Salt stress imposes a remarkable effect on how plants grow and their productivity levels. Although melatonin is well-known for its capacity to improve seed germination and promote plant growth when plants are exposed to stressful environments, its role in seed priming remains underexplored. This study elucidated how melatonin priming influenced the traditional Chinese medicinal herb Salvia miltiorrhiza's seed germination and seedling growth in the presence of salt stress. The results revealed that 20 mu M melatonin priming enhanced germination energy, germination percentage, and plant biomass; increased root antioxidant enzyme activity; elevated K+ and GA3 levels; and improved the K+/Na+ ratio. Moreover, it upregulated the expression of key genes related to GA biosynthesis (SmKO and SmKAO1) while reducing the levels of MDA, H2O2, ABA, and Na+, as well as the ABA/ GA3 ratio, and downregulated the expression of ABA, H2O2, and tanshinone biosynthesis genes (SmNCED3, SmNCED5, SmRbohD, SmRbohF, SmCYP76AH1, and SmKSL1). Moreover, exogenous ABA increased the levels of both tanshinone and H2O2 in the presence of salt stress, while H2O2 in turn facilitated the accumulation of tanshinone. Overall, melatonin priming effectively enhances seed germination in the context of salt stress and promotes seedling performance by stimulating GA production, inhibiting ABA, and regulating tanshinone accumulation in response to H2O2levels. These results demonstrate how melatonin may contribute to promoting plant growth in salt-stressed environments, which is essential for strategies focused on the sustainable use of saline-alkali land.

The maize seed pedicel, an important tissue connecting the seed to the cob, plays a crucial role in seed development. However, surprisingly little is known about the genetic basis of the maize seed pedicel-placenta (SP) and its impact on seed germination. Here, we established a biomechanical model of maize seed water absorption and dehydration using 50 maize cultivars, and conducted a comparative analysis of SP and its related traits, as well as their effects on seed germination and vigor. The results revealed that SP size is closely related to seed size and that there are differences in SP traits among various cultivars. Removal of the SP can improve seed germination and enhance seed vigor in maize. Additionally, the genetic basis of four SP traits-pedicel-placenta length (PL), pedicel-placenta width (PW), pedicel-placenta thickness (PT), and pedicel-placenta cross-sectional area (PC)- was investigated in a population of recombinant inbred lines (RILs) derived from Xinzi517 & times; B73 and an association panel comprising 368 inbred lines. A total of nine quantitative trait loci (QTLs) controlling these traits were detected: one for PL, three for PW, three for PT, and two for PC. Furthermore, 58 single nucleotide polymorphisms (SNPs) significantly associated with these four traits were identified in the association panel across four environments: 16 for PL, 18 for PW, 19 for PT, and 5 for PC. A total of 61 candidate genes were identified via association analysis and linkage mapping: 18 for PL, 18 for PW, 13 for PT, and 12 for PC. These findings provide insights into the mechanism of seed germination and support the improvement of molecular marker-assisted selection (MAS) for high-vigor maize breeding.

ABSTRACT Accurate evaluation of maize performance across diverse environments is essential for improving yield stability and cultivar adaptation under a changing climate. However, conventional breeding approaches often struggle to address multi‐trait trade‐offs and complex genotype‐by‐environment (G × E) interactions while explicitly incorporating meteorological information. In this study, we developed an integrated framework that combines mixed‐model genetic evaluation, information‐theoretic multi‐trait indices, and machine‐learning‐based environmental prediction. Best linear unbiased prediction (BLUP) was used to estimate genotypic values and variance components from 146,286 raw observations representing 34 maize genotypes evaluated across 53 environments during 2020–2024. Yield and disease resistance were summarized using a mutual‐information‐weighted yield performance index (YPI_MI) and an entropy‐weighted disease resistance index (DRI), respectively. A random forest model was then used to predict YPI_MI from meteorological and soil variables, yielding a cross‐validated R2 of 0.687 and an in‐sample R2 of 0.841. Variable‐importance analysis identified evapotranspiration, precipitation, BLUP‐derived genetic merit, shortwave radiation, and soil pH as the major drivers of performance variation. The proposed framework effectively distinguished genotypes that combined favorable yield potential with disease resistance and provided an interpretable basis for environment‐specific evaluation. Overall, this study offers a practical approach for integrating genetic merit, multi‐trait performance, and environmental information to support maize cultivar assessment and deployment under variable agroclimatic conditions.

