基于GGE双标图对江苏省大麦鉴定试验品种的高产稳产和适应性分析

以2014~2015年江苏省大麦鉴定试验的14个品种在8个试验点的产量数据为材料,采用GGE双标图法分析参试品种的高产、稳产和区域适应性。基于对试验点的区分力和代表性分析发现,尽管各个试验点在区分力方面存在一定的差异,但均具有较强的代表性。通过对参试品种的高产性和稳产性分析,发现苏B1202和连啤9091在区域试验中具有较好的高产性和稳产性,且适宜种植的试验点较多,具有一定的广适性,是大麦生产上具备推广潜力的理想品种。

基于GGE双标图和AMMI模型对江苏省水稻区试品种的丰产性和稳定性分析

本研究综合利用GGE双标图方法和AMMI模型对2017年江苏省杂交中粳稻区域试验的12个参试品种的丰产性和稳产性进行了分析。结果表明,基因型、环境及基因型与环境互作效应对杂交中粳稻产量有极显著的影响。在所有参试品种中,杂中区03和杂中区12是丰产稳产的广适性品种,可在粳稻适区进行推广。江苏徐淮地区淮阴农业科学研究所试点代表性最强,而江苏欢腾农业有限公司试点的鉴别力最强。AMMI和GGE双标图的综合运用,可准确直观地评价各品种的丰产性、稳定性和适应性以及各试点的鉴别力和代表性。

基于GGE双标图对江苏省杂交晚粳品种区域试验的评价分析

利用GGE双标图方法对江苏省2017年杂交晚粳组区试中14个品种的多点测试数据进行分析。基于试验点的区分力和代表性分析,发现此次区试的6个试验点均具有较强代表性。GGE双标图高产、稳产性结果显示甬优1526产量最高,其次是甬优7826、春优312;浙粳优7172稳产性最强,其次是春优312。理想品种分析结果显示甬优1526为最理想品种,既高产又稳产。这说明GGE双标图可有效且直观地评估和解释新品种的区试结果。

花生收获前黄曲霉毒素污染抗性及其与花生安全贮藏关系的分析

为探究花生收获前黄曲霉毒素污染抗性及其与花生安全贮藏关系,测定具有收获后产毒抗性花生品系的收获前黄曲霉菌侵染率和毒素含量,分析收获前、后黄曲霉毒素污染抗性与花生安全贮藏的关系。结果表明:不同花生品种(系)在生长期间抵抗黄曲霉菌侵染或产毒能力不同,中花6号和J091收获前黄曲霉菌侵染率较高,但产毒量与其他材料相当,表明其具有一定的收获前产毒抗性。收获前抗性与收获后抗性无相关性,但收获前黄曲霉菌侵染率与贮藏花生的黄曲霉毒素含量显著正相关。因此,控制花生收获前的黄曲霉菌侵染,尤其是通过遗传改良选育兼备收获前、后抗性的花生新品种,是降低黄曲霉毒素污染,保证花生食用安全性的有效措施。

2种水分条件下玉米苗期根系性状QTL分析

利用DH1M×T877衍生的180个玉米RIL家系在正常水分和干旱条件下对苗期主胚根长、种子根长、种子根数、节根夹角、节根直径、节根根长和节根数7个根系性状进行QTL分析。结果表明:2种环境下共检测到51个QTL,正常水分条件下检测到31个QTL,干旱条件下检测到20个QTL,单个QTL可解释4.82%～17.14%的表型变异。干旱条件下,在第2和第3染色体上分别检测到1个控制多个性状的QTL;正常水分条件下,在第1和第7染色体上分别检测到1个控制多个性状的QTL;仅在第7染色体上检测到1个控制2种水分条件下种子根长度的QTL,而其余性状均未发现共同的QTL。

玉米生物育种:现状与展望

玉米是我国重要的粮食、饲料和工业原料兼用作物,也是利用杂种优势最广泛、最成功的作物之一,遗传改良对玉米单产提高起到了关键作用。本文总结了玉米育种基础研究进展、前沿关键技术创新和品种培育等方面的发展趋势以及我国发展现状与存在的问题,并对今后的研究方向和发展重点提出建议。

