玉米花期性状的全基因组关联分析

花期性状是玉米的重要性状,与熟期、散粉结实率和产量关系密切,对玉米品种选育至关重要。为探究玉米花期性状的遗传基础,本研究以248份遗传多样性丰富的玉米自交系作为关联群体,通过2017年和2018年在河北保定和辛集的田间试验调查抽雄期、散粉期、吐丝期和散粉吐丝间隔期4个花期相关性状,利用分布于全基因组的83057个SNP标记进行关联分析。结果表明,4个花期相关性状的基因型、年份、地点、基因型与地点的互作、基因型与年份的互作均达到极显著水平;抽雄期、散粉期、吐丝期的遗传率分别为71.77%、71.27%、73.93%,并且两两性状间呈极显著正相关,散粉吐丝间隔期遗传率为62.50%,仅与吐丝期呈极显著正相关;4个花期性状共检测到18个SNPs-性状关联(共涉及16个SNP位点),单个位点的表型贡献率范围为5.46%~28.36%,仅1个位点在不同性状中检测到;筛选到81个候选基因,其中36个在GO分析中具有功能注释。潜在候选基因GRMZM5G877647编码early flowering 4蛋白,参与光周期的调节;GRMZM2G173630编码类赤霉素受体蛋白参与植物激素信号转导;GRMZM2G001139、GRMZM2G375707编码与花器官建成的MADS转录因子。这些潜在候选基因为解析玉米花期性状遗传基础和分子辅助选择育种提供参考。     

玉米生育期QTL定位及上位性互作效应的遗传研究

为了探讨玉米生育期的遗传规律,以自交系N6和BT-1为亲本组配了重组自交系(Recombinant inbred line,RIL)群体,利用207个微卫星标记构建分子标记遗传连锁图谱,对生育期相关的抽雄、吐丝和散粉3个性状进行QTL定位,并进行上位性效应分析。结果表明,在第1染色体umc1676-umc1590区域和第2染色体的umc1422-umc1776区域存在共同控制抽雄、吐丝和散粉3个性状的稳定的QTL位点。生育期3个性状QTL的上位性分析,都检测到3对加性×加性上位性互作效应,分别可以解释3.78%~5.43%,1.24%~2.36%和3.27%~4.04%的表型遗传变异。上位性效应是生育期性状的重要遗传基础。     

异地种植对微胚乳玉米主要性状的影响研究

在广西南宁、山西平遥两个地点分别种植16个微胚乳玉米杂交组合,观测了主要农艺性状和产量性状,同时估算了这些重要性状的广义遗传率。结果如下:(1)抽雄期、散粉期、吐丝期、株高和穗位高5个性状,在山西平遥所有组合的值都高于广西南宁;穗长、穗粒重和百粒重3个性状则是山西平遥所有组合的值都低于广西南宁;穗粗则随组合而异。(2)两地各性状的广义遗传率相差较大的有抽雄期、散粉期、吐丝期、穗长和百粒重。一年多点联合方差分析广义遗传率比单一地点分析都高的有株高、穗粗、穗粒重和百粒重。     

孕穗期高温逆境对玉米杂交种的影响分析

为了筛选和分析耐高温逆境能力强的夏玉米品种,利用智能温室在玉米孕穗期模拟高温气象,研究分析孕穗期高温逆境对10个夏玉米杂交种的植株性状、穗部性状、花期、可育率和理论产量等指标的影响。结果表明,高温逆境使孕穗期玉米的株高和穗位高变高,抽雄期、吐丝期和散粉期滞后,抽雄至散粉间隔期缩短,雌雄间隔期延长,穗长、穗粗、穗行数、行粒数、穗粒数、穗粒重、可育率和理论产量下降。通过对不同玉米品种在孕穗期高温逆境下的性状表现及其变化的差异分析和聚类分析,试验品种的耐高温热害能力由强到弱表现为：漯玉336>漯玉16>阳光98>郑单958>豫丰3358>先玉335>阳光99>漯青19>漯玉172>漯玉171。     

黄淮海玉米自交系氮利用效率相关性状分析

为了阐明不同玉米自交系间氮效率差异特征,筛选优异的氮高效种质,改良玉米的氮素利用效率,为玉米氮高效育种方面的研究奠定基础.以平均产量和氮效率为评价指标并结合抽雄期、散粉期、成熟期、株高、穗位等二级性状,对25份目前在黄淮海应用的核心种质和自育玉米自交系材料进行相关性分析及氮利用效率评价.相关性分析结果表明,氮效率在2种不同的氮处理条件下与散粉-吐丝间隔期、平均产量都呈极显著正相关,与株高分别呈显著和极显著正相关,即3个性状可作为评价玉米自交系材料氮效率高低的指标.方差分析结果显示,在低氮和高氮条件下,散粉-吐丝间隔期、平均产量及株高均存在极显著的差异.将高氮条件与低氮条件下的平均产量进行分析并结合株高和散粉-吐丝间隔期等二级性状,鉴定出郑58、WK858和9058这3个玉米自交系材料可在氮高效育种中作为供体亲本来改良玉米的氮素利用效率.丰富了氮高效种质资源,评价了不同玉米材料的氮素利用效率,揭示了不同材料对氮素的反应程度,为氮高效育种提供材料以及自交系的选育和合理的利用肥料提供理论基础和技术支撑.     

