Genetic Analysis of Grain Yield in a 7×7 Diallel Cross F_2 Population of Wheat(T.Aestivum L.)

In order to obtain genetic information for grain yield, seven genetically diverse wheat cultivars were crossed in an incomplete diallel to study the inheritance of grain yield using F_2 progenies for two years. Significant differences were observed among genotype, year and genotype × year interaction for grain yield, and both general combining ability(GCA) and specific combining ability(SCA) were also highly significant for grain yield, suggesting that the trait was controlled by both additive and non-additive effect. The GCA estimates revealed that the best combiners for grain yield were Yangmai 5 and Ningmai 9. Adequacy tests revealed that data of grain yield was fully adequate for genetic interpretation. Over-dominance genetic effects were important for the expression of grain yield. Grain yield exhibited moderately high value of narrow sense heritability(h_N^2=66.98% and h_N^2=72.37%).

Identification of Triticum aestivum-Haynaldia villosa Translocation Line T6BS·6BL-2VS

[Objective] The aim of experiment was to provide a new germplasm for wheat breeding by further using desirable genes in 2V chromosome of Haynaldia villosa.[Method] Through hybridization between common wheat(Triticum aestivum)-Haynaldia villosa disomic substitution line and common wheat Nonglin26-3C chromosome of Aegilops triuncialis disomic addition line,the analysis methods such as chromosome C-banding,genomic in situ hybridization and molecular marker technique were comprehensively applied and combined characters investigation.[Result] The wheat-Haynaldia villosa translocation line(T6BS·6BL-2VS)was selected from hybrid progenies to conduct characters investigation,which found some bristles on glume ridge of T6BS·6BL-2VS.[Conclusion] The translocation line induced by gametocidal chromosome was a small segment translocation line and the gene of bristle on glume ridge of Haynaldia villosa was located between the middle and the terminal of 2VS.

普通小麦(T.aestivum L.)不同作图群体抽穗期QTL分析

【目的】对小麦抽穗期进行数量性状位点(QTL)分析。【方法】以旱选10号/鲁麦14和温麦6号/山红麦两个作图群体为材料,在大田及温室条件下,观察小麦抽穗期等性状。利用混合线性模型,进行QTL分析。【结果】抽穗期在两个作图群体中均呈现连续分布,表现为多基因控制的数量性状;共检测到9个QTL位点,分别位于染色体2D、3B(2个)、3D、4A、5B、6B、6D和7D上,对抽穗期的贡献率在3.97%～22.91%之间;有15组QTL位点之间存在基因互作效应,互作的加性效应大小范围为0.77～2.16 d,互作效应对性状的贡献率在4.35%～21.44%之间。【结论】抽穗期QTL的检测受环境影响较大;抽穗期QTL位点在染色体上的分布较多;不同染色体间则存在基因互作现象。

Wheat breeding in northern China: Achievements and technical advances

Common wheat is the major cereal crop that underpins the food safety of China. Both winter wheat and spring wheat are grown on ~24 million ha. This review aims to summarize the current status of wheat production and breeding progress in the northern wheat production areas of the country, and to review recently advanced technologies being applied in wheat breeding, including the use of dwarf-male-sterile(DMS) wheat, speed breeding and specialized wheat breeding SNP chips. Crossing is the initial step in most breeding programs. DMS wheat is a convenient tool for large scale production of hybrid seed. Speed breeding or accelerated generation turnover attempts to reduce the time taken in cultivar development. Several different SNP chips are high-throughput, genome-wide genotyping platforms for breeding and research.

Distribution of Grain Hardness in Chinese Wheats and Genetic Analysis

A hundred winter wheat and 41 spring wheat cultivars and advanced lines were used to investigate the distribution of grain hardness in Chinese wheats and correlations between grain hardness and other kernel traits. P1, P2, F1 , F2 and F3 from three crosses, i. e. , Liken2/Yumai2, 85Zhong33/Wenmai6 and 85Zhong33/95Zhong459 were sown to study the genetics of grain hardness. Significant correlation was observed between hardness measured by Single Kernel Characteristic System 4100 (SKCS 4100) and Near Infrared (NIR) Spectroscopy, r ranging from 0.85 to 0.94. Chinese wheat is a mixed population in terms of hardness, ranging from very soft to very hard. For autumn-sown wheat, on average, grain hardness decreases from north to south and spring-sown wheat is dominant with hard type. Hardness is negatively associated with flour color, and its associations with flour yield and ash content differ in winter and spring wheats. Grain hardness is controlled by a major gene and several minor genes with additive effect mostly, but dominant effect is also observed, with heritability of 0.78.

