陕西省地方小麦品种黄色素含量基因的遗传分析

面粉及其制成品的色泽是衡量小麦品质的重要指标之一.八氢番茄红素合成酶(Phytoene synthase,Psy)基因是影响小麦黄色素含量的关键基因,利用分子标记检测 98 份陕西省地方小麦品种(系)Psy-A1与 Psy-B1基因的等位变异及其分布,进一步验证Psy-A1与Psy-B1基因分子标记的有效性.利用黄色素含量基因(Psy-A1、Psy-B1) 的功能标记 YP7A 和 YP7B 检测了 98 份陕西省1980年以来自育和引进的小麦品种(系)Psy-A1等位基因Psy-A1a (片段长度为 194 bp,高黄色素含量)、Psy-A1b(片段长度为231 bp,低黄色素含量)和Psy-B1等位基因Psy-B1a (片段长度为151 bp,中黄色素含量)、Psy-B1b (片段长度为156 bp,低黄色素含量)、Psy-B1c (片段长度为428 bp,高黄色素含量) 与 Psy-B1d (片段长度为884 bp,不确定与黄色素含量的关系)的分布情况,并探讨了Psy-A1、Psy-B1等位基因在品种间的遗传关系.结果表明,陕西省主栽小麦品种(系)中Psy-A1a和Psy-A1b 基因型的频率分别为39.8%和60.2%,以低黄色素含量的Psy-A1b基因型为主;Psy-B1a、Psy-B1b、Psy-B1c与Psy-B1d 四种基因型的分布频率分别是24.5%,67.4%,7.1%和1.0%.对属于黄淮冬麦区之陕西汾渭河谷副区的小麦品种(系)Psy-A1a、Psy-A1b、Psy-B1a、Psy-B1b、Psy-B1c和Psy-B1d 基因型的分布频率分别为45.7%、54.3%,17.4%,71.7%,10.9%和0%;对属于西南冬麦区之陕南鄂西丘陵副区的小麦品种(系)Psy-A1a、Psy-A1b、Psy-B1a、Psy-B1b、Psy-B1c和Psy-B1d 基因型的分布频率则分别为32.7%,67.3%,30.8%,63.5%,3.9%和1.9%,说明不同副麦区的小麦品种(系)基因型差异明显,同时可以直接利用黄色素含量基因(Psy-A1和Psy-B1 )的功能标记YP7A和YP7B来提高小麦育种效率.     

硬粒小麦品种Lpx-B1位点等位变异的分子鉴定及其脂肪氧化酶活性

硬粒小麦籽粒中脂肪氧化酶(LOX)与硬粒小麦面制品的加工品质关系密切相关, 而Lpx-B1位点不同变异类型对LOX活性有重要影响。对来自不同国家和地区的167份硬粒小麦品种的LOX活性进行测定, 并对其Lpx-B1位点不同变异类型进行分子鉴定。不同品种间LOX活性差异明显, 变幅为0.20～7.98 AU min^-1 g^-1。在Lpx-B1.1位点鉴定出3种等位变异, 分别为Lpx-B1.1a、Lpx-B1.1b和Lpx-B1.1c, 以Lpx-B1.1a所占比例最高(55.1%), 其次为Lpx-B1.1c (37.1%), 而Lpx-B1.1b仅占7.8%; Lpx-B1.2和Lpx-B1.3二者总是互补出现在不同的品种中, 146份品种为Lpx-B1.2型, 其余21份品种均为Lpx-B1.3型, 表明二者可能互为一对等位因子。在Lpx-B1.1位点的3种等位变异类型中, Lpx-B1.1b类型品种的LOX活性显著高于Lpx-B1.1a和Lpx-B1.1c类型品种, 而Lpx-B1.1c类型品种的LOX活性最低。Lpx-B1.3类型品种的LOX活性显著高于Lpx-B1.2类型的品种。参试品种共有6种Lpx-B1基因型组合, 其中Lpx-B1.1b/Lpx-B1.3基因型的LOX活性显著高于其他基因型, 而Lpx-B1.1c/Lpx-B1.2和Lpx-B1.1c/Lpx-B1.3基因型的LOX活性最低。这些观测结果为硬粒小麦品质育种提供了重要信息。     

硬粒小麦品种资源特征特性鉴定初报

介绍1989～1990年对1278份硬粒小麦材料的株高、熟期、千粒重、冬春性、籽粒、抗病性的观察结果和部分材料的杂交利用情况。     

春性硬粒小麦品种农艺性状的聚类分析

用聚类分析方法,依据成熟期、株高、穗长、穗粒数、千粒重、单穗产量等６个农艺性状,将１２０个春性硬粒小麦品种分为５个类群。     

硬粒小麦染色体的FISH核型分析

采用FISH(荧光原位杂交)技术,分析硬粒小麦(Sauwne 20)染色体的FISH核型特点,为该种质在小麦新品种选育上的应用提供参考。结果表明,Sauwne 20包括14对染色体,Oligo-pTa 535-2红色探针信号主要分布在A组染色体上,而B组染色体上主要分布着明亮丰富Oligo-pSc 119.2-1绿色探针信号;根据这2种探针在Sauwne 20染色体上的分布特点,可以将其不同染色体进行准确地一一鉴别。Sauwne 20与中国春普通小麦的A组和B组染色体的FISH核型基本相似,但又有一定的差别,不同小麦材料间DNA重复序列表现出遗传多样性。     

