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.

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.

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.

Abiotic stresses, including cold and drought, negatively affect maize ( Zea mays L.) seed field emergence and later yield and quality. In order to reveal the molecular mechanism of maize seed resistance to abiotic stress at seed germination, the global transcriptome of high- vigour variety Zhongdi175 exposed to cold- and drought- stress was analyzed by RNA-seq. In the comparison between the control and different stressed sample, 12,299 differentially expressed genes (DEGs) were detected, of which 9605 and 7837 DEGs were identified under cold- and drought- stress, respectively. Functional annotation analysis suggested that stress response mediated by the pathways involving ribosome, phenylpropanoid biosynthesis and biosynthesis of secondary metabolites, among others. Of the obtained DEGs (12,299), 5,143 genes are common to cold- and drought- stress, at least 2248 TFs in 56 TF families were identified that are involved in cold and/or drought treatments during seed germination, including bHLH, NAC, MYB and WRKY families, which suggested that common mechanisms may be originated during maize seed germination in response to different abiotic stresses. This study will provide a better understanding of the molecular mechanism of response to abiotic stress during maize seed germination, and could be useful for cultivar improvement and breeding of high vigour maize cultivars.

利用AMMI模型和GGE双标图,对2015年河北省夏播玉米区域试验中13个参试品种在10个试点的相关农艺性状进行分析,包括子粒产量、穗长和千粒重.结果 表明,各农艺性状在不同基因型和环境间存在极显著差异,基因型和环境间存在极显著互作效应.参试品种丰产性表现较好的有龙华369、J1302、衡玉1182,丰产性表现较差的有澳玉698、JF33.衡玉1182、J1302、荃玉18、郑单958和龙华369品种稳定性表现较好,鑫研218稳定性最差.丰产性、稳产性和适应性较好的品种有J1302、衡玉1182和龙华369.

To evaluate the adaptability and stability of silage maize cultivars and identify the representativeness and discrimination of each testing site, a two-year field research in a randomized complete block design (RCBD) with three replicates at 10 testing sites was conducted. An additive main effect and multiplicative interaction (AMMI) model and a genotype plus genotype environment interactions (GEI) biplot (referred to as GGE hereafter) were used to analyze the data. The two-year test revealed that four cultivars (Zhongdi 175 (ZD175), Qiushuo 008 (Q008), Hengyu 1587 (H1587), and Yayuqingzhu 8 (Y8) exhibited high yield and good stability, whereas two cultivars (Zhongbeiqingzhu 410 (Z410) and Fangyu 36 (F36) had low yield and poor stability. The comprehensive application of the AMMI model and the GGE biplot could accurately and intuitively evaluate the high yield, stability, and adaptability of each cultivar.

Maize is one of the most important cereal crops supporting millions of people in China. The main purpose of this research was to assess the genotype by environment interaction (GEI) and yield performance of 20 maize genotypes in 16 different environments of Huang-Huai-Hai area, China. In this research, the additive main effects and multiplicative interactions (AMMI) model was applied to analyze the GEI effect and to evaluate the suitability and yield stability of 20 different maize genotypes. The AMMI model analysis indicated that genotype (G), environment (E) and GEI had significant effects on grain yield and the contribution to the total sum of squares difference was 3.10%, 35.05% and 42.25%, respectively, suggesting that GEI was the primary factor affecting grain yield. The AMMI model analysis partitioned sum of squares of GEI into fourteen interaction principal components axes (IPCA), of which all the IPCA were significant (P < 0.01) and the first five IPCA (IPCA1, IPCA2, IPCA3, IPCA4 and IPCA5) explained 77.7% of variation. The AMMI model analysis using IPCA1 scores and G main effect indicated that two genotypes Hengyul47 and Hengyu321 had relatively stable performance across the environments. Among the locations, Quwo was the most productive site in distinguishing genotypes and the most representative environment. In conclusion, this study suggested that genotype and environment interactions were the major source of variation in maize yield, and use of AMMI model seemed useful for screening and identifying the response of summer maize genotypes in different environments. (C) 2019 Friends Science Publishers