基于AMMI模型和GGE双标图对江苏省甜玉米区域试验的分析

利用AMMI模型和GGE双标图方法,对2019年江苏省甜玉米品种区域试验的9个参试品种和8个区试点进行了评价分析。结果表明,基因型、环境及基因型与环境互作均对甜玉米产量存在极显著影响。参试甜玉米品种中,‘萃甜617’、‘晶甜13’、‘晶甜14’和‘BMB458’具有较好的高产性,而‘BMB458’、‘晶甜0718’、‘晶甜14’和‘晶甜13’的稳产性较好。参试品种‘晶甜13’、‘晶甜14’和‘BMB458’同时具有较好的高产性和稳产性,且具有较广的区域适应性,是本区域试验中较为理想的品种。而‘萃甜617’在南京市种子管理站、泰兴农科所和江苏徐农种业科技有限公司区试点具有特殊适应性。此外,泰兴农科所和海门农科所区试点具有较强的区分力和较好的代表性,是本区域试验的理想区试点。AMMI模型和GGE双标图两种方法的综合应用充分解析了参试品种和区试点的特性,研究结果将为甜玉米品种选育提供参考。

AMMI模型和GGE双标图在江苏省糯玉米品种区域试验中的应用

基于AMMI模型和GGE双标图对2020年江苏省糯玉米品种区域试验的15个参试品种和7个区试点进行了评价分析。结果表明,基因型效应和环境效应对糯玉米产量存在统计学上的显著影响,并且基因型和环境间存在显著的互作效应。供试的糯玉米品种中,‘晶彩甜糯2号’、‘浙糯208’、‘萃甜糯526’、‘通甜糯898’、‘津鲜糯386’和‘徐彩甜糯029’具有较高的丰产性;而‘苏玉糯908’、‘苏科糯1804’和‘通甜糯898’具有较好的稳产性;‘晶彩甜糯2号’和‘徐彩甜糯029’适宜种植的区试点最多,具有较强的区域适应性。‘通甜糯898’较其他品种具有较高的丰产性和较好的稳产性,更接近理想品种。此外,南京市种子站和南京农业大学江浦基地具有较高的区分力和较好的代表性,是本研究的理想区试点。本研究综合使用AMMI模型和GGE双标图实现了对品种和区试点更全面有效的评估,为糯玉米新品种的选育推广以及区试点的选择提供理论依据。

A new statistical method for mapping QTLs underlying endosperm traits

Genetic expression for an endosperm trait in seeds of cereal crops may be controlled simultaneously by the triploid endosperm genotypes and the diploid maternal genotypes. However, current statistical methods for mapping quantitative trait loci (QTLs) underlying endosperm traits have not been effective in dealing with the putative maternal genetic effects. Combining the quantitative genetic model for diploid maternal traits with triploid endosperm traits, here we propose a new statistical method for mapping QTLs con- trolling endosperm traits with maternal genetic effects. This method applies the data set of both DNA molecular marker genotypes of each plant in segregation population and the quantitative observations of single endosperms in each plant to map QTL. The maximum likelihood method implemented via the expectation-maximization algorithm was used to the estimate parameters of a putative QTL. Since this method involves the maternal effect that may contribute to en- dosperm traits, it might be more congruent with the genetics of endosperm traits and more helpful to increasing the preci- sion of QTL mapping. The simulation results show the pro- posed method provides accurate estimates of the QTL effects and locations with high statistical power.

Framework for dissection of complex cytonuclear epistasis by a two-dimensional genome scan

Epistasis between cytoplasmic and nuclear genes is the primary genetic component of complex quantitative traits.Genetic dissection of cytonuclear epistasis is fundamentally important to understand the genetic architecture of complex traits.In this study,a two-dimensional genome scan strategy was employed to evaluate the contribution of cytoplasm,quantitative trait loci (QTL),QTL×QTL interactions and QTL×QTL×cytoplasm interactions to the phenotypic variation.The p-value and parameter value for each genetic effect were calculated by multiple regression analysis.A stepwise approach was suggested to build confidence in candidate QTL on the basis of q-value estimation,false discovery rate calculation and Bonferroni adjustment.A fine-scale grid scan strategy was proposed for further analysis of peaks of interest.Plant height in maize was used as an example to illustrate the efficiency of the two-dimensional genome scan strategy.

