泰国玉米生产和遗传改良研究

玉米是泰国一种重要的谷类作物。2000年种植面积估计为1.30百万公顷,籽粒产量约4.48百万吨。杂交种种植面积占到玉米总面积的85?08％,以单交种类型为主,占到杂交种各种类型的74％,其次为三交种。玉米生产主要限制因素为病害(高粱霜霉、南方锈、茎腐、大斑、小斑病)、虫害(亚洲玉米螟)和干旱胁迫。玉米种质发展和品种遗传改良开始于1950年,主要从事单位为农业部农业厅和大学部肯色萨大学。先后育成Suwan 1、Suwan 2、Suwan 3,Nakhon Sawan 1,Suwan 5等改良群体和Suwan Complex、KS 23 broadbase syn.。并从中提取出Ki21、45、Ni1等几十个优良系,组配出Suwan 2301、3851、Nakhon Sawan 72等十多个优良杂交种。分别应用10个群体双列杂交法、顶交法和优良适应品种与外引种质杂交法等,确定了如下几个杂种优势模式：(Suwan 1,Suwan 3)×(Caripeno DMR,KS6);(Suwan 1,Suwan 3,KS6选育系)×(Ki21,Mo17衍生系);[KS 23(S)C2,Suwan 5(S)C3]×[Suwan 1(S)C11]。 Abstract：Maize is one of major cereal crops in Thailand.In the year 2000,it was estimated that the planted area is of 1.30 million hectares and produces about 4.48 million tons.The amount of hybrid seed was 17.76 thousand tons with acquiring 85.08％ of total planted area.Production constraints main were biotic and abiotic factors,involving diseases of sorghum Downy Mildew,Southern rust,Southern corn leaf blight,Northern corn leaf blight and Charcoal stalk rot and inset of the Asian corn borer,and drought stress.The maize research for germplasm development and varietal genetic improvement in Thailand was initiated by the Department of Agriculture in 1950 and Kasetsart University in 1958.Several elite populations of Suwan 1,Suwan 2,Suwan 3, Suwan 5,KS6,KS23,and Suwan-Complex were developed.The superior lines of Ki21,Ki 45,Ni1 etc and elite hybrids of Suwan 2301,Suwan 3851,Nakhon Sawan72＃ etc. were bred.In order to search for heterotic partners,diallel crosses of elite populations with differing in genetic background were performed by the breeding program.The several heterotic partners were determined.i.e.(Suwan 1,Suwan3)×(Caripeno DMR,KS6);(Inbred lines from Suwan 1,Suwan 3,KS6)×(Ki21,a Mol7 derivative line) and [KS 23(S)C2,Suwan 5(S)C3]×[Suwan 1(S)C11].     

俄罗斯远东及黑龙江省春小麦种质资源的遗传多样性北大核心CSCD

利用31个SSR引物分析56份俄罗斯远东地区春小麦(Triticum aestivum)及56份黑龙江省2010生(区)试品系的遗传变异和群体结构。结果表明,黑龙江省春小麦和俄罗斯远东春小麦明显分化为两大类群,聚类结果同地理来源的划分基本一致;居群间和个体间都存在显著性差异;群体的遗传分化程度较高,但群体间的基因交流有限,血缘相对比较单一。鉴于部分黑龙江省同一育种单位的品种(系)间的遗传距离非常相近,目前亟需拓宽和创制新的小麦种质资源。实验结果证明种质资源遗传多样性与地理来源和人为选择压力密切相关。     

俄罗斯远东及黑龙江省春小麦种质资源的遗传多样性

利用31个SSR引物分析56份俄罗斯远东地区春小麦(Triticum aestivum)及56份黑龙江省2010生(区)试品系的遗传变异和群体结构。结果表明,黑龙江省春小麦和俄罗斯远东春小麦明显分化为两大类群,聚类结果同地理来源的划分基本一致;居群间和个体间都存在显著性差异;群体的遗传分化程度较高,但群体间的基因交流有限,血缘相对比较单一。鉴于部分黑龙江省同一育种单位的品种(系)间的遗传距离非常相近,目前亟需拓宽和创制新的小麦种质资源。实验结果证明种质资源遗传多样性与地理来源和人为选择压力密切相关。     