Herbivore-induced plant volatiles (HIPVs) play crucial roles in regulating plant defense responses. However, the functions of some HIPVs, particularly in maize seedlings responding to Spodoptera frugiperda larvae, are not well understood. In this study, the HIPVs from maize leaves infested by S. frugiperda were analyzed, larval choice assays for S. frugiperda were performed, and the effects of 4-ethylbenzaldehyde spraying on the maize leaves were assessed. Studies found that levels of 4-ethylbenzaldehyde significantly increased in maize leaves infested by fourth-instar S. frugiperda, which preferred healthy plants. Behavioral assays indicated that this compound effectively repelled the larvae. Spraying it significantly reduced leaf consumption and larval growth, while enhancing SOD, POD, and CAT activities, as well as levels of JA, SA, ABA, total flavonoids, and DIMBOA. Additionally, related defense response gene expression increased, and H2O2 and MDA levels rose at 12 h before returning to control levels at 24 h. These findings indicate that 4-ethylbenzaldehyde enhances maize resistance to S. frugiperda by repelling larvae and inducing plant defenses, including antioxidant enzymes, phytohormones, and secondary metabolites. This suggests that 4-ethylbenzaldehyde may be a valuable signal for enhancing defense responses in pest management.

Context: The use of high-yielding, stable, and widely adaptable summer maize hybrids is essential for the sustainable cultivation of maize globally. However, contemporary breeding programs face challenges in identifying genotypes that exhibit consistent performance while maintaining desired agronomic characteristics across diverse environments. Dynamic shifts in global meteorological and edaphic conditions have impacted the evaluation of summer maize performance in China's multi-environment trials (METs). Multi-perspective analysis of genotype-by-environment interactions (GEI) is then essential for characterizing maize yield stability and trait expression across agroecological zones. Objective: This study aims to comprehensively evaluate the performance and stability of maize genotypes in the Huang-Huai-Hai region by integrating environmental techniques (ETs) with multi-trait selection methods. Methods: Twenty-eight maize hybrids and a check hybrid (ZD958) were evaluated across 29 locations in the Huang-Huai-Hai region of China during the 2019-2021 cropping seasons, using a randomized complete block design (RCBD) with three replications. Results: Based on 30 years (1993-2023) of environmental data, which included 19 meteorological and 6 soil physicochemical factors, the ETs classified the 29 locations across eight provinces into six distinct mega-environments (MEs). The additive main effects and multiplicative interaction (AMMI) model analysis revealed that genotype (G), environment (E), and their interaction (GxE) significantly influenced (p < 0.05) for all agronomic parameters from 2019 to 2021. The combined performance of grain yield and other agronomic traits-such as growth period, plant height, ear height, lodging rate, barren stalk rate, grain moisture content at harvest, ear row number, bare tip length, and 100-grain weight-across different MEs was assessed using the genotype by yield x trait (GYT) biplot approach. The integration of GYT biplots with ETs effectively identified dominant hybrids across different MEs. Among the evaluated hybrids from 2019 to 2021, HY1604 exhibited both high yield and stability in MEs 1-4, categorizing it as a high-yielding, stable hybrid. HY573 and SD610 demonstrated relatively balanced performance in yield-trait combinations in MEs 5 and 6, respectively. The control hybrid, ZD958, showed strong stability but average yield performance over the three-year MET period. Implications: The use of environmental characterization techniques to delineate MEs, combined with the GYT biplot approach to evaluate yield, adaptability, and stability, facilitated precise variety placement, and provided a robust theoretical framework for the comprehensive evaluation of multiple traits in summer maize hybrids in the Huang-Huai-Hai region of China.