The genotype (G) by environment (E) interaction (GEI) determines the stability of maize grain yield in multi-environment trials (METs). This study evaluated the high-yielding and promising maize genotypes over years and locations by the additive main effects and multiplicative interaction (AMMI) model. The grain yield of 13 spring maize genotypes was evaluated for two consecutive years (2012-2013) when planted in six and eight ecological environments, respectively, using a randomized complete block design (RCBD) with three replications. The AMMI model explained 77.49 and 75.57% of total observed genotypic variation, respectively. A comprehensive analysis of variances showed a highly significant impact of environment, genotype and genotype x environment (GE) interaction on grain yield (P < 0.01). The AMMI model analysis of variance showed that the environment contributed the most to variations in grain yield (55.58 and 72.50% of the total variation, respectively), followed by GE interaction (24.61 and 10.71% of the total variation, respectively) and genotype (3.01 and 3.01% of the total variation, respectively). Among the interaction effects, first interaction principal component axis (IPCA1), IPCA2 and IPCA3 explained the vast majority of genetic and environmental interaction information. Two years of experimental data showed that the genotype with high yield and stability was G4 (Zhongdi175) while G3 (C807) and G8 (LY10) of poor yield and unstable. The check genotype G6 (Nongda108) had good stability and general high-yielding. The best and worst discriminative environments for each of the locations in 2012-2013 were XT (Xingtai) and LH (Longhua), WA (Wuan) and PQ (Pingquan), respectively. (C) 2019 Friends Science Publishers

探讨玉米广适性品种在不同水分条件下的农艺和生理特征,为广适性新品种培育提供参考依据.2015年和2016年,将玉米品种‘先玉335'郑单958’与玉米新品种‘衡玉321’,在干旱和正常灌溉2个水分处理下种植于河北省农科院节水试验站,试验采用裂区设计.测定株高、穗位、抽雄期、吐丝期、籽粒产量和产量要素等农艺学性状,以及抽雄前叶绿素含量(SPADv)、灌浆期叶绿素含量(SPADg)、灌浆后期叶片衰老等级评分(LSS)、抽雄前叶面积指数(LAIv)、灌浆期叶面积指数(LAIg)等生理性状,比较不同品种间的性状差异.玉米品种穗粗、秃尖长品种间差异不显著,其他性状品种间存在差异.与干旱处理相比,正常灌溉处理下,‘衡玉321’、‘郑单958’和‘先玉335’的籽粒产量分别增加5 056.5 kg/hm2、3 987.5 kg/hm2和5 934 kg/hm2,穗行数增加3.5、2.3、2.3,百粒重增加4.7 g、5.2 g、6.8 g,株高增加46.7 cm、44.1 cm、66.7 cm.‘衡玉321’在正常灌溉处理和干旱处理下的LRS、SPADg分别是5.97、3.85和5.81、3.27.广适性品种‘衡玉321’株型紧凑,抽穗后叶片衰老速度慢;干旱条件下叶片发生明显卷曲,但叶绿素含量较高,叶功能好;产量、千粒重和株高的水分敏感性低,而穗数和穗粒数的水分敏感性较高,灌浆中期的叶绿素含量和抽穗前叶面积指数对水分不敏感,水旱条件下均表现出高产.