玉米制种中三类苗的影响及预防

玉米制种中三类苗的出现,将对制种纯度有很大的影响,而且也影响到产量和品质.因为三类苗在抽雄期间不可能与其它正常株同时进行,这样就会造成漏抽、或者抽时因株型过于瘦小而抽断雄穗,这些在田检抽雄后都会成为散粉株形成自交从而降低田间纯度.即使是抽雄时很仔细很干净、也会因个体发育瘦小,雌穗吐丝过慢而与父本花期不能完全相遇,造成授粉不完全、花穗、空穗率高,授粉子粒形成也会是小子粒或异型不正常子粒.     

杂交玉米制种花期预测方法与调整措施

玉米杂交制种的成败,关键在于父母本花期能否良好相遇.通过多年的生产实践证明,花期良好相遇的理想标准应为"母本雌穗已经开始吐丝、父本雄穗即将散粉".这样可以保证在母本花丝受粉能力最强时,一期父本处在散粉盛期,二期父本也开始散粉,从而获得充足的花粉,提高制种产量.     

水分胁迫对甜玉米主要农艺性状及产量的影响

在大棚内采用人工供水的方法,研究不同水分胁迫下甜玉米品种主要农艺性状与产量的关系。结果表明,轻度干旱胁迫下可用株高、茎粗、散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、千粒重等6个性状耐旱系数作为品种耐旱性鉴定的指标,而中度干旱胁迫下可用穗位叶面积、散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、出籽率、千粒重这6个性状耐旱系数预测品种产量的耐旱系数。在不同程度水分胁迫下,散粉至吐丝间隔期(ASI)、穗粗、每穗粒数、千粒重等4个性状耐旱系数是不同品种耐旱性鉴定的重要指标,除此之外,株高、茎粗、穗位叶面积等决定植株形态的性状指标也对甜玉米耐旱性起一定作用。     

对玉米杂交制种花期不遇的原因、花期预测及花期调节的探讨

是指母本吐丝期与父本抽雄散粉期相遇不良或不能相遇，影响母本授粉结实，造成制种减产甚至失败的情况。     

广东甜玉米不同品种耐旱性鉴定试验

采用塑料大棚遮挡自然降水的方法研究了不同水分胁迫下8个甜玉米品种散粉至吐丝间隔期（ASI）、营养器官和产量构成因素性状指标的变化。结果表明，在干旱胁迫下，各品种的散粉至吐丝间隔期（ASI）受到不同程度的延迟，营养器官和产量构成因素性状指标呈下降趋势。轻度干旱对各甜玉米品种上述性状的影响较小，中度干旱对其影响比较大，与正常水分条件相比部分品种受到的影响达到显著或极显著的差异。以散粉至吐丝间隔期（ASI）、产量及产量的耐旱系数为主并结合营养器官形态性状和产量构成因素进行耐旱性综合评价较为可行。粤甜13号和正甜38号耐旱性相对较好，在生产中可作为耐旱节水型的品种加以应用。     

陆地棉重组自交系群体纤维品质及产量性状遗传变异分析

以陆地棉优质品系0-153和大面积推广的双价转基因抗虫棉品系sGK9708为亲本构建了含有196个F6:8家系的重组自交系群体。在4个环境中,纤维长度、纤维强度、麦克隆值、伸长率、整齐度指数、单株结铃数、铃重、衣分、子指、单株子棉产量及单株皮棉产量等性状均呈正态分布,且存在双向超亲分离。多环境下变异分析表明,各性状家系间及环境间存在极显著差异。除纤维伸长率外,其余各纤维品质及产量性状都具有较高的遗传力,在0.75以上。共有6个家系在纤维长度、细度和强度性状上均超过高亲,可作为优质纤维种质。相关分析显示,有些家系可能打破了纤维品质和产量性状间的负相关。通过聚类分析得出,该群体各系分在了不同的组,表明存在着一定的遗传差异。该群体是进行优异纤维品质相关基础研究的良好材料。     

Dissection of the genetic architecture for grain quality‐related traits in three RIL populations of maize (Zea mays L.)