设施黄瓜育成品种果实外观品质的遗传多样性分析

对我国新育成的不同生态类型的138个设施黄瓜品种的19个果实外观性状进行了调查分析,研究其遗传多样性。结果表明,参试品种质量性状的遗传多样性指数都小于数量性状,不同生态类型黄瓜品种果实外观性状的遗传多样性指数为华北型(1.33)>华南型(1.25)>欧洲温室型(1.0)。质量性状的遗传多样性指数为华南型(0.91)>华北型(0.65)>欧洲温室型(0.48);数量性状的遗传多样性指数为华北型(1.94)>华南型(1.56)>欧洲温室型(1.47)。华南型品种果实数量性状的变异系数均高于华北型和欧洲温室型品种。主坐标轴分析(PCO)将所有种质划分为3个区组,即1区为华北型种质优势区、2区为华北型华南型和欧洲温室型种质混合分布区、3区为华南型种质区。PCO结果表明,1区和2区发生了基因渗透。对交流区域中华北型品种自交分离,后代中出现的稀刺瘤和光皮种质的情况进一步验证了基因渗透的结果。参照育成品种的果实性状信息对黄瓜以后的育种工作提出了建议。     

东北春大豆种质资源表型分析及综合评价

种质资源是大豆遗传育种和解析复杂数量性状的基础,通过对种质资源的评价,可指导育种实践中优异互补亲本的选择,提高优异基因交流累加和新品种培育的效率。本研究选用来自东北三省一区1923-2010年间选育的340份春大豆种质资源,通过在牡丹江地区对12个表型性状的2年综合鉴定,评价品种群体遗传变异特点和筛选优异种质资源,结果表明:(1)春大豆种质资源表型变异丰富。除生育期年份间差异不显著外,其他性状品种间和年份间均呈显著的差异,且2年变化趋势相同。有效分枝数变异幅度最大,其次是主茎荚数、单株粒重和株高,这些性状选择潜力较大,品质性状的变异幅度较小,选择潜力有限;(2)表型性状特征频率分布均符合正态分布。受育成单位纬度和育种目标的影响,生育期呈现北早南晚,北部育成品种营养体较小、植株矮小、节数相对较少、脂肪含量较高,南部育成品种营养体较大、植株高大、单株有效节数多且主茎单节最多荚数多,部分品种蛋白质含量相对较高;(3)采用主成分分析方法综合评价表明,吉育71的ZF值最高,综合性状表现最好,表型性状与ZF值相关分析结果显示,生育期、株高、主茎节数、地上部生物产量、收获指数、主茎荚数和主茎单节最多荚数等7个表型性状可作为春大豆种质资源综合评价指标。在大豆育种中应重视利用具有丰富遗传多样性的基因资源,在亲本选配时适当选择综合性状优良、育种性状优势互补的种质。     

四川省小麦育成品种系谱分析及发展进程

品种系谱蕴含亲本来源、选育方式、亲缘关系等大量信息,对揭示农作物品种演变特点、规律并最终指导育种实践具有重要意义。本文汇总了四川省1936～2017年间326个小麦品种的系谱信息,对育种方式、亲本构成、高频亲本及骨干亲本的变化、遗传贡献、易位系及人工合成种质分布等情况进行了梳理与分析。从20世纪30年代至今,四川省育种家从大量材料中选用387个直接亲本,采用杂交育种等方式,配制数千个组合,从256个组合中选育出314个品种,对四川省小麦生产做出了重要贡献,同时也为小麦育种提供了更为优异的材料基础。四川省小麦育种经历了从无到有,从主要依靠引进材料、地方品种到自主创制材料的过程;高频亲本、骨干亲本随育种进程推进而逐渐变化。易位系和人工合成种质对四川省小麦育种贡献巨大。育种目标的一致性必然导致遗传多样性散失和遗传基础脆弱,今后重点应加强资源的创制、保护和利用。本文通过育成品种的系谱梳理,对四川省小麦的育种发展进程进行了分析,以期为未来种质资源的收集创制和育种研究提供重要参考信息。     

芝麻核心收集品中育成品种（系）的遗传多样性分析

利用SRAP分子标记技术对中国芝麻核心收集品的育成品种(系)进行遗传多样性分析,结果表明,14对引物组合在18份芝麻育成品种(系)间共扩增出稳定清晰的条带193条,其中多态性带124条,占64.2%.通过聚类分析和主坐标分析,表明育成品种(系)的遗传基础存在一定的多样性,但遗传相似系数较大(0.5342～0.9688),遗传距离较近.该研究结果表明,在芝麻育种的亲本选配中应积极引入地方种质、国外种质等,以拓宽遗传基础.     