A multi-environment trial of maize cultivars in the north of China was conducted at 17 sites to assess the agronomic traits and test location representativeness. An additive main effects and multiplicative interaction (AMMI) model and a genotype main effect (G) and genotype and environment interaction (GE), (GGE) biplot were used to analyze the data. Results showed that the grain yields of summer maize cultivars were remarkably influenced by environment (E), genotype (G), and genotype by environment interaction (GEI). The effect of GEI was 1.53 times higher than that of genotypes. The cultivars Hengyu1182, Longhua369 and J1302 exhibited good yield and stability. Among sites Baoding, Xinle, Yutian and Zhengding showed good discriminating ability while Langfang, Gaoyang and Tanchang sites displayed good representativeness. In correlation analysis, agronomic traits, such as ear length, kernel row number, and 1000-grain weight were positively correlated with maize yield. Conversely, barren ear tip was negatively correlated with yield. This study confirmed that the AMMI model and GGE biplot are effective methods for exploring the stability and adaptability of genotypes and representative patterns of biplots in crop breeding and subsequent cultivar recommendations. (C) 2019 Friends Science Publishers

This study evaluated the yield performance of 27 maize (Zea mays L.) genotypes from 2016 to 2017 in 80 trial environments in Huang-huai-hai summer maize growing area of China during summer by using a randomized complete block design (RCBD) with three replications. Grain-yield data obtained from the regional trials of the Kechuang Union were analyzed with a genotype-and-genotype-by-environment (GGE) biplot. Analysis of variance (ANOVA) of grain-yield data showed that the effects of environment, genotype, and genotype-by-environment interaction were significant, accounting for 45.27%, 9.18%, and 27.39% of the sum of treatment combinations in 2016, as well as 53.97%, 9.43%, and 19.81% of that in 2017, respectively. Results showed that the best performance and candidate genotypes for the 2016-2017 multi-environment trials were D56, J118, and H321, as well as S617, D205 and D56, respectively. Among the 80 test sites, the environments TA and XJ in 2016 and the environment JX in 2017 were included in the ideal environment due to their excellent discrimination and representativeness.

为客观准确评价多点鉴定试验中玉米新品种丰产性、稳产性和适应性以及试点辨别力和代表性,探明适合黄淮海夏玉米多点鉴定试验基因型与环境互作分析方法.本研究借助AMMI模型和GGE双标图分析方法对2017年黄淮海夏玉米新品种多点鉴定试验中10个不同基因型品种在15个不同生态环境下的品种丰产性和稳定性进行分析,并对试点环境辨别力和代表性进行综合评价.结果 表明:基因型效应、环境效应和基因型与环境互作均达到了极显著差异,基因型与环境互作是产量变异的主要来源.‘衡玉1587’和‘衡玉321’综合表现较好,属于丰产性、稳定性和适应性均较好的品种.‘伟科702’稳定性较好但丰产性较差,‘浚单20’丰产性较好且具有较强的适应性,可以在适宜地区推广种植.河北深州和山东德州具有较强辨别力和代表性,‘衡玉1587’和山东德州分别是理想品种和理想试点.AMMI模型和GGE双标图分析结果基本一致,两种方法优势互补,可以用来作为分析基因型与环境互作的理想工具.

A field experiment was conducted at Shenzhou of Hebei province to study on grain-filling characteristics of maize hybrids differing in maturities, aimed to provide scientific information for the regulation of grain weight and selection of maturity. Four maize hybrids differing in maturities were used as experimental materials, under the same planting density. The main results were as follows. All the hybrids reached the maximum value of 100 grain fresh weight at 40d after pollination, and then declined slowly. The maximum value of 100 grain fresh weight of middle-maturity hybrid Zhengdan958 was the highest, and early maturity hybrid Demeiyal was the lowest. After 40 days of pollination, all the hybrids reached the maximum value of 100 seed fresh weight, and then declined slowly, and the maximum 100 fresh weight of middle-late hybrid Zhengdan958 was the highest, and early-maturity hybrid Demeiyal was the lowest. Four hybrids of 100 grain dry weight and fresh weight showed the same trend, it was a rapid growth period at 40d after pollination, the 100 grain dry weight of Hengyul182 was maximum, Demeiyal was minimum. The grain-filling rate of four hybrids showed a single peak curve, reached the maximum peak at 20d after pollination, the peak performance of four maize hybrids showed that Hengyul182> Zhengdan958> Nongda108 > Demeiyal. The percentage of grain water of Hengyul182 was the lowest, the value was 25.70% when 60d after pollination, Nongda108 was significantly higher than the other three hybrids (P<0.05), the value was 34.01%. The grain-filling processes of maize hybrids differing in maturities were analyzed by Logistic model, and the total filling period could be divided into early stage, middle stage and late stage. Middle-early hybrid Hengyul182 showed that grain weight of every stage (W-1-W-3), and mean grain-filling rate of every stage (P-1-P-3) were higher than other three types. The results showed that the increase of grain weight was related to grain filling rate at filling stage, and the middle-early maturity hybrids suitable for planting in Heilonggang area. (C) 2018 Friends Science Publishers

