Extraction, purification, characteristics, bioactivities, prospects, and toxicity of Lilium spp. polysaccharides.

The genus Lilium has been widely used worldwide as a food and medicinal ingredient in East Asia for over 2000 years due to its higher nutritional and medicinal value. Polysaccharide is the most important bioactive ingredient in Lilium spp. and has various health benefits. Recently, Lilium spp. polysaccharides (LSPs) have attracted significant attention from industries and researchers due to their various biological properties, such as antioxidant, immunomodulatory, antitumor, antibacterial, hypoglycaemic, and anti-radiation. However, the development and utilization of LSP-based functional biomaterials and medicines are limited by a lack of comprehensive understanding regarding the structure-activity relationships (SARs), industrial applications, and safety of LSPs. This review provides an inclusive overview of the extraction, purification, structural features, bioactivities, and mechanisms of LSPs. SARs, applications, toxicities, and influences of structural modifications on bioactivities are also highlighted, and the potential development and future study direction are scrutinized. This article aims to offer a complete understanding of LSPs and provide a foundation for further research and application of LSPs as therapeutic agents and multifunctional biomaterials.

Preparation, structural characterization, bioactivities, and applications of Crataegus spp. polysaccharides: A review.

Crataegus, is a genus within the Rosaceae family. It is recognized as a valuable plant with both medicinal and edible qualities, earning it the epithet of the "nutritious fruit" owing to its abundant bioactive compounds. Polysaccharides are carbohydrate polymers linked by glycosidic bonds, one of the crucial bioactive ingredients of Crataegus spp. Recently, Crataegus spp. polysaccharides (CPs) have garnered considerable attention due to their diverse range of bioactivities, including prebiotic, hypolipidemic, anticancer, antibacterial, antioxidant, and immunobiological properties. Herein, we provide a comprehensive overview of recent research on CPs. The analysis revealed that CPs exhibited a broad molecular weight distribution, ranging from 5.70 Da to 4.76 × 108 Da, and are composed of various monosaccharide constituents such as mannose, rhamnose, and arabinose. Structure-activity relationships demonstrated that the biological function of CPs is closely associated with their molecular weight, galacturonic acid content, and chemical modifications. Additionally, CPs have excellent bioavailability, biocompatibility, and biodegradability, which make them promising candidates for applications in the food, medicine, and cosmetic industries. The article also scrutinized the potential development and future research directions of CPs. Overall, this article provides comprehensive knowledge and underpinnings of CPs for future research and development as therapeutic agents and multifunctional food additives.

Geastrumsuae sp. nov. (Geastraceae, Basidiomycota) a new species from Yunnan Province, China.

Background: Geastrum is the largest genus of Geastraceae and is widely distributed all over the world. Four specimens which belong to Geastrum were collected during our scientific expedition to Cangshan Mountain, Yunnan, China. Based on morphological characteristics and phylogenetic analysis, a new species was introduced. New information: Geastrumsuae is characterised by its large basidiomata (height 35-70 mm, diameter 18-37 mm) with long stipe (height 10-45 mm), smooth pink exoperidium and sessile globose endoperidial body. Phylogenetic analysis has been carried out, based on the internal transcribed spacer (ITS) and large subunit ribosomal ribonucleic acid (nrLSU) sequence data. The illustration and description for the new taxa are provided.

Foliar Application of Spermidine Alleviates Waterlogging-Induced Damages to Maize Seedlings by Enhancing Antioxidative Capacity, Modulating Polyamines and Ethylene Biosynthesis.

Waterlogging is a major threat to maize production worldwide. The exogenous application of spermidine is well known to enhance plant tolerance to abiotic stresses. The role of exogenous spermidine application in waterlogging tolerance in maize was investigated in this study. Two maize varieties (a waterlogging-tolerant variety: Xundan 20 (XD20) and a waterlogging-sensitive variety: Denghai 662 (DH662)) were subjected to waterlogging stress at the seedling stage, and then foliar spraying of 0.75 mM spermidine or purified water. Findings demonstrated lower chlorophyll content, reduced growth indices, considerable increase in superoxide anion (O2-) generation rate, and H2O2/malondialdehyde accumulation in the two maize varieties under waterlogging stress compared to the control treatment. However, the tolerance variety performed better than the sensitive one. Foliar application of spermidine significantly increased antioxidant enzyme activities under waterlogging stress. In addition, the application of spermidine increased polyamine levels and led to the reduction of ethylene levels under waterlogging. Consequences of spermidine application were most apparent for the waterlogging-sensitive cultivar DH662 under waterlogging than the waterlogging-tolerant variety XD20.