The development of superior summer maize hybrids with high-yield potential and essential agronomic traits, such as resistance to lodging, is crucial for ensuring the sustainability of maize cultivation. However, the task of identifying and breeding genotypes that exhibit exceptional performance and stability across multiple environment conditions, while considering a wide range of traits, is challenging. Given the backdrop of global climate change, understanding which climate variables and soil properties most significantly impact environmental similarity is essential for selecting hybrids with improved adaptability to regions with diverse climatic and soil conditions. This study aimed to integrate envirotyping techniques (ETs) with a multi-trait selection approach to carry out a comprehensive evaluation of maize genotypes for performance and stability. The grain yields of 13 maize hybrids, along with their four critical agronomic parameters, were assessed in the Huang-Huai-Hai Plain of China across 40 locations in eight provinces. By considering 20 years of climatic factors and soil covariates, these 40 locations were divided into six mega-environments (MEs) based on similar long-term weather patterns and soil characteristics. Additive main effects and multiplicative interaction (AMMI) analyses revealed that genotype (G), environment (E), and the GxE interaction had significant effects on all agronomic parameters (P < 0.001). The mean performance and stability of the genotypes in each mega-environment were assessed, allowing for the identification of superior hybrids using the multi-trait stability index (MTSI). In two of the MEs (ME2 and ME3), only two hybrids, HY321 and HY9112, were selected concurrently. Overall, this study provides valuable insights into the effects of ETs on maize hybrids and enhances our understanding of GxE interactions in multi-environment trials. This understanding is essential for improving maize cultivation practices and breeding program in diverse environments.

IntroductionWinter wheat is a crucial crop extensively cultivated in northern China, where its grain yield is influenced by genetic factors (G), environmental conditions (E), and their interactions (GEI). Accurate yield estimation depends on understanding the patterns of GEI in multi-environment trials (METs).MethodsFrom 2014 to 2018, continuous experiments were conducted in the Heilonggang region of the North China Plain (NCP), evaluating 71 winter wheat genotypes across 16 locations over five years. Leveraging 30 years of environmental data, including 19 meteorological parameters and 6 soil physicochemical properties, the study analyzed GEI and identified four distinct mega-environments (MEs) using advanced environmental classification techniques.ResultsVariance analysis of genotype-year combinations at individual locations revealed significant differences among genotypes. Furthermore, the joint analysis showed that GEI variance exceeded the variance attributed to genotypic effects alone. The Additive Main Effects and Multiplicative Interaction (AMMI) model indicates that the first three interaction principal component axes (IPCAs) account for over 70% of the GEI variance, thereby demonstrating the relevance of this model to the current study. Principal Component Analysis (PCA) across the five-year study period revealed positive correlations between grain yield and vapor pressure deficit (VPD), evapotranspiration potential (ETP), temperature range (TRANGE), available soil water (ASKSW), and sunshine duration. Conversely, negative correlations were observed with relative humidity at 2 meters (RH2M), total precipitation (PRECTOT), potential evapotranspiration (PETP), and dew point temperature at 2 meters (T2MDEW). Among the meteorological and soil variables, minimum temperature (TMIN), fruiting rate (FRUE), temperature at 2 meters (T2M), and clay content (CLAY) emerged as the most significant contributors to yield variation during the study period. Based on GGE biplot analysis, superior genotypes were identified for their respective regions: JM196, WN4176, and HN6119 in 2014; ZX4899, H9966, and LM22 in 2015; BM7, KN8162, and KM3 in 2016; HH14-4019, HM15-1, and HH1603 in 2017; and S14-6111 and JM5172 in 2018. Feixiang and Shenzhou were identified as the most discriminative and representative locations.DiscussionThese findings provide a scientific basis for optimizing winter wheat cultivation strategies in northern regions. Based on long-term data from the North China Plain, future work can further validate their applicability in other regions.