衡玉1182是河北省农林科学院旱作农业研究所以H82为母本、H11为父本杂交组配而成的玉米新品种,具有早熟、耐密、高产、优质、多抗且适应性广等特点,适宜在河北省唐山和廊坊市及其以南的夏播玉米区夏播种植.该品种制种技术简便、产量高,开发应用前景乐观.

During maize multi-location test of Hebei Province, China in 2013-2014, 10 spring maize cultivars (control included) were evaluated at 8 experiment sites, then the grain yield and main ear characteristics (ear length, row per ear, and 1 000-kernel weight), were analyzed by GGE (genotype main effect plus genotype-environment interaction)-biplot. Results showed that adaptability of cultivar Zhongdi175 was the best among all the 10 evaluated maize in all the evaluated traits. That is, cultivar Zhongdi175 is the best cultivars in the experiment. In addition, Zhulu was the most ideal experiment site due to its best discrimination for maize cultivars. This study showed that GGE-plot analysis was an objective and effective method for evaluating maize adaptability, yield, and stability.

Three maize varieties were planted as the main corn varieties in the Huang-huai-hai Plain as materials with five planting densities. Differences in grain filling and mechanised harvest grain characteristics to planting density amongst summer maize cultivars were examined. As plant density increased, the 100-grain dry weights of the three varieties gradually decreased. In the filling period, the 100-grain fresh weights increased initially and then decreased, and the 100-grain fresh weights decreased as plant density increased. At different densities, the grain-filling rates of the three varieties showed single-peak curves, and the highest peak of the grain-filling rate was achieved 30 days after pollination. In the whole grain-filling period, the different densities of the three maize varieties exhibited a decline in the percentage of grain water (PGW). The grain-filling processes of maize varieties with different plant densities were analysed with a logistic model, and the total filling period was divided into gradual increase stage, rapid increase stage and slow growth stage. The yield factors of the three varieties were also analysed. With the increased density, the number of lines per ear (NE), the number of grains per line (NL) and 1000-grain weight (GW) decreased. The grain yield initially increased and then decreased. The maximum yields of Zhengdan958 and Liyul6 were achieved at a density of 75,000 plants ha(-1), and the yield of Hengdan6272 was obtained at 90,000 plants ha(-1). These results indicated that the negative effects of dense planting on grain filling and mechanised harvest grain functions in Hengdan6272 were lower than those in Zhengdan958 and Liyul6 and suggested that the yielding potential of the former variety was higher than that of the latter two. (C) 2018 Friends Science Publishers.

利用NCII遗传交配设计,以国内目前大面积推广的杂交种先玉335双亲为测验种,对80个美国解禁自交系进行2年配合力试验.结果表明,解禁美国自交系遗传基础丰富,不同杂交组合F1代产量平均相对离差21.96％,收获时与对照均值比较,子粒含水量较少,穗轴较细,穗位高较低.筛选出一般配合力高、综合性状较好的美自交系NS701、PHW03、PHN29、PHP55等.黄淮海试验推荐的对照品种先玉335、郑单958、迪卡517、农华101、宇玉30这5个杂交种以及先玉335和郑单958双亲组配的4个杂交组合中,迪卡517、宇玉30等新品种表现出早熟、抗逆、易机收等特点,郑58×PH6WC、郑58×PH4CV产量性状和抗倒伏较好.