear, accounting for 28.6-100.0% of the ear length, with an average of 32.4%. The results of scanning electron microscope showed that there was collapse in the formation of paired spikelet primordium at the base of the axillary meristem. Most of investigated botanical and agronomical traits of dea1 were lower than those of wild type, except for ear length and hundred grain weight. The grain yield per ear of mutant dea1 was 35.93% lower than that of wild type, and the width of mutation crack contributed the most to the yield loss per ear. The identification of the mutant dea1 and the characteristically phenotypic analysis provide a theoretical basis for the study of the molecular regulation mechanism of ear development and the application of high-yield breeding in maize.The establishment of female inflorescence morphology is of great significance to the formation of final maize yield. defective ear1 (dea1) is a novel maize mutant with developmental defect of female inflorescence caused by natural variation. Morphological analysis revealed that the mutant dea1 was characterized as a “scar-like” crack on the adaxial side of the top of the ear, accounting for 28.6-100.0% of the ear length, with an average of 32.4%. The results of scanning electron microscope showed that there was collapse in the formation of paired spikelet primordium at the base of the axillary meristem. Most of investigated botanical and agronomical traits of dea1 were lower than those of wild type, except for ear length and hundred grain weight. The grain yield per ear of mutant dea1 was 35.93% lower than that of wild type, and the width of mutation crack contributed the most to the yield loss per ear. The identification of the mutant dea1 and the characteristically phenotypic analysis provide a theoretical basis for the study of the molecular regulation mechanism of ear development and the application of high-yield breeding in maize.

The quality characteristics of 17 fresh eating waxy corn varieties were studied based on their quality and structure characteristics. The former included the content of moisture, starch, amylose and amylopectin, total sugar, dietary fiber, crude protein and crude fat, while the latter included the value of hardness, elasticity, cohesion, adhesiveness and chewiness. In order to screen out the core evaluation index, correlation analysis and principal component analysis were applied in this process. The entropy weight method was to assign weight to each index. And the grey correlation degree method was to comprehensively evaluate the quality. The results showed that there were differences in quality of different fresh-edible waxy corns. The texture properties had a good correlation with amylose and amylopectin. Four core evaluation indicators of fresh waxy corn were determined by principal component analysis; amylopectin, total sugar, moisture and crude fat. The weight value of amylopectin was the highest by the entropy method. The varieties with better comprehensive quality were ‘Wannuo2000’, ‘Sukenuo1702’ and ‘Sukenuo1505’ with the grey correlation analysis. The results would provide theoretical support for the evaluation of comprehensive quality and screening of fresh waxy corn variety.