To manipulate the composition of the maize kernel to meet future needs, an understanding of the molecular regulation of kernel quality‐related traits is required. In this study, the quantitative trait loci (QTL) for the concentrations of grain protein, starch and oil were identified using three sets of RIL populations in three environments. The genetic maps and the initial QTL were integrated using meta‐analyses. A total of 38 QTL were identified, including 15 in population 1, 12 in population 2 and 11 in population 3. The individual effects ranged from 2.87% to 13.11% of the phenotypic variation, with seven QTL each contributing over 10%. One common QTL was found for the concentrations of grain protein and starch in bin 3.09 in the three environments and the three RIL populations. Of the 38 initial QTL, 22 were integrated into eight mQTL by meta‐analysis. mQTL3 and mQTL8 of the key mQTL in which the initial QTL displayed R² > 10% included six and three initial QTL for grain protein and starch concentrations from two or three populations, respectively. These results will provide useful information for marker‐assisted selection to improve the quality of the maize kernel.     

不同密度下玉米穗部性状的QTL分析

为研究玉米穗部性状对不同种植密度的遗传响应,以郑58和HD568为亲本构建的220个重组自交系群体为材料,于2014年春、2014年冬及2015年春分别在北京和海南进行3个种植密度的田间试验,调查玉米穗长、穗粗、穗行数和行粒数等表型性状。利用SAS软件计算穗部性状的最优线性无偏估计值(BLUP),并采用完备区间作图法进行QTL定位。结果表明,在3个种植密度下共检测到42个QTL,单个QTL可解释4.20%~14.07%的表型变异。3个种植密度下同时检测到位于第2染色体上控制穗行数的QTL。2个种植密度下同时检测到4个与穗粗、穗行数和行粒数有关的QTL,其中第4染色体上1个与穗行数有关的主效QTL,在低、中种植密度下可分别解释表型变异的10.88%和14.07%。此外,在第2、4和9染色体上检测到3个同时调控不同穗部性状的QTL。研究结果表明玉米穗部性状在不同种植密度下的遗传调控发生变化,在不同密度下共同检测到的稳定QTL可应用于精细定位或开发玉米耐密性分子标记用于辅助育种。     

基于高密度遗传图谱的玉米籽粒性状QTL定位

籽粒大小及百粒重是决定玉米产量的重要因素。为解析籽粒性状遗传基础,本研究以玉米自交系黄早四(HZS)和Mo17为亲本,构建包含130个重组自交系(recombination inbred line,RIL)的RIL群体。基于GBS(genotypingby-sequencing)技术获得的高密度多态性SNP(single nucleotide polymorphism)位点,构建了包含1262个Bin标记的高密度遗传图谱。采用完备区间作图法,对5个环境条件下的粒长、粒宽、百粒重、粒长/粒宽4个性状分别进行QTL(quantitative trait locus)定位,共检测到30个QTL。利用5个环境性状均值,共检测到11个QTL。其中粒长主效QTL qklen1、粒长/粒宽主效QTL qklw1在3个单环境条件下均被检测到,且定位在第1染色体相邻区域,物理位置分别为210~212 Mb、207~208 Mb,表型贡献率分别为22.60%和26.79%,被认为是控制玉米籽粒形状的主效位点。针对第1染色体207~212 Mb区间,采用成组法t检验,对黄早四(受体)和Mo17(供体)构建的BC3F1回交群体进行单标记分析。结果表明,在BC3F1群体中qklen1和qklw1同样具有显著的遗传效应。本研究结果不仅为分子标记辅助选择籽粒性状提供了实用标记,而且为主效基因的进一步精细定位和候选基因挖掘奠定了基础。     

Genetic dissection of plant height by molecular markers using a population of recombinant inbred lines in maize

Plant height is an important trait for maize breeding because it is related to planting density and lodging resistance. It is influenced by many qualitative genes and quantitative trait loci (QTL). In this study, the genetic basis of plant height and its related traits were dissected, using simple sequence repeat (SSR) markers with a maize population of 294 recombinant inbred lines (RIL). Correlation results showed that plant height had a significant positive correlation with leaf number, average internode length and internode number. Increased plant height was affected most by average internode length. Six QTL for plant height were detected, which were consistent with those reported in previous studies. Moreover, eight QTL for leaf number, seven for internode number and six for average internode length were identified. Four of six QTL detected for average internode length were located on the same chromosomal region as the QTL affecting plant height and shared common molecular markers. This latter result strongly suggests that average internode length was the main contributor to plant height in maize.     