To explore the application of seed germination biomechanical event(s) in seed vigour tests, a new procedure for the evaluation of maize seed vigour tests based on pericarp–testa rupture (PR) and coleorhiza rupture (CR) during seed germination was developed. Twenty–four lots of hybrid maize were used to determine the feasibility of the rupture test (RT) as a seed vigour test in Zea mays. The results showed that the physiological quality pattern of 24 maize seed lots assessed through RT was similar to that obtained through analysis with other seed test methods. Correlation and regression analyses revealed that the percentage of CR and percentage of PR + CR at “15 ± 0.5 °C for 120 h ± 1 h” and “20 ± 0.5 °C for 72 h ± 15 min” exhibited positive correlations with the field seedling emergence data (p < 0.01). Hence, the proposed method (the rupture test) is cogent and effective, thus providing an important reference for more crops to select for seed germination event(s) and establishing corresponding new methods for seed vigour tests in the future.

In response to the growing population and increasing demand for cattle products, enhancing sorghum forage yield is essential for ensuring food security. This study aimed to identify stable genotypes with high forage yields and key yield traits for sorghum breeding programs. Ninety-five forage sorghum lines were evaluated under five distinct climatic conditions over two years (2020–2021), revealing significant genotype × environment interaction (GEI) effects for 14 agronomic traits. Two BLUP-based mixed model stability methods, weight average absolute score based on BLUP (WAASB) and the multi-trait stability index (MTSI), were employed for stability analysis. Three genotypes, G90 (424B), G80 (382B) and G3 (349B) were identified stable and high yielding for forage yield based on WAASB based methods. The MTSI, a novel simultaneous selection index, effectively selected genotypes based on multiple agro-morphological traits, except for the leaf-to-stem ratio. Genotypes G81, G90, G80, and G89 were identified as desirable based on the MTSI. The strength and weakness plot is highlighted as a valuable graphical tool for identifying and selecting genotypes based on trait strengths and weaknesses. Among these, G90 (424B) and G80 (382B) stood out as superior, excelling in both forage yield and early maturity, as determined by WAASB based methods and MTSI method. These genotypes warrant further comprehensive investigation across diverse environments and show significant potential for future breeding programs.

Spodoptera frugiperda (Lepidoptera: Noctuidae), a pest with an amazing appetite, damages many crops and causes great losses, especially maize. Understanding the differences in different maize cultivars’ responses to S. frugiperda infestation is very important for revealing the mechanisms involved in the resistance of maize plants to S. frugiperda . In this study, a comparative analysis of two maize cultivars, the common cultivar ‘ZD958’ and the sweet cultivar ‘JG218’, was used to investigate their physico-biochemical responses to S. frugiperda infestation by a pot experiment. The results showed that the enzymatic and non-enzymatic defense responses of maize seedlings were rapidly induced by S. frugiperda . Frist, the hydrogen peroxide (H 2 O 2 ) and malondialdehyde (MDA) contents of infested maize leaves were significantly increased and then decreased to the level of the control. Furthermore, compared with the control leaves, the puncture force values and the total phenolics, total flavonoids, and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one contents of infested leaves were significantly increased within a certain time. The superoxide dismutase and peroxidase activities of infested leaves were significantly increased in a certain period of time, while the catalase activities decreased significantly and then increased to the control level. The jasmonic acid (JA) levels of infested leaves were significantly improved, whereas the salicylic acid and abscisic acid levels changed less. Signaling genes associated with phytohormones and defensive substances including PAL4 , CHS6 , BX12 , LOX1 , and NCED9 were significantly induced at certain time points, especially LOX1 . Most of these parameters changed greater in JG218 than in ZD958. Moreover, the larvae bioassay showed that S. frugiperda larvae weighed more on JG218 leaves than those on ZD958 leaves. These results suggested that JG218 was more susceptible to S. frugiperda than ZD958. Our findings will make it easier to develop strategies for controlling S. frugiperda for sustainable maize production and breeding of new maize cultivars with increased resistance to herbivores.