Three co-located resistance genes confer resistance to leaf rust and stripe rust in wheat variety Borlaug 100

Leaf rust(LR) and stripe rust(YR) are important diseases in wheat producing areas worldwide and cause severe yield losses under favorable environmental conditions when susceptible varieties are grown. We determined the genetic basis of resistance to LR and YR in variety Borlaug 100 by developing and phenotyping a population of 198 F6 recombinant inbred lines derived from a cross with the susceptible parent Apav#1. LR and YR phenotyping were conducted for 4 and 3 seasons, respectively, at CIMMYT research stations in Mexico under artificial epidemics. Mendelian segregation analyses indicated that 3–5 LR and 2 YR genes conferred resistance in Borlaug 100. Lr46/Yr29(1 BL), Yr17(2 AS) and Yr30(3 BS) were present in the resistant parent and segregated in the RIL population based on characterization by molecular markers linked to these genes. When present alone, Lr46/Yr29 caused average 13% and 16% reductions in LR and YR severities, respectively, in RILs. Similarly, Yr17 and Yr30 reduced YR severities by 57% and 11%, respectively. The Yr30 and the Yr17 translocation were also associated with 27% and 14% reductions, respectively, in LR severity, indicating that the 3 BS and 2 AS chromosomal regions likely carry new slow rusting LR resistance genes, temporarily designated as Lr B1 and Lr B2, respectively. Additive effects of Yr30*Yr17, Yr29*Yr17 and Yr29*Yr30 on YR and LR were significant and reduced YR severities by 56%,55%, and 45%, respectively, and LR severities by 34%, 40%, and 45%, respectively. Furthermore, interaction between the three genes was also significant, with mean reductions of 70% for YR and 54% for LR severities. Borlaug 100, or any one of the 21 lines with variable agronomic traits but carrying all three colocated resistance loci, can be used as resistance sources in wheat breeding programs.

The wheat receptor-like cytoplasmic kinase TaRLCK1B is required for host immune response to the necrotrophic pathogen Rhizoctonia cerealis

Receptor-like cytoplasmic kinases(RLCKs)represent a large family of proteins in plants.In Arabidopsis and rice,several RLCKs in subfamily VII(RLCKs-VII)have been implicated in pathogen-associated molecular pattern-triggered immunity and basal resistance against bacterial and fungal pathogens.However,little is known about roles of RLCKs-VII of the important crop common wheat(Triticum aestivum)in immune responses.Here,we isolated a RLCK-VII-encoding gene from wheat,designated as TaRLCK1B,and investigated its role in host immune response to infection of a necrotrophic fungus Rhizoctonia cerealis that is a major pathogen of sharp eyespot,a destructive disease of wheat.RNA-sequencing and RT-qPCR analyses showed that transcriptional level of TaRLCK1B was significantly higher in sharp eyespot-resistant wheat cultivars than in susceptible wheat cultivars.The gene transcription was rapidly and markedly elevated in the resistant wheat cultivars by R.cerealis infection.The TaRLCK1B protein was closely related to OsRLCK176,a rice resistance-related RLCKs-VII,with 84.03%identity.Virus-induced gene silencing plus wheat response to R.cerealis assay results indicated that silencing of TaRLCK1 impaired resistance to R.cerealis.Meantime,silencing of TaRLCK1 significantly elevated both the content of H2 O2(a major kind of reactive oxygen species,ROS)and the transcriptional level of the ROS-generating enzyme-encoding gene RBOH,but repressed the expression of the ROS-scavenging enzyme-encoding gene CAT1 at 18 hours after inoculation(hai)with R.cerealis.Taken together,these data suggested that TaRLCK1B was required for the early immune response of wheat to R.cerealis through modulating ROS signaling in wheat.