基于多重相关RIL群体的玉米株高和穗位高QTL定位

株高和穗位高是玉米育种中的重要农艺性状。本研究利用我国玉米育种中骨干亲本黄早四与来自不同杂种优势群的其他11个骨干自交系组配11个RIL群体,开展基于单环境、联合环境的QTL分析,分别检测到269个和176个QTL。通过区段整合,检测到21个株高主效QTL及15个穗位高主效QTL,这些QTL分布在第1、第2、第3、第6、第7、第8、第9、第10染色体上。相对于共同亲本黄早四而言,部分QTL在不同RIL群体中的效应方向一致,来自共同亲本黄早四的等位基因在不同群体中能够稳定地表达。同时,还分别定位到在多环境下稳定表达的5个株高、4个穗位高“环境钝感QTL”。此外,进一步鉴定出5个重要的株高和穗位高QTL富集区段(bin 1.01-1.02,1.08-1.11,3.05,8.03-8.05和9.07),这些区段均包含多个株高和穗位高相关QTL,如bin3.05位点包含7个QTL,bin8.03-8.05位点分别包含9个QTL,且这些QTL至少在3个不同环境中能够被检测到,这些区域对QTL的精细定位和克隆有重要参考价值。     

Quantitative trait locus mapping for seed artificial aging traits using an F2:3 population and a recombinant inbred line population crossed from two highly related maize inbreds

Quantitative trait locus (QTL) mapping for seed longevity is essential for breeding modern cultivars with resistance to deterioration during postharvest storage. The inbred lines X178 and I178 showed large differences in seed vigour after artificial aging treatment, while they had similar performances in terms of most agronomic traits. An F_2:3 population and a recombinant inbred line (RIL) population were generated to map QTL after 5 days under artificial aging conditions. Positive correlations were observed among all investigated traits including the aging germination rate, relative aging germination rate, aging simple vigour index, aging primary root length, aging shoot length and aging total length. Thirteen QTL were identified to locate on five chromosome regions: Chr.1:297 Mb (chromosome 1 region 297 Mb), Chr.3:205 Mb, Chr.4:240 Mb, Chr.5:205 Mb and Chr.7:155 Mb, with 2 to 4 QTL co‐located on a region. In each region, 3–8 previously identified aging‐related QTL were located, confirming the importance of these regions for controlling seed longevity in different maize populations. Taken together, the results of this work provide a foundation for further QTL fine mapping and the molecular‐assisted breeding of aging tolerant maize.     

抗青枯病兼大果和高出仁率的花生新种质创制

青枯病是影响花生产量和品质的重要土传性细菌病害,百果重和出仁率是与花生产量相关的重要性状。本研究利用远杂9102和徐州68-4杂交构建的RIL群体,在B02染色体上定位到青枯病抗性主效QTL qBWRB02。结合前期对百果重和出仁率QTL的定位结果发现,所涉及的3个性状的主效QTL分布在不同的染色体上。以RIL群体基因型数据和多个环境的青枯病抗性、百果重和出仁率表型数据为基础,利用与主效QTL紧密连锁分子标记筛选出6份聚合抗青枯病、荚果大、出仁率高3种优良性状的新种质,可以作为育种中间材料或亲本培育高产抗病新品种。本研究利用分子标记辅助选择和表型鉴定相结合有效筛选抗病高产种质,为未来花生育种提供了新思路。     

Co-location of seed oil content,seed hull content and seed coat color QTL in three different environments in <Emphasis Type="Italic">Brassica napus</Emphasis> L.

Increasing seed oil content is an important breeding goal for Brassica napus L. (B. napus). The identification of quantitative trait loci (QTL) for seed oil content and related traits is important for efficient selection of B. napus cultivars with high seed oil content. To get better knowledge on these traits, a molecular marker linkage map for B. napus was constructed with a recombinant inbred lines (RIL) population. The length of the map was 1,589 cM with 451 markers distributed over 25 linkage groups. QTL for seed oil content, seed hull content and seed coat color in three environments were detected by composite interval mapping (CIM) tests. Eleven QTL accounted for 5.19–13.57% of the variation for seed oil content. Twelve QTL associated with seed hull content were identified with contribution ranging from 5.80 to 22.71% and four QTL for seed coat color accounted for 5.23–15.99% of the variation. It is very interesting to found that co-localization between QTL for the three traits were found on N8. These results indicated the possibility to combine favorable alleles at different QTL to increase seed oil content, as well as to combine information about the relationship between seed oil content and other traits.     

Dynamic QTL mapping for plant height in Upland cotton (Gossypium hirsutum)

Plant height served as one of model traits to analyse dynamic development. The objective of this research was to investigate quantitative trait loci (QTL) and dynamic QTL for plant height trait using an intraspecific recombinant inbred line (RIL) population and a constructed genetic map in Upland cotton (Gossypium hirsutum L.). Totally, 41 QTL and 23 conditional QTL controlling plant height were detected at two experimental environments, respectively. Four stable QTL were identified simultaneously in both environments. Some QTL identified at the early stage could not be detected at the final stage at plant maturity. Conditional QTL with different genetic effects were identified at certain stages, demonstrating that the expression of QTL had temporal characteristic during plant growth. Therefore, the study of dynamic QTL could unravel temporal genetic patterns controlling complex developmental quantitative traits.