种子是农业科技的载体,种子质量代表着国家农业科技水平,决定了品种推广范围、播种方式及种子市场竞争力.质量调研作为种子质量保障的一项基础性工作,对推动现代种业高质量发展发挥着重要作用.从包衣包装、4项基本指标测定、种子活力测定、合格率、交流问卷等方面回顾了中国玉米主产区市售品种样品种子质量十年变迁概况,并从种子质量标准认证建设、种企高质量种子生产能力提升、种子质量科普培训及市场监管等方面对玉米种子质量有效控制、保障用种安全提出了一些建设性意见,为推进新时代中国现代玉米产业高质量发展提供参考.

Under global climate changes, understanding climate variables that are most associated with environmental kinships can contribute to improving the success of hybrid selection, mainly in environments with high climate variations. The main goal of this study is to integrate envirotyping techniques and multi-trait selection for mean performance and the stability of maize genotypes growing in the Huanghuaihai plain in China. A panel of 26 maize hybrids growing in 10 locations in two crop seasons was evaluated for 9 traits. Considering 20 years of climate information and 19 environmental covariables, we identified four mega-environments (ME) in the Huanghuaihai plain which grouped locations that share similar long-term weather patterns. All the studied traits were significantly affected by the genotype × mega-environment × year interaction, suggesting that evaluating maize stability using single-year, multi-environment trials may provide misleading recommendations. Counterintuitively, the highest yields were not observed in the locations with higher accumulated rainfall, leading to the hypothesis that lower vapor pressure deficit, minimum temperatures, and high relative humidity are climate variables that –under no water restriction– reduce plant transpiration and consequently the yield. Utilizing the multi-trait mean performance and stability index (MTMPS) prominent hybrids with satisfactory mean performance and stability across cultivation years were identified. G23 and G25 were selected within three out of the four mega-environments, being considered the most stable and widely adapted hybrids from the panel. The G5 showed satisfactory yield and stability across contrasting years in the drier, warmer, and with higher vapor pressure deficit mega-environment, which included locations in the Hubei province. Overall, this study opens the door to a more systematic and dynamic characterization of the environment to better understand the genotype-by-environment interaction in multi-environment trials.

Facing the trend of increasing population, how to increase maize grain yield is a very important issue to ensure food security. In this study, 28 nationally approved maize hybrids were evaluated across 24 different climatic conditions for two consecutive years (2018-2019). The purpose of this study was to select high-yield with stable genotypes and identify important agronomic traits for maize breeding program improvement. The results of this study showed that the genotype x environment interaction effects of the 12 evaluated agronomic traits was highly significant (P < 0.001). We introduced a novel multi-trait genotype-ideotype distance index (MGIDI) to select genotypes based on multiple agronomic traits. The selection process exhibited by this method is unique and easy to understand, so the MGIDI index will have more and more important applications in future (please indicate what does it mean MET before abbreviating it) METs research. The genotypes selected by the MGIDI index were G22, G10, G12 and G1 as the high yielding and stable genotypes. The parents of these selected genotypes have the ability to play a greater role as the basic germplasm in the breeding process. A new form of (please indicate what does it mean GGE before abbreviating it) GGE technician, geno-type*yield*trait (GYT) biplot, based on multiple traits for genotypes selection was also applied in this study. The GYT biplot ranked genotypes by combining grain yield with other evaluated agronomic traits, and displayed the distribution of their traits, namely strengths and weaknesses.

为准确评价黄海海地区夏玉米品种的稳定性、适应性和丰产性,采用稳定性指数(WAASB)和同时选择指数(WAASBY)对2018-2019年黄淮海地区25个夏玉米品种进行连续2年的产量进行分析.结果表明:籽粒产量在不同品种和试点间存在极显著差异(P＜0.001),品种和试点间存在极显著互作效应.GY(籽粒产量)×WAASB双标图显示,'衡玉7182','衡9','华农138','宝玉168','郑单958'和'蠡玉86'等品种为丰产性突出、稳定性较好的品种.其中,'衡9'的WAASBY得分最高,属于参试品种中表现较好的品种之一.而'农大108'的WAASBY得分最低,属于表现较差的品种之一.安阳、德州、石家庄和邯郸最适宜种植的夏玉米品种均为'浚单29'、'农大108'、'浚单20'和'裕丰 303',深州最适宜种植的品种是'登海685',运城最适宜种植的品种是'中单856'、'衡玉7182'和'梦玉908'.综上所述,WAASB和WAASBY可为黄淮海夏玉米品种的示范和推广提供依据.