Investigation on Paste Property of Chinese Bread Wheat Varieties

Starch viscosity is closely associated with noodle quality. RVA(rapid viscosity analyzer) was used to investigate the paste property of leading Chinese wheat varieties arid 38 Australian wheat lines. Results showed that significant variability for RVA parameters was observed among Chinese wheat varieties, particularly among spring wheat varieties. In general, Australia wheat lines performed better paste characters than that of Chinese winter wheats. Genotype (G), environment (E) and genotype by environment (G×E) interaction affected all paste traits. Correlation analysis indicated that peak viscosity correlated highly and significantly with viscosity, breakdown, setback, final viscosity, peak time, and falling number(r = 0.56-0.93, P<0.01). However breakdown was not significantly associated with most paste properties. Paste characters increased from low to high latitude both in the north and south part of Yellow and Huai Valley.

The Application of Somaclonal Variation in Early Maturity,High Yield and High Quality Improvement in Wheat

Yield characters, maturity and grain protein content of somaclones derived both from immature embryo of cultivar 77(2)-Spring and single-cell culture of cultivar NE7742 in vitro were studied and the wide variation was found. Somaclones with maturity 8 days earlier than or the same as CK NE 7742 (high yield, early maturity and high quality), combining with high quality (grain protein content 15.5% - 18%) and high yield (the same as 7724 or higher) have been found and selected and now multiplied for 8 generations. The results of cultivar comparison trial in 1995 showed that several somaclones (the yields were significantly higher than CK DN120) could be used directly in wheat production. The studies confirmed that somaclonal variation is one of the effective ways for early maturity, high-yielding and high-quality improvement in wheat.

外源茉莉酸甲酯对BNS366雄性育性的影响

为探究外源茉莉酸甲酯(methyl jasmonate,MeJA)对小麦温敏雄性不育系BNS366雄性育性的影响,以BNS366及其近等基因系郑麦366为试验材料,在正常秋季播种(2020年10月12日)和晚播(2020年12月2日)条件下,分别于2021年3月22日和3月31日开始至开花期前,设置0(清水,对照)、50、100、200、300、400和500μmol·L^(-1) MeJA(水溶液,喷施)7个处理,比较分析了不同处理间花粉可育率和自交结实率的差异。结果表明:在正常秋季播种条件下,郑麦366花粉可育率、国内法自交结实率和国际法自交结实率分别为86.31%、70.36%和112.22%,在晚播条件下分别为82.53%、92.53%和166.18%,均正常可育;在正常秋季播种条件下,200μmol·L^(-1) MeJA处理的国际法自交结实率为70.15%,比对照显著降低了42.07个百分点;在晚播条件下,200、300和500μmol·L^(-1) MeJA处理的国内法自交结实率分别为74.71%、74.01%和73.45%,比对照显著降低了17.82、18.52和19.08个百分点;在两个播期下,郑麦366其他浓度MeJA处理的上述3个指标与对照差异均不显著。在正常秋季播种条件下,BNS366花粉可育率为零,达到全不育水平,国内法自交结实率和国际法自交结实率均为0.24%,100μmol·L^(-1) MeJA处理的花粉可育率为88.25%,达到正常可育水平,国内法自交结实率和国际法自交结实率分别为56.41%和94.01%,能正常结实,与对照差异达到显著水平;在晚播条件下,BNS366的上述3个指标分别为51.72%、41.23%和93.08%,正常可育,100μmol·L^(-1) MeJA处理的国际法自交结实率为39.72%,比对照显著降低了53.36个百分点;在两个播期下,BNS366其他浓度MeJA处理的上述3个指标与对照差异均不显著。由此说明,在2020-2021年,外源MeJA对郑麦366和BNS366可育植株的雄性育性可能具有降低效应,对BNS366不育植株的雄性不育性具有较强恢复效应。