东北地区谷子地方品种和育成品种表型比较分析

我国东北地区谷子育种经历了从地方品种到育成品种的转变,但其具体表型性状等变化尚不清楚。本研究在敖汉旗对我国东北地区120个谷子地方品种和育成品种进行表型鉴定,并分析了遗传多样性,结果表明:东北地区谷子品种以绿幼苗、绿叶鞘、纺锤松散穗、黄粒、黄米型为主。育成品种晚熟、生物量大且高产,表现在出苗至抽穗、开花、成熟的时间以及播种至成熟的时间均极显著大于地方品种;主茎直径、叶片数、旗叶宽度均极显著大于地方品种;主穗重、主穗粒数极显著大于地方品种,主穗粒重和产量显著大于地方品种,但千粒重极显著小于地方品种,说明育成品种主要通过增加穗粒数来实现产量提升。遗传多样性指数分析发现,参试品种各性状遗传多样性指数大小顺序为:产量性状(2.0063)形态性状(1.9655)生育期(1.7238)质量性状(0.6370);地方品种护颖颜色、粒色、米色遗传多样性指数明显高于育成品种,说明谷子育种使粒色米色越来越趋于一致。基于30个性状的标准化数据,将参试品种聚为两类,聚类结果与品种来源地没有明显关联。类群Ⅰ为早熟、低产品种,且幼苗叶色、米色均为绿色和黄色;类群Ⅱ为晚熟、高产品种。根据10个主要表型性状,筛选出综合性状优良的红谷子、燕谷18等种质资源,可供东北地区谷子育种重点利用。     

论我国棉花育种的基础种质

自1918年我国引进美国脱字棉开始,到2000年止,我国共育成陆地棉品种1376个,海岛棉品种59个.按系谱及优良种质衍生品种的数量分析,我国品种可追溯到54个基础种质,其中海岛棉7个.按照引进时间和育成年限,可将陆地棉分三期基础种质,海岛棉分为二期基础种质.近百年来,这些基础种质对我国棉花育种和生产发展起了非常重要的作用.     

大豆优异种质资源的利用与创新

黑龙江省农科院利用已获得的具有野生大豆(含半野生大豆)多花荚、多分枝、高蛋白等有益性状基因的优异种间杂交新种质(G.max×G.soja)与栽培大豆(G.max)回交,一方面继续拓宽大豆育种遗传基础,另一方面改善现有种间杂交种质的农艺性状和品质,并提高产量水平,已选育出外贸制纳豆、豆芽、制酱及青瓤黑豆等特用大豆品种(系).实践表明,利用野生大豆及种间杂交新种质,对拓宽大豆育种遗传基础,提高大豆育成品种水平,尤其对特用大豆品种(系)的选育是有效可行的.     

Genetic relationships and structure among open-pollinated maize varieties adapted to eastern and southern Africa using microsatellite markers

Molecular characterization of open-pollinated maize varieties (OPVs) is fundamentally important in maize germplasm improvement. We investigated the extent of genetic differences, patterns of relationships, and population structure among 218 diverse OPVs widely used in southern and eastern Africa using the model-based population structure, analysis of molecular variance, cluster analysis, principal component analysis, and discriminant analysis. The OPVs were genotyped with 51 microsatellite markers and the fluorescent detection system of the Applied Biosystems 3730 Capillary Sequencer. The number of alleles detected in each OPV varied from 72 to 155, with an overall mean of 127.6. Genetic distance among the OPVs varied from 0.051 to 0.434, with a mean of 0.227. The different multivariate methods suggest the presence of 2–4 possible groups, primarily by maturity groups but also with overlapping variation between breeding programs, mega-environments, and specific agronomic traits. Nearly all OPVs in group 1 and group 2 belong to the intermediate-late and early maturity groups, respectively. Group 3 consisted of mainly intermediate maturing OPVs, while group 4 contained OPVs of different maturity groups. The OPVs widely used in eastern Africa either originated from the southern African maize breeding programs, or the majority of inbred lines used as parents by the two breeding programs in developing the OPVs might be genetically related. Some of the OPVs are much older than others, but they still did not show a clear pattern of genetic differentiation as compared with the recently developed ones, which is most likely due to recycling of the best parental lines in forming new OPVs.     