Increasing the maize production capacity to ensure food security is still the primary goal of global maize planting. The purpose of this study was to evaluate genotypes with high yield and stability in summer maize hybrids grown in the Huanghuaihai region of China using additive main effects and multiplicative interaction (AMMI) analysis and best linear unbiased prediction (BLUP) technique. A total of 18 summer maize hybrids with one check hybrid were used for this study using a randomized complete block design (RCBD) with three replicates at 74 locations during two consecutive years (2018–2019). A three-way analysis of variance (ANOVA) and an AMMI analysis showed that genotype (G), environment (E), year (Y) and their interactions were highly significant (p < 0.001) except G × E × Y for all evaluated traits viz., grain yield (GY), ear length (EL), hundred seed weight (HSW) and E × Y for hundred seed weight. The first seven interaction principal components (IPCs) were highly significant and explained 81.74% of the genotype by environment interaction (GEI). By comparing different models, the best linear unbiased prediction (BLUP) was considered the best model for data analysis in this study. The combination of AMMI model and BLUP technology to use the WAASB (weighted average of absolute scores from the singular value decomposition of the matrix of BLUP for GEI effects generated by linear mixed model) index was considered promising for similar research in the future. Genotypes H321 and Y23 had high yield and good stability, and could be used as new potential genetic resources for improving and stabilizing grain yield in maize breeding practices in the Huanghuaihai region of China. Genotypes H9, H168, Q218, Y303 and L5 had narrow adaptability and only apply to specific areas. The check genotype Z958 had good adaptability in most environments due to its good stability, but it also needs the potential to increase grain yield. Significant positive correlations were also found between the tested agronomic traits.

Crop performance is seriously affected by high salt concentrations in soils. To develop improved seed pre-sowing treatment technologies, it is crucial to improve the salt tolerance of seed germination. Here, we isolated and identified the strain Bacillus sp. MGW9 and developed the seed biostimulant MGW9. The effects of seed biopriming with the seed biostimulant MGW9 in maize ( Zea mays L.) under saline conditions were studied. The results show that the strain Bacillus sp. MGW9 has characteristics such as salt tolerance, nitrogen fixation, phosphorus dissolution, and indole-3-acetic acid production. Seed biopriming with the seed biostimulant MGW9 enhanced the performance of maize during seed germination under salinity stress, improving the germination energy, germination percentage, shoot/seedling length, primary root length, shoot/seedling fresh weight, shoot/seedling dry weight, root fresh weight and root dry weight. Seed biostimulant MGW9 biopriming also alleviated the salinity damage to maize by improving the relative water content, chlorophyll content, proline content, soluble sugar content, root activity, and activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase, while decreasing the malondialdehyde content. In particular, the field seedling emergence of maize seeds in saline-alkali soil can be improved by biopriming with the seed biostimulant MGW9. Therefore, maize seed biopriming with the seed biostimulant MGW9 could be an effective approach to overcoming the inhibitory effects of salinity stress and promoting seed germination and seedling growth.