Ovary Abortion Induced by Combined Waterlogging and Shading Stress at the Flowering Stage Involves Amino Acids and Flavonoid Metabolism in Maize.

Maize (Zea mays L.) crops on the North China Plain are often subject to continuous overcast rain at the flowering stage. This causes waterlogging and shading stresses simultaneously and leads to huge yield losses, but the causes of these yield losses remain largely unknown. To explore the factors contributing to yield loss caused by combined waterlogging and shading stress at the flowering stage, we performed phenotypic, physiological, and quasi-targeted metabolomics analyses of maize plants subjected to waterlogging, shading, and combined waterlogging and shading (WS) treatments. Analyses of phenotypic and physiological indexes showed that, compared with waterlogging or shading alone, WS resulted in lower source strength, more severe inhibition of ovary and silk growth at the ear tip, a reduced number of emerged silks, and a higher rate of ovary abortion. Changes in carbon content and enzyme activity could not explain the ovary abortion in our study. Metabolomic analyses showed that the events occurred in ovaries and silks were closely related to abortion, WS forced the ovary to allocate more resources to the synthesis of amino acids involved in the stress response, inhibited the energy metabolism, glutathione metabolism and methionine salvage pathway, and overaccumulation of H2O2. In silks, WS led to lower accumulation levels of specific flavonoid metabolites with antioxidant capacity, and to over accumulation of H2O2. Thus, compared with each single stress, WS more seriously disrupted the normal metabolic process, and resulted more serious oxidative stress in ovaries and silks. Amino acids involved in the stress response in ovaries and specific flavonoid metabolites with antioxidant capacity in silks play important roles during ovary abortion. These results identify novel traits for selection in breeding programs and targets for genome editing to increase maize yield under WS stress.

The calcium-dependent protein kinase ZmCDPK7 functions in heat-stress tolerance in maize.

Global warming poses a serious threat to crops. Calcium-dependent protein kinases (CDPKs)/CPKs play vital roles in plant stress responses, but their exact roles in plant thermotolerance remains elusive. Here, we explored the roles of heat-induced ZmCDPK7 in thermotolerance in maize. ZmCDPK7-overexpressing maize plants displayed higher thermotolerance, photosynthetic rates, and antioxidant enzyme activity but lower H2 O2 and malondialdehyde (MDA) contents than wild-type plants under heat stress. ZmCDPK7-knockdown plants displayed the opposite patterns. ZmCDPK7 is attached to the plasma membrane but can translocate to the cytosol under heat stress. ZmCDPK7 interacts with the small heat shock protein sHSP17.4, phosphorylates sHSP17.4 at Ser-44 and the respiratory burst oxidase homolog RBOHB at Ser-99, and upregulates their expression. Site-directed mutagenesis of sHSP17.4 to generate a Ser-44-Ala substitution reduced ZmCDPK7's enhancement of catalase activity but enhanced ZmCDPK7's suppression of MDA accumulation in heat-stressed maize protoplasts. sHSP17.4, ZmCDPK7, and RBOHB were less strongly upregulated in response to heat stress in the abscisic acid-deficient mutant vp5 versus the wild type. Pretreatment with an RBOH inhibitor suppressed sHSP17.4 and ZmCDPK7 expression. Therefore, abscisic acid-induced ZmCDPK7 functions both upstream and downstream of RBOH and participates in thermotolerance in maize by mediating the phosphorylation of sHSP17.4, which might be essential for its chaperone function.

The miRNA-Mediated Post-Transcriptional Regulation of Maize in Response to High Temperature.