基于高密度遗传图谱的玉米抗倒伏相关性状QTL分析

倒伏是影响玉米高产稳产的重要因素,解析玉米抗倒性遗传机制对选育抗倒玉米新品种具有重要意义。本研究以T877×DH1M重组自交系为试验材料,对7个抗倒伏相关的性状进行表型调查和分析,结合高密度遗传图谱进行QTL定位。主要结果如下:T877和DH1M在茎长、茎秆硬皮穿刺强度、茎秆抗拉弯强度、茎压碎强度、穗位高等性状上存在显著差异,这些性状在RIL群体中存在广泛的遗传变异。本文研究的7个性状均表现出连续变异的特点,基本符合正态分布,属于典型的数量性状。相关分析表明茎杆强度相关性状(茎秆硬皮穿刺强度,茎秆抗拉弯强度和茎秆垂直压碎强度)相互间存在明显的正相关(r=0.430～0.772),并且与茎粗存在显著正相关(r=0.254～0.649)。对株高、穗位高、第三节茎长、茎粗、茎秆硬皮穿刺强度、茎秆抗拉弯强度和茎秆垂直压碎强度7个性状进行QTL定位,共计定位到22个QTL,每个性状能检测到1～6个QTL,单个QTL仅能解释5.04%～10.36%,表明这些性状主要受到多个微效位点的控制。研究结果将为玉米抗倒伏分子育种提供理论依据。

Genetic analysis and gene cloning of a triangular hull 1 (tri1) mutant in rice (Oryza sativa L.)

Grain shape and size are two key factors that determine rice yield and quality. In the present study, a rice triangular hull mutant (tri1) was obtained from the progeny of japonica rice variety Taipei 309 treated with 60Co γ-rays. Compared to the wild type, the tri1 mutant presents a triangular hull, and exhibits an increase in grain thickness and protein content, but with a slight decrease in plant height and grain weight. Genetic analysis indicated that the mutant phenotype was controlled by a recessive nuclear gene which is stably inherited. Using a map-based cloning strategy, we fine-mapped tri1 to a 47-kb region between the molecular markers CHR0122 and CHR0127 on the long arm of chromosome 1, and showed that it co-segregates with the molecular marker CHR0119. According to the rice genome sequence annotation there are six predicated genes within the mapped region. Sequencing analysis of the mutant and the wild type indicated that there was a deletion of an A nucleotide in exon 3 of the OsMADS32 gene, which could result in a downstream frameshift mutation and premature termination of the predicted polypeptide. Both semi-quantitative and real-time RT-PCR analyses showed that this gene expressed highly in young inflorescences, while expressed at very low levels in other tissues. These results implied that the OsMADS32 gene could be a candidate of TRI1. Taken together, the results of this study lay the foundation for further investigation into the molecular mechanisms regulating rice caryopsis development.

Bin-based model construction and analytical strategies for dissecting complex traits with chromosome segment substitution lines

Chromosome segment substitution lines have been created in several experimental models,including many plant and animal species,and are useful tools for the genetic analysis and mapping of complex traits.The traditional t-test is usually applied to identify a quantitative trait locus (QTL) that is contained within a chromosome segment to estimate the QTL's effect.However,current methods cannot uncover the entire genetic structure of complex traits.For example,current methods cannot distinguish between main effects and epistatic effects.In this paper,a linear epistatic model was constructed to dissect complex traits.First,all the long substituted segments were divided into overlapping small bins,and each small bin was considered a unique independent variable.The genetic model for complex traits was then constructed.When considering all the possible main effects and epistatic effects,the dimensions of the linear model can become extremely high.Therefore,variable selection via stepwise regression (Bin-REG) was proposed for the epistatic QTL analysis in the present study.Furthermore,we tested the feasibility of using the LASSO (least absolute shrinkage and selection operator) algorithm to estimate epistatic effects,examined the fully Bayesian SSVS (stochastic search variable selection) approach,tested the empirical Bayes (E-BAYES) method,and evaluated the penalized likelihood (PENAL) method for mapping epistatic QTLs.Simulation studies suggested that all of the above methods,excluding the LASSO and PENAL approaches,performed satisfactorily.The Bin-REG method appears to outperform all other methods in terms of estimating positions and effects.