小麦籽粒硬度及其Pinb-D1基因等位变异的STS标记检测

为了明确内蒙古春小麦和部分引进冬小麦的籽粒硬度及其等住变异类型，用SKCS 4100单籽粒谷物硬度仪和STS分子标记对17份冬小麦、87份春小麦品种和38份春小麦高代品系的籽粒硬度及其Pinb-D1a、Pinb-D1b和Pinb-D1c等位基因进行了分析。结果表明，在104份冬、春小麦品种中，籽粒硬度指数变幅为1±16-74±21，其中软质、混合和硬质麦频率分别为23．1％、49．0%和27．9％；Pina—D1a／Pinb-D1a、Pina—D1a／Pinb-D1b和Pina—D1a／Pinb-D1c基因型分别为68份、27份和4份。在38份高代品系中，籽粒硬度指数变幅为0±18～49±17，软质和混合麦频率分剐为68．4％和31．6％，Pina—D1a／Pinb-D1a和Pina—D1a／Pinb-D1b基因型分别为20份和18份。

用STS标记检测矮秆基因Rht-B1b和Rht-D1b在中国小麦中的分布

目的明确矮秆基因在中国小麦中的分布,有助于改良小麦株高和提高产量潜力。方法选用中国主要麦区品种(系)239份,用STS标记检测矮秆基因Rht-B1b(Rht1)和Rht-D1b(Rht2)的分布规律,验证其PCR标记在分子标记辅助育种中的可用性。结果(1)Rht-B1b和Rht-D1b特异性STS标记可以准确检测小麦品种的Rht-B1b和Rht-D1b矮秆基因。(2)Rht-B1b基因在全国的平均分布频率为24.3%,新疆冬春麦区高达62.5%,长江中下游冬麦区为42.3%,黄淮冬麦区、北部冬麦区和西北春麦区分别为28%、25.8%和25%,北部春麦区和西南冬麦区分别为9.1%和8.3%,东北春麦区供试材料未携带Rht-B1b基因。(3)Rht-D1b基因在全国的平均分布频率为46.9%,北部春麦区和黄淮冬麦区分别为72.7%和69%,西南冬麦区、西北春麦区和北部冬麦区分别为38.9%、37.5%和35.5%,长江中下游冬麦区和新疆冬春麦区分别为23.1%和12.5%,东北春麦区供试材料未携带Rht-D1b基因。结论分子检测结果和系谱分析表明,中国小麦品种(系)携带的Rht-B1b矮秆基因来自St2422/464和农林10,Rht-D1b矮秆基因来自农林10号、水源86、辉县红和蚰包麦。

普通小麦多酚氧化酶活性的QTL分析

多酚氧化酶 (polyphenoloxidase ,PPO)是引起面团 (片 )颜色褐变的主要原因。利用 12 2对SSR引物、4对贮藏蛋白STS引物和 10对AFLP引物组合 ,分析了中优 95 0 7×CA96 32的 71个DH系的基因型 ,构建了由 173个位点组成的遗传连锁图 ,在小麦 2 1个连锁群上覆盖 2 881cM。将该群体种植于 3个环境 ,采用复合区间作图法 (CIM)进行了PPO活性的QTL分析。结果表明 ,控制籽粒PPO活性的主效QTL有 2个 ,分别位于染色体 2AL和 2DL上 ,贡献率分别为 37 9%～5 0 0 %和 2 5 0 %～ 2 9 1%。所有QTL都来自高PPO活性亲本中优 95 0 7。讨论了通过遗传途径降低PPO活性及利用分子标记辅助育种的可能性。

小麦T、K、V型胞质不育系和杂种mtDNA的RAPD分析及育性相关片段的克隆

用 RAPD技术对细胞质分别来源于粘果山羊草 (Ae.kotschyi)、偏凸山羊草 (Ae.ventricosa)、提莫菲维小麦 (T.timopheevii)的三种普通小麦雄性不育系 - - K型、 V型、 T型及相应的保持系、恢复系以及杂种 F1代的线粒体 DNA(mt DNA)进行了比较分析。结果如下 :(1)发现在 mt DNA组织结构上 K型、V型、T型不育系之间以及与保持系之间均呈现差异 ,这从 DNA水平上提供了三类不育系胞质来源不同的证据 ;(2 )利用 2 3个引物的扩增结果进行了聚类分析 ,绘制出了 T型、K型、V型三种不育系、保持系和 K、V型共同的恢复系及杂种 F1代树式遗传关系图 ;(3)对两个特异的多态性DNA片段进行了回收 ,克隆、并制备探针 ,Southern杂交结果显示不育系与保持系间存在多态性 ,有两个片段可能与育性有一定的联系。