以郑单958、先玉335、蠡玉16和迪卡007等4个玉米品种种子为材料,通过对果种皮特性、发芽能力、幼苗生长、种子化学成分、酶活性等进行测定,研究果种皮对种子萌发及生理特性的影响.结果表明,果种皮最大吸水量、覆胚果种皮(TCE)穿刺力和TCE厚度等3项指标在4个品种间均存在差异,其中郑单958的3项指标均最大,分别为1.02 g·(50粒)-1、1.81 N和53.33μm;移除TCE后,4个品种种子的发芽指数、芽(苗)长、主根长、芽(苗)鲜重、芽(苗)干重、根鲜重和根干重等7项指标与对照相比均明显上升.此外,25℃条件下萌发60 h,4个品种种子胚根鞘破裂率均明显提高,且胚中部、胚根和胚根鞘组织内过氧化氢酶、过氧化物酶、超氧化物歧化酶的活性基本呈上升趋势;不同种子质量指标相关性分析表明,TCE穿刺力和TCE厚度之间呈极显著正相关,该2项指标与发芽势、平均发芽天数、种子总淀粉含量3项指标均呈正相关,但与芽(苗)长、主根长、芽(苗)鲜重、芽(苗)干重、根鲜重、根干重和种子粗脂肪含量等7项指标均呈负相关.研究表明,玉米果种皮特别是TCE相关生物力特性会影响种子萌发及生理特性,这可为进一步研究玉米种子萌发调控及高活力形成机理提供理论基础.

The correct interpretation of the adaptability and stability of maize ( Zea mays L.) hybrids in different ecological environments is very important for plant breeders. Additive main effect and multiplicative interaction model and genotype main effects and genotype × environment interaction biplot are the two most popular methods in the analysis of genotype × environment interaction in multienvironment trials. We conducted an experiment designed to examine and evaluate the adaptability and stability of four agronomic traits of 19 tested maize genotypes in two consecutive growth cycles across seven provinces including 37 locations using a randomized completely block design with three replicates. The combined ANOVA for all traits showed that the effect of genotype, environment, and genotype × environment interaction were significant at 0.1% probability levels. In order to evaluate multiple agronomic traits more accurately, multitrait stability index (MTSI) as an emerging selection method based on mean performance and stability was adopted. Agronomic trait grain yield (GY) was positively correlated with grain weight per ear and growth period. In addition, it was also found that GY and bar tip length showed obvious negative correlation. The MTSI is very helpful for breeders who hope to select mean performance and stability based on a variety of agronomic traits because it provides a convenient selection process while taking into account the relevant results of the traits.

Stability and adaptability of promising maize hybrids in terms of three agronomic traits (grain yield, ear weight and 100-kernel weight) in multi-environments trials were evaluated. The analysis of AMMI model indicated that the all three agronomic traits showed highly significant differences (p < 0.01) on genotype, environment and genotype by environment interaction. Results showed that genotypes Hengyu321 (G9), Yufeng303 (G10) and Huanong138 (G3) were of higher stability on grain yield, ear weight and 100-kernel weight, respectively. Genotypes Hengyu1587 (G8) and Hengyu321 (G9) showed good performance in terms of grain yield, whereas Longping208 (G2) and Weike966 (G12) showed broad adaptability for ear weight. It was also found that the genotypes with better adaptability in terms of 100-kernel weight were Zhengdan958 (G5) and Weike966 (G12). The genotype and environment interaction model based on AMMI analysis indicated that Hengyu1587 and Hengyu321 were the ideal genotypes, due to extensive adaptability and high grain yield under both testing sites. Bangladesh J. Bot. 50(2): 343-350, 2021 (June)

以国内广泛种植的先玉335双亲为测验种,采用NC Ⅱ遗传交配设计,对25份国外玉米自交系进行两年配合力测定试验,通过对供试国外玉米自交系的一般配合力、组配杂交组合的特殊配合力及较对照的优势等进行分析,筛选出一般配合力优良的国外玉米自交系,提出其合理利用的方案.结果表明,供试国外自交系中PHWG5、787、78371A、6M502、LH128等产量GCA效应值表现优良,LH194、L139、OS602等宜机收性状GCA效应值表现优良.综合产量、倒伏率和收获时含水量的GCA表现,PHN29、PHM10、PHR32等3份自交系表现较好.杂交组合PHWG5×PH6WC的产量在所有组合中最高,且较4个对照品种增产幅度都较高,可进一步试验.