High temperature (HT) has recently become one of the most important abiotic stresses restricting crop production worldwide. MicroRNAs (miRNAs) are important regulators in plant development and stress responses. However, knowledge of miRNAs of maize in response to HT is limited. In this study, we simultaneously adopted miRNA sequencing and transcriptome profiling to analyze the differential expression of miRNAs and mRNAs in maize during exposure to HT stress. Our analysis revealed 61 known miRNAs belonging to 26 miRNA families and 42 novel miRNAs showing significant differential expression, with the majority being downregulated. Meanwhile, the expression of 5450 mRNAs was significantly altered in the same stressed tissues. Differentially expressed transcripts were most significantly associated with response to stress, photosynthesis, biosynthesis of secondary metabolites, and signal transduction pathways. In addition, we discovered 129 miRNA­mRNA pairs that were regulated antagonistically, and further depiction of the targeted mRNAs indicated that several transcription factors, protein kinases, and receptor-like-protein-related transmembrane transport and signaling transduction were profoundly affected. This study has identified potential key regulators of HT-stress response in maize and the subset of genes that are likely to be post-transcriptionally regulated by miRNAs under HT stress.

Development of Incompletely Fused Carpels in Maize Ovary Revealed by miRNA, Target Gene and Phytohormone Analysis.

Although the molecular basis of carpel fusion in maize ovary development remains largely unknown, increasing evidence suggests a critical role of microRNAs (miRNAs). In this study, a combination of miRNA sequencing, degradome and physiological analyses was used to characterize carpel fusion development in maize ovaries showing incompletely (IFC) and completely fused carpels (CFC). A total of 162 known miRNAs distributed across 33 families were identified, of which 20 were differentially expressed. In addition, 53 miRNA candidates were identified, of which 10 were differentially expressed in the IFC and CFC ovaries. In degradome analysis, a total of 113 and 11 target genes were predicted for the known and novel miRNAs, respectively. Moreover, 24 (60%) target genes of the differentially expressed known miRNAs were found to code transcription factors, including auxin response factor (ARF), TB1-CYC-PCFs (TCP), APETALA2 (AP2), growth regulating factor (GRF), MYB, NAC, and NF-YA, all of which have been shown to play a role in carpel fusion development. Correlation analysis of these differentially expressed known miRNAs and their targets with phytohormone signals revealed significant correlations with at least one phytohormone signal, the main regulator of carpel fusion development. These results suggest that incomplete carpel fusion is partly the result of differential expression of certain miRNAs and their targets. Overall, these findings improve our knowledge of the effect of miRNA regulation on target expression, providing a useful resource for further analysis of the interactions between miRNAs, target genes and phytohormones during carpel fusion development in maize.

The Difference of Physiological and Proteomic Changes in Maize Leaves Adaptation to Drought, Heat, and Combined Both Stresses.

At the eight-leaf stage, maize is highly sensitive to stresses such as drought, heat, and their combination, which greatly affect its yield. At present, few studies have analyzed maize response to combined drought and heat stress at the eight-leaf stage. In this study, we measured certain physical parameters of maize at the eight-leaf stage when it was exposed to drought, heat, and their combination. The results showed an increase in the content of H2O2 and malondialdehyde (MDA), and in the enzyme activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR), but a decrease in the quantum efficiency of photosystem II (ΦPSII). The most obvious increase or decrease in physical parameters was found under the combined stress condition. Moreover, to identify proteins differentially regulated by the three stress conditions at the eight-leaf stage, total proteins from the maize leaves were identified and quantified using multiplex iTRAQ-based quantitative proteomic and LC-MS/MS methods. In summary, the expression levels of 135, 65, and 201 proteins were significantly changed under the heat, drought and combined stress conditions, respectively. Of the 135, 65, and 201 differentially expressed proteins, 61, 28, and 16 responded exclusively to drought stress, heat stress, and combined stress, respectively. Bioinformatics analysis implied that chaperone proteins and proteases play important roles in the adaptive response of maize to heat stress and combined stress, and that the leaf senescence promoted by ethylene-responsive protein and ripening-related protein may play active roles in maize tolerance to combined drought and heat stress. The signaling pathways related to differentially expressed proteins were obviously different under all three stress conditions. Thus, the functional characterization of these differentially expressed proteins will be helpful for discovering new targets to enhance maize tolerance to stress.

Differential morphology and transcriptome profile between the incompletely fused carpels ovary and its wild-type in maize.