小麦重要品质性状的QTL定位

【目的】发掘重要性状的QTL及其分子标记进行小麦品质分子改良。【方法】采用PH82-2/内乡188杂交后代240个F5:6家系,按照Latinizedα-lattice设计,2004～2005年度分别种植在河南焦作、安阳和山东泰安。对籽粒蛋白质含量、Zeleny沉降值、和面时间、8分钟带宽、峰值粘度和稀懈值进行测定,利用188个SSR标记和4个蛋白标记构建遗传连锁图谱,采用复合区间作图法(CIM)对上述6个品质性状进行QTL定位。【结果】籽粒蛋白质含量检测出3个QTL,分布在3A、3B染色体上。在1B、1D和3B染色体上检测到3个控制Zeleny沉降值的QTL,其中位于1B和1D染色体上的QTL在3个地点均检测到,可解释5.5%～17.6%表型变异。发现3个控制和面时间的QTL,分布在1B和1D染色体上,在3个地点均能检测到,贡献率为7.9%～55.3%;检测出8分钟带宽的QTL5个,其中1B和1D染色体上的QTL在3种环境下均能检测到,贡献率为11.7%～33.9%。发现峰值粘度QTL4个,分布在1A、1B、3A和7B染色体上;检测出稀懈值QTL5个,位于1B、4A、5B、6B和7A染色体上。1B染色体上存在同时控制Zeleny沉降值、和面时间、8分钟带宽、峰值粘度和稀懈值的QTL,与最近标记Glu-B3j连锁距离为0.1～0.8cM,说明1BL/1RS易位对这些性状有重要影响;1D染色体上存在同时控制Zeleny沉降值、和面时间和8分钟带宽的QTL,与最近的标记Dx5+Dy10连锁距离为2.5～3.3cM,表明Dx5+Dy10高分子量谷蛋白亚基对这3个性状影响很大。和面时间和8分钟带宽位于1B和1D染色体的QTL以及稀懈值位于1B染色体上的QTL在3个地点均能检测到,具有环境稳定性。【结论】本研究定位的品质性状的标记可作为小麦品质分子育种的工具。

1BL/1RS易位对小麦产量性状和白粉病抗性的影响及其QTL分析

用PH82-2／内乡188杂交后代240个R5：6家系，按照α-lattice设计，分别种植在安阳、焦作和泰安，对产量和抗白粉病等性状进行了考察。利用SSR和蛋白标记对群体进行部分连锁作图，分析1BL／1RS易位对产量及其相关性状的遗传效应。结果表明，1BL／1RS易位系对产量、穗数／m^2和抽穗期的影响不显著；易位系的千粒重和白粉病抗性显著高于非易位系，但株高和穗粒数减少。利用复合区间作图法进行QTL分析，发现1RS携带1个降低株高的微效QTL，位于HVM20～Sec—1标记区间，可解释4．28％的表型变异；1Rs和1BL携带抗白粉病QTL，分别位于HVM20～Sec—1和Xgwm24～Xwmc320标记区间，解释4．81％和4．66％的表型变异。鉴于1BL／1RS易位对产量的正向作用不明显，其主效抗性已丧失。又对加工品质有明显的负向影响，在小麦品质育种上最好不予应用。

不同生态环境下冬小麦籽粒大小相关性状的QTL分析

【目的】鉴定影响籽粒大小相关性状的QTL,并估计QTL的表型效应;分析不同环境下QTL的稳定性。【方法】以冬小麦小粒地方品种和尚麦为母本,大粒育成品种豫8679为父本及其F7:8重组自交系的142个株系为试验材料,分析籽粒长度、宽度、厚度、体积及千粒重在北京(2006、2007)、合肥(2007)和成都(2007)4个不同环境下的性状表现,并利用已构建的含有170个SSR标记和2个EST标记的遗传图谱,对这5个性状进行QTL定位分析。【结果】4个环境下共检测到93个影响籽粒长度、宽度、厚度、体积及千粒重的QTL,这些QTL分布在除1D和6A之外的所有小麦染色体上。在检测到的QTL中,与籽粒长度、宽度、厚度、体积和千粒重相关的QTL分别为17、16、18、21和21个。另外,本研究还在1A、1B、2A、2D、3A、3B、5A、5B、5D、6A、6D、7B和7D染色体上共发现了18个QTL富集区。【结论】获得93个影响小麦籽粒大小相关性状的QTL,这些QTL可作为利用分子标记辅助育种途径进行小麦遗传改良的依据。