Trends in genetic diversity among European maize cultivars and their parental components during the past 50 years

It has been claimed that the system that delivers the products of plant breeding reduces the diversity of cultivated varieties leading to an increased genetic vulnerability. The main goal of our study was to monitor the temporal trends in genetic diversity over the past five decades among maize cultivars with the largest acreage in Central Europe. Our objectives were to (1) investigate how much of the genetic diversity present in important adapted open-pollinated varieties (OPVs) has been captured in the elite flint germplasm pool, (2) examine changes in the genetic diversity among the most important commercial hybrids as well as in their dent and flint parents, (3) analyze temporal changes in allele frequencies between the dent and flint parental inbreds, and (4) investigate linkage disequilibrium (LD) trends between pairs of loci within the set of parental dent and flint lines. We examined 30 individuals of five prominent OPVs from Central Europe, 85 maize hybrids of economic importance, and their dent and flint parental components with 55 SSRs. LD was significant at probability level P=0.01 for 20.2% of the SSR marker pairs in the 82 dent lines and for 17.2% in the 66 flint lines. The dent and flint heterotic groups were clearly separated already at the beginning of hybrid breeding in Central Europe. Furthermore, the genetic variation within and among varieties decreased significantly during the five decades. The five OPVs contain numerous unique alleles that were absent in the elite flint pool. Consequently, OPVs could present useful sources for broadening the genetic base of elite maize breeding germplasm.     

Grouping of tropical mid-altitude maize inbred lines on the basis of yield data and molecular markers

The classification of maize inbred lines into heterotic groups is an important undertaking in hybrid breeding. The objectives of our research were to: (1) separate selected tropical mid-altitude maize inbred lines into heterotic groups based on grain yield data; (2) assess the genetic relationships among these inbred lines using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers; (3) examine the consistency between yield-based and marker-based groupings of the inbred lines. Thirty-eight tropical mid-altitude maize inbred lines were crossed to two inbred line testers representing the flint and dent heterotic pattern, respectively. The resulting testcrosses were evaluated in a trial at three locations for 2 years. Significant general combining ability (GCA) and specific combining ability (SCA) effects for grain yield were detected among the inbred lines. The tester inbred lines classified 23 of the 38 tested inbred lines into two heterotic groups based on SCA effects and testcross mean grain yields. This grouping was not related to endosperm type of the inbred lines. The outstanding performance of testcrosses of the remaining 15 inbred lines indicates the presence of significant genetic diversity that may allow the assignment of the lines into more than two heterotic groups. Diversity analysis of the 40 maize inbred lines using AFLP and SSR markers found high levels of genetic diversity among these lines and subdivided them into two main groups with subdivision into sub-groups consistent with breeding history, origin and parentage of the lines. However, heterotic groups formed using yield-based combining ability were different from the groups established on the basis of molecular markers. Considering the diversity of the genetic backgrounds of the mid-altitude inbred lines, the marker-based grouping may serve as the basis to design and carry out combining ability studies in the field to establish clearly defined heterotic groups with a greater genetic similarity within groups.Communicated by H.H. Geiger     

Genomic-based-breeding tools for tropical maize improvement

Maize has traditionally been the main staple diet in the Southern Asia and Sub-Saharan Africa and widely grown by millions of resource poor small scale farmers. Approximately, 35.4 million hectares are sown to tropical maize, constituting around 59% of the developing worlds. Tropical maize encounters tremendous challenges besides poor agro-climatic situations with average yields recorded <3 tones/hectare that is far less than the average of developed countries. On the contrary to poor yields, the demand for maize as food, feed, and fuel is continuously increasing in these regions. Heterosis breeding introduced in early 90 s improved maize yields significantly, but genetic gains is still a mirage, particularly for crop growing under marginal environments. Application of molecular markers has accelerated the pace of maize breeding to some extent. The availability of array of sequencing and genotyping technologies offers unrivalled service to improve precision in maize-breeding programs through modern approaches such as genomic selection, genome-wide association studies, bulk segregant analysis-based sequencing approaches, etc. Superior alleles underlying complex traits can easily be identified and introgressed efficiently using these sequence-based approaches. Integration of genomic tools and techniques with advanced genetic resources such as nested association mapping and backcross nested association mapping could certainly address the genetic issues in maize improvement programs in developing countries. Huge diversity in tropical maize and its inherent capacity for doubled haploid technology offers advantage to apply the next generation genomic tools for accelerating production in marginal environments of tropical and subtropical world. Precision in phenotyping is the key for success of any molecular-breeding approach. This article reviews genomic technologies and their application to improve agronomic traits in tropical maize breeding has been reviewed in detail.     