We have isolated a new mutation in maize, incompletely fused carpels (ifc), which results in an open stylar canal on the ovary and an incomplete pericarp at the top of the kernel. The maize ovary derives from the fusion of three carpels; however, the molecular networks regulating maize carpel fusion remain largely unclear. In this study, RNA sequencing (RNA-seq) was performed on wild-type (WT) and ifc ovaries that were collected after carpel fusion defects could be morphologically distinguished. In total, 877 differentially expressed genes were identified. Functional analysis revealed overexpression of genes related to "DNA binding", "transcription regulation", "hormones", and "stress responses". Among the 88 differentially expressed transcription factor (TF) genes, five showed a high degree of conservation (77.7-88.0% amino acid identity) of their conserved domains with genes associated with carpel fusion deficiency in Arabidopsis thaliana, suggesting that these five genes might control carpel fusion in maize. In addition, 30 genes encoding components of hormone synthesis and signaling pathways were differentially expressed between ifc and WT ovaries, indicating complex hormonal regulation during carpel fusion. These results help elucidate the underlying mechanisms that regulate carpel fusion, supporting the functional analysis of genes involved in producing this phenotype.

[Effects of tillage and straw returning on microorganism quantity, enzyme activities in soils and grain yield].

A two-year field study with split plot design was conducted to investigate the effects of different soil tillage (conventional tillage, CT; deep tillage, DT; subsoil tillage, ST) and straw returning (all straw retention, AS; no straw returning, NS) on microorganism quantity, enzyme activities in soil and grain yield. The results showed that, deep or subsoil tillage and straw returning not only reduced the soil bulk density and promoted the content of organic carbon in soil, but increased the soil microbial quantity, soil enzyme activities and grain yield. Furthermore, such influences in maize season were greater than that in wheat season. Compared with CT+NS, DT+AS and ST+AS decreased the soil bulk density at 20-30 cm depth by 8.5% and 6.6%, increased the content of soil organic carbon by 14.8% and 12.4%, increased the microorganism quantity by 45.9% and 33.9%, increased the soil enzyme activities by 34.1% and 25.5%, increased the grain yield by 18.0% and 19.3%, respectively. No significant difference was observed between DT+AS and ST+AS. We concluded that retaining crop residue and deep or subsoil tillage improved soil microorganism quantity, enzyme activities and crop yield.

Quantitative iTRAQ-based proteomic analysis of phosphoproteins and ABA-regulated phosphoproteins in maize leaves under osmotic stress.

Abscisic acid (ABA) regulates various developmental processes and stress responses in plants. Protein phosphorylation/dephosphorylation is a central post-translational modification (PTM) in ABA signaling. However, the phosphoproteins regulated by ABA under osmotic stress remain unknown in maize. In this study, maize mutant vp5 (deficient in ABA biosynthesis) and wild-type Vp5 were used to identify leaf phosphoproteins regulated by ABA under osmotic stress. Up to 4052 phosphopeptides, corresponding to 3017 phosphoproteins, were identified by Multiplex run iTRAQ-based quantitative proteomic and LC-MS/MS methods. The 4052 phosphopeptides contained 5723 non-redundant phosphosites; 512 phosphopeptides (379 in Vp5, 133 in vp5) displayed at least a 1.5-fold change of phosphorylation level under osmotic stress, of which 40 shared common in both genotypes and were differentially regulated by ABA. Comparing the signaling pathways involved in vp5 response to osmotic stress and those that in Vp5, indicated that ABA played a vital role in regulating these pathways related to mRNA synthesis, protein synthesis and photosynthesis. Our results provide a comprehensive dataset of phosphopeptides and phosphorylation sites regulated by ABA in maize adaptation to osmotic stress. This will be helpful to elucidate the ABA-mediate mechanism of maize endurance to drought by triggering phosphorylation or dephosphorylation cascades.

In situ nitrogen mineralization, nitrification, and ammonia volatilization in maize field fertilized with urea in Huanghuaihai region of northern China.