中国和CIMMYT小麦品种Bx7亚基超量表达基因(Bx7^OE)的分子检测

高分子量谷蛋白亚基Bx7的超量表达对提高小麦面筋强度有重要作用。利用反相高效液相色谱(RP-HPLC)和STS标记检测了163份中国和CIMMYT小麦品种(系)的高分子谷蛋白亚基Bx7超量表达基因(Bx7OE)。结果表明,TaBAC1215C06-F517/R964标记和TaBAC1215C06-F24671/R25515标记可分别在含有Bx7OE基因的材料中扩增出447bp和844bp的特异带,在不含Bx7OE基因的材料中无相应目标带,两个STS标记的检测结果完全一致。在163份小麦品种(系)中,11份品种(系)含有Bx7OE基因,占总数的6.7%。RP-HPLC与STS标记检测结果一致。利用这两个STS标记可以方便、快速、准确地检测Bx7OE基因。

普通小麦籽粒黄色素含量的QTL分析

小麦面粉黄色度b^＊值是反映面粉颜色的重要指标，主要与籽粒黄色素含量有关。利用122对SSR引物、4对贮藏蛋白STS引物和10对AFLP引物组合，分析了中优9507×CA9632的71个DH系，构建了由173个位点组成的遗传连锁图，在小麦21个连锁群上覆盖2881cM。将该群体种植2年共计5个地点，测定籽粒黄色素和面粉黄色度b^＊值含量。采用复合区间作图法（CIM）进行了籽粒黄色素含量和面粉黄色度QTL分析。结果表明，面粉黄色度b^＊值的QTL位于染色体1DS、2DL、3A、4D、5D、6AL、6D和7AL上，其中7AL的QTL效应最大，贡献率为12．9％～37．6％；籽粒黄色素含量的QTL位于染色体2DL、3DL、4A、5A和7AL，其中7AL的QTL效应最大，贡献率为12．1％～33．9％。面粉黄色度b^＊值与籽粒黄色素含量共同的QTL位于7AL，与Xgwm264b紧密连锁，遗传距离分别为0～3．9cM和0～0．9cM。

小麦TaFer-A1基因抗旱相关分子标记的开发

铁结合蛋白(Ferritin,Fer)参与干旱胁迫应答反应,开发Fer基因抗旱相关的分子标记可为抗旱小麦品种选育提供依据。本研究依据2个强抗旱性和2个弱抗旱性小麦品种1A染色体上铁结合蛋白基因(TaFer-A1)序列的差异,开发TaFer-A1基因抗旱相关的分子标记,用150份萌发期抗旱性不同的小麦品种(系)对标记的有效性进行验证。克隆序列比对发现,TaFer-A1基因在4份抗旱性极端品种间仅存在7个变异位点,包括6个SNP位点和1个3bp碱基Del/Ins位点,其中仅在基因第1个内含子区域的3个连续碱基TCT的Del/Ins位点变异与4份品种抗旱性的表型相对应,而其余6个SNP位点在强与弱抗旱性品种之间随机发生。根据两组抗旱性极端品种间TCT碱基的差异,设计1对引物开发出了分子标记FerA1i-ntr1。该分子标记在2个强抗旱性品种中扩增出了167bp特异性条带,定名为TaFer-A1a等位变异;在2个弱抗旱性品种中扩增出了170bp特异性条带,定名为TaFer-A1b等位变异,表明FerA1i-ntr1为共显性标记。在分子标记FerA1i-ntr1检测的150份小麦品种(系)中,有73份被检测为TaFer-A1a等位变异类型,平均相对发芽率为70.1%;77份被检测为TaFer-A1b等位变异类型,平均相对发芽率为55.1%。TaFer-A1a等位变异类型品种(系)的平均相对发芽率极显著高于TaFer-A1b等位变异类型的(P<0.01),说明该共显性标记FerA1-intr1可用于小麦抗旱性的鉴定和筛选,也表明TaFer-A1基因与小麦抗旱性有关。