Evaluating genetic relationships between tropical maize inbred lines by means of AFLP profiling

Diversity among tropical maize inbred lines that compose breeding programs, is not well known. The lack of this information has made the arrangement of heterotic groups to be used for breeding purposes difficult. Methods of molecular analysis have been used as efficient alternatives for evaluating genetic diversity, aiming at heterotic group arrangement and acquisition of new hybrids. In this study, AFLP (amplified fragment length polymorphism) was used to investigate the genetic relationships among 96 tropical maize inbred lines from two different origins. The polymorphism level among the genotypes and the possibility of their allocation in heterotic groups were evaluated. Besides, correlations among genetic diversity and flowering time were analyzed. Nine primer combinations were used to obtain AFLP markers, producing 638 bands, 569 of which were polymorphic. Genetic similarities (GS), determined by Jaccard's similarity coefficient, varied from 0.345 to 0.891, with an average of 0.543. The dendrogram based on the GS and on the UPGMA cluster method did not separate the inbred lines in well-defined groups. Aiming at separating the lines into more accurate groups, Tocher's optimization procedure was carried out, 17 groups being identified. Association between flowering time and germplasm pools was detected. AFLP showed itself to be a robust assay, revealing a great power of detection of genetic variability in the tropical germplasm, and also demonstrated to be very useful for guiding breeding programs.     

Molecular marker-assisted breeding options for maize improvement in Asia

Maize is one of the most important food and feed crops in Asia, and is a source of income for several million farmers. Despite impressive progress made in the last few decades through conventional breeding in the “Asia-7” (China, India, Indonesia, Nepal, Philippines, Thailand, and Vietnam), average maize yields remain low and the demand is expected to increasingly exceed the production in the coming years. Molecular marker-assisted breeding is accelerating yield gains in USA and elsewhere, and offers tremendous potential for enhancing the productivity and value of Asian maize germplasm. We discuss the importance of such efforts in meeting the growing demand for maize in Asia, and provide examples of the recent use of molecular markers with respect to (i) DNA fingerprinting and genetic diversity analysis of maize germplasm (inbreds and landraces/OPVs), (ii) QTL analysis of important biotic and abiotic stresses, and (iii) marker-assisted selection (MAS) for maize improvement. We also highlight the constraints faced by research institutions wishing to adopt the available and emerging molecular technologies, and conclude that innovative models for resource-pooling and intellectual-property-respecting partnerships will be required for enhancing the level and scope of molecular marker-assisted breeding for maize improvement in Asia. Scientists must ensure that the tools of molecular marker-assisted breeding are focused on developing commercially viable cultivars, improved to ameliorate the most important constraints to maize production in Asia.     

Identifying loci with breeding potential across temperate and tropical adaptation via EigenGWAS and EnvGWAS

Understanding the genomic basis of adaptation in maize is important for gene discovery and the improvement of breeding germplasm, but much remains a mystery in spite of significant population genetics and archaeological research. Identifying the signals underpinning adaptation are challenging as adaptation often coincided with genetic drift, and the base genomic diversity of the species in massive. In this study, tGBS technology was used to genotype 1,143 diverse maize accessions including landraces collected from 20 countries and elite breeding lines of tropical lowland, highland, subtropical/midaltitude and temperate ecological zones. Based on 355,442 high‐quality single nucleotide polymorphisms, 13 genomic regions were detected as being under selection using the bottom‐up searching strategy, EigenGWAS. Of the 13 selection regions, 10 were first reported, two were associated with environmental parameters via EnvGWAS, and 146 genes were enriched. Combining large‐scale genomic and ecological data in this diverse maize panel, our study supports a polygenic adaptation model of maize and offers a framework to enhance our understanding of both the mechanistic basis and the evolutionary consequences of maize domestication and adaptation. The regions identified here are promising candidates for further, targeted exploration to identify beneficial alleles and haplotypes for deployment in maize breeding.     