Nitrogen (N) fertilization potentially affects soil N mineralization and leaching, and can enhance NH3 volatilization, thus impacting crop production. A fertilizer experiment with five levels of N addition (0, 79, 147, 215 and 375 kg N ha(-1)) was performed in 2009 and 2010 in a maize field in Huanghuaihai region, China, where > 300 kg N ha(-1) has been routinely applied to soil during maize growth period of 120 days. Responses of net N mineralization, inorganic N flux (0-10 cm), NH3 volatilization, and maize yield to N fertilization were measured. During the growth period, net N mineralization and nitrification varied seasonally, with higher rates occurring in August and coinciding with the R1 stage of maize growth. Soil NO3(-)-N contributed to more than 60% of inorganic N flux during maize growth. Cumulative NH3 volatilization increased with N additions, with total NH3 volatilization during maize growth accounting for about 4% of added N. Relative to the control, mean maize yield in the fertilizer treatments increased by 17% and 20% in 2009 and 2010, respectively. However, grain yield, aboveground biomass, and plant N accumulation did not increase with added N at levels > 215 kg N ha(-1). These results suggest that the current N rate of 300 kg N ha(-1) is not only excessive, but also reduces fertilizer efficacy and may contribute to environmental problems such as global warming and eutrophication of ground water and streams.

Spatial variation in carbon and nitrogen in cultivated soils in Henan Province, China: potential effect on crop yield.

Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0-40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and N concentrations were 14.9 g kg(-1) and 1.37 g kg(-1), respectively, whereas soil C and N stores were 4.1 kg m(-2) and 0.4 kg m(-2), respectively. Total crop production of each county was significantly, positively related to SOC, TSN, soil C and N store, and soil C and N stock. Soil C and N were positively correlated with soil bulk density but negatively correlated with soil porosity. These results indicate that variations in soil C could regulate crop yield in intensive agricultural systems, and that spatial patterns of C and N levels in soils may be regulated by both climatic factors and agro-ecosystem management. When developing suitable management programs, the importance of soil C and N stores and their effects on crop yield should be considered.

Effects of deep tillage and straw returning on soil microorganism and enzyme activities.

Two field experiments were conducted for two years with the aim of studying the effects of deep tillage and straw returning on soil microorganism and enzyme activity in clay and loam soil. Three treatments, (1) conventional tillage (CT), shallow tillage and straw returning; (2) deep tillage (DT), deep tillage and straw returning; and (3) deep tillage with no straw returning (DNT), were carried out in clay and loam soil. The results showed that deep tillage and straw returning increased the abundance of soil microorganism and most enzyme activities. Deep tillage was more effective for increasing enzyme activities in clay, while straw returning was more effective in loam. Soil microorganism abundance and most enzyme activities decreased with the increase of soil depth. Deep tillage mainly affected soil enzyme activities in loam at the soil depth of 20-30 cm and in clay at the depth of 0-40 cm. Straw returning mainly affected soil microorganism and enzyme activities at the depths of 0-30 cm and 0-40 cm, respectively.

Molecular characterization of glutaredoxin 2 from Ostrinia furnacalis.

Glutaredoxins (GRXs) play very important roles in maintaining intracellular redox homeostasis. In the present study, the full-length cDNA sequence encoding GRX2, named OfurGRX2 (GenBank accession no. GU393246), was obtained from Ostrinia furnacalis, using reverse transcription polymerase chain reaction and rapid amplification of cDNA ends. Sequence analysis revealed that the open reading frame of OfurGRX2 consists of 351 nucleotides encoding 116 amino acid residues with a predicted molecular weight of 12.6 kDa. Homolog research revealed that OfurGRX2 shares a common active site, CPYC/CPFC, with other insect counterparts. Expression profiles revealed that OfurGRX2 is a ubiquitous gene expressed in insect heads, fat bodies, epidermises, mid guts and muscles. The OfurGRX2 transcript peaked in 36-h larvae of 4th instars, and then suddenly declined in the molting stage. Hormone treatment experiments revealed that 20-hydroxyecodyson (20e) significantly induces the expression of the OfurGRX2 transcript, whereas juvenile hormone (JH) counteracts 20e effects. Adverse stress factors (including starvation, ultraviolet light, mechanical injury, Escherichia coli exposure, and high and low temperatures) dramatically induced OfurGRXGRX2 transcript expression, which confirmed for the first time that GRX2 play important roles in insecta during exposure to adverse environments.

Abscisic acid refines the synthesis of chloroplast proteins in maize (Zea mays) in response to drought and light.

To better understand abscisic acid (ABA) regulation of the synthesis of chloroplast proteins in maize (Zea mays L.) in response to drought and light, we compared leaf proteome differences between maize ABA-deficient mutant vp5 and corresponding wild-type Vp5 green and etiolated seedlings exposed to drought stress. Proteins extracted from the leaves of Vp5 and vp5 seedlings were used for two-dimensional electrophoresis (2-DE) and subsequent matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). After Coomassie brilliant blue staining, approximately 450 protein spots were reproducibly detected on 2-DE gels. A total of 36 differentially expressed protein spots in response to drought and light were identified using MALDI-TOF MS and their subcellular localization was determined based on the annotation of reviewed accession in UniProt Knowledgebase and the software prediction. As a result, corresponding 13 proteins of the 24 differentially expressed protein spots were definitely localized in chloroplasts and their expression was in an ABA-dependent way, including 6 up-regulated by both drought and light, 5 up-regulated by drought but down-regulated by light, 5 up-regulated by light but down-regulated by drought; 5 proteins down-regulated by drought were mainly those involved in photosynthesis and ATP synthesis. Thus, the results in the present study supported the vital role of ABA in regulating the synthesis of drought- and/or light-induced proteins in maize chloroplasts and would facilitate the functional characterization of ABA-induced chloroplast proteins in C(4) plants.

QTL analysis of shading sensitive related traits in maize under two shading treatments.

During maize development and reproduction, shading stress is an important abiotic factor influencing grain yield. To elucidate the genetic basis of shading stress in maize, an F(2:3) population derived from two inbred lines, Zhong72 and 502, was used to evaluate the performance of six traits under shading treatment and full-light treatment at two locations. The results showed that shading treatment significantly decreased plant height and ear height, reduced stem diameter, delayed day-to-tassel (DTT) and day-to-silk (DTS), and increased anthesis-silking interval (ASI). Forty-three different QTLs were identified for the six measured traits under shading and full light treatment at two locations, including seven QTL for plant height, nine QTL for ear height, six QTL for stem diameter, seven QTL for day-to-tassel, six QTL for day-to-silk, and eight QTL for ASI. Interestingly, three QTLs, qPH4, qEH4a, and qDTT1b were detected under full sunlight and shading treatment at two locations simultaneously, these QTL could be used for selecting elite hybrids with high tolerance to shading and high plant density. And the two QTL, qPH10 and qDTS1a, were only detected under shading treatment at two locations, should be quit for selecting insensitive inbred line in maize breeding procedure by using MAS method.

[Effects of nitrogen fertilization rate and harvest time on summer maize grain yield and its quality].

In order to approach the optimal nitrogen fertilization rate and suitable harvest time for the high grain yield and quality of summer maize in Huanghe-Haihe Area, a field experiment with five nitrogen fertilization rates (0, 113, 181, 249, and 375 kg N x hm(-2)) and two harvest time (S1: September 23, conventional harvest time for local farmers, and S2: September 29, 6 days delayed) was conducted. The results showed that the kernel number, grain yield, and 1000-grain mass increased with nitrogen fertilization rate, but the differences were not significant. With increasing nitrogen fertilization rate, the protein and lysine contents of the grains increased, while the starch content decreased. After 6 days delayed for harvest, the grain yield, 1000-grain mass, and the starch and lysine contents of the grains increased, but the protein and crude fat contents decreased. Based on the yield level, the optimal nitrogen fertilization rate for the summer maize in Huanghe-Haihe Area was 113-180 kg N x hm(-2), and the suitable harvest time was from September 29 to October 5.

[Shade-tolerance indices of maize: selection and evaluation].

A field experiment was conducted to study the morphological, physiological, and yield traits of 24 maize cultivars under 50% shading. Comparing with the control, 50% shading decreased the plant height, stem diameter, leaf net photosynthetic rate (Pn), specific leaf weight (SLW), aboveground dry matter accumulation, ear length and diameter, axis diameter, and kernels per row. The interval from anthesis to silking (ASI) was prolonged, and the grain yield was decreased significantly. The percent changes of ASI, Pn, SLW, and kernels per row were significantly correlated with aboveground dry matter accumulation and grain yield, being able to be used as the indices to evaluate the maize shade-tolerance in field. Cluster analysis using comprehensive shade-tolerance traits as evaluation parameters indicated that 14 maize cultivars including Zhengdan 958, Xundan 20, and Denghai 602, etc. were of shade-tolerance type, and 10 cultivars (Anyu 12 and Yuyu 22, etc. ) were of shade-sensitive type. It was suggested that adopting the morphological, physiological and yield traits as the indices to evaluate the shade-tolerance of maize would be more objective, simple and practical.