Molecular marker assisted broadening of the Central European heterotic groups in rye with Eastern European germplasm

Broadening the genetic base of heterotic pools is a key to ensure continued genetic gains in hybrid breeding and extend hybrid cultivation to new areas. In the present study, two Central European heterotic pools (Carsten and Petkus) and five Eastern European open-pollinated varieties (OPVs, Pop-1 to Pop-5) were studied with the objectives to (1) investigate the genetic diversity in OPVs and the heterotic pools using molecular and field data, (2) evaluate the molecular diversity among OPVs, (3) examine the combining ability for grain yield of the OPVs when crossed with testers in field trials, and (4) develop a strategy for targeted introgression of OPV germplasm into the heterotic pools. In total, 610 S₀ plants, 347 from OPVs and 263 from heterotic pools, were developed. Clones of the S₀ plants of OPVs were crossed with two testers belonging to each heterotic pool, while clones of heterotic pools were crossed with only the opposite tester. Testcrosses were evaluated for grain yield in multi-location trials. In addition, 589 S₀ plants were fingerprinted with 30 SSR markers. The data revealed that the Carsten pool has a narrow genetic base and should be the primary target for broadening the established heterotic pattern. Mean and genetic variance suggested that Pop-2 and Pop-4 are good candidates for introgression in Petkus pool and Pop-5 in Carsten pool. Nevertheless, introgression of Pop-5 in Carsten could reduce the genetic diversity between heterotic pools. Therefore, we suggest that either selected plants of Pop-5 should be introgressed or more Eastern European germplasm should be fingerprinted and field evaluated to identify promising germplasm for broadening the established heterotic pattern.     

Interpreting genotype × environment interaction in tropical maize using linked molecular markers and environmental covariables

An understanding of the genetic and environmental basis of genotype×environment interaction (GEI) is of fundamental importance in plant breeding. In mapping quantitative trait loci (QTLs), suitable genetic populations are grown in different environments causing QTLs×environment interaction (QEI). The main objective of the present study is to show how Partial Least Squares (PLS) regression and Factorial Regression (FR) models using genetic markers and environmental covariables can be used for studying QEI related to GEI. Biomass data were analyzed from a multi-environment trial consisting of 161 lines from a F_3:4 maize segregating population originally created with the purpose of mapping QTLs loci and investigating adaptation differences between highland and lowland tropical maize. PLS and FR methods detected 30 genetic markers (out of 86) that explained a sizeable proportion of the interaction of maize lines over four contrasting environments involving two low-altitude sites, one intermediate-altitude site, and one high-altitude site for biomass production. Based on a previous study, most of the 30 markers were associated with QTLs for biomass and exhibited significant QEI. It was found that marker loci in lines with positive GEI for the highland environments contained more highland alleles, whereas marker loci in lines with positive GEI for intermediate and lowland environments contained more lowland alleles. In addition, PLS and FR models identified maximum temperature as the most-important environmental covariable for GEI. Using a stepwise variable selection procedure, a FR model was constructed for GEI and QEI that exclusively included cross products between genetic markers and environmental covariables. Higher maximum temperature in low- and intermediate-altitude sites affected the expression of some QTLs, while minimum temperature affected the expression of other QTLs. Received: 10 January 1999 / Accepted: 12 March 1999     

玉米重要自交系的肿囊腐霉茎腐病抗性鉴定与评价

由肿囊腐霉菌(Pythium inflatum Matthews)引起的玉米茎腐病是影响玉米产量的一种重要病害。为进一步拓展可利用的抗源,于2010-2011年在田间采用人工接种方法对287份重要的玉米自交系种质进行了玉米茎腐病的抗性鉴定评价。结果表明,287份鉴定材料中有171份自交系对茎腐病的抗性达到中抗以上水平,占鉴定材料的59.58%,其中高抗自交系共43份,占鉴定材料总数的14.98%;感病类型自交系共116份,占鉴定材料的40.42%,其中高感自交系共95份,占鉴定材料总数的33.10%。Lancaster、Reid及P群种质中具有丰富的茎腐病抗源,而塘四平头种质群中茎腐病抗源相对缺乏,多为感病类型。该研究结果可为今后我国玉米茎腐病抗性种质的引进和改良提供重要参考。