陕西省地方小麦品种多酚氧化酶基因等位变异检测及分布

小麦籽粒中多酚氧化酶(polyphenol oxidase,PPO)基因活性与面条等面制品颜色褐变密切相关,降低籽粒PPO活性是小麦品质改良的重要目标.利用PPO基因的功能标记PPO18和PPO29,对115份陕西省地方冬小麦品种(系)进行2A和2D染色体上PPO等位基因印Ppo-A 1a、Ppo-A1b和Ppo-D1b检测,并分析了品种等位变异的分布特点.结果显示:PPO18在等位基因Ppo-A1a(高PPO)和Ppo-A1b(低PPO)中分别扩增685 bp和876 bp的片段,PP029在Ppo-D1b(高PPO)等位基因中扩增490bp的片段.115份品种(系)中Ppo-A1a、Ppo-A1b6和Ppo-D1b等位基因的频率分别为37.39%、60.00%和45.22%.在陕西省所培育和引进的冬小麦品种(系)中,地方当家品种中最低PPO活性基因分布较多,而引进的冬小麦品种中高PPO活性基因分布较多.     

A rapid, seedling-based bioassay for identifying low cadmium-accumulating individuals of Durum wheat (Triticum turgidum L.).

We have developed a seedling-based bioassay that iscapable of identifying low Cd-accumulating phenotypes(homozygous and heterozygous) after 96–120 h ofexposure. Our experiments were conducted using¹⁰⁹Cd as a tracer at subtoxic concentrations tosimulate conditions that might be experienced in thefield. Supply of Cd (10^-11 M) to 4-d oldseedlings for 0–8 h resulted in no differences in rootand leaf Cd content between the low (TL05) and high(TL04) Cd-accumulating isolines. Increasing time ofexposure produced significant differences in leaf Cdaccumulation between isolines, with differencesbecoming most pronounced after the bulk of appliedcadmium ( 95%) was depleted from absorption solutions( 72 h). Similar results were obtained with8-d old seedlings, where differences between genotypeswere more pronounced in young leaves (2nd leaf) orshoot bases. Individuals from five low and highCd-accumulating near isogenic pairs (50individuals/isoline) were screened using Cdconcentration of shoot bases as the screeningcriterion. Mean scores within each isoline pair weresignificantly different, although overlap ofindividual scores was observed at intermediate foliarCd concentrations. The 2^nd leaf to root Cdcontent ratio, which reflects root to shoottranslocation, provided a better parameter todistinguish low from high Cd-accumulating isolines. Plants used for this bioassay could also be rescuedfor subsequent experimental crosses, providing a rapidand cost-effective tool for early detection of the lowCd-accumulating phenotype.     

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2 881 cM。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0~3.9 cM和0~0.9 cM。     

小麦抗白粉病基因聚合体DH材料的分子标记鉴定

小麦白粉病是由Blumeria graminis f.sp. tritici引起的世界性病害,利用分子标记辅助选择进行抗白粉病基因累加,可延长品种抗病性寿命,有利于提高育种效率。本研究利用Pm4b的STS-PCR标记,Pm13和PmV的SCAR-PCR标记,以及与Pm12共分离的同功酶标记（α-Amy-1）对来自小麦与玉米杂交产生的双单倍体材料的7个株系和9个穗系的4     

小麦4B染色体上LOX基因的等位变异及其区域分布

为了解中国不同麦区小麦种质资源籽粒脂肪氧化酶（lipoxygenase,LOX）活性相关基因TaLox-B1的差异和分布,利用小麦4B染色体上的功能标记LOX16和LOX18对7个麦区的436份种质资源进行分子检测。结果表明：在供试材料中共检测到3种TaLox-B1基因等位变异类型,分别为TaLox-B1a（与高LOX活性相关)、TaLox-B1b（与低LOX活性相关）和杂合型,其频率分别为19.0％、70.4％和10.6％。小麦LOX活性基因不同变异类型在各生态区的分布存在明显差异：基因型TaLox-B1a在黄淮冬麦区、北部冬麦区和长江中下游冬麦区分布较多,其比例分别为21.1%、19.8%和17.6%;基因型TaLox-B1b在西南冬麦区和长江中下游冬麦区分布较多,比例分别为87.9%、72.5%;杂合型仅存在于北部冬麦区、黄淮冬麦区与长江中下游冬麦区,比例分别为14.2%、12.4%和9.8%。利用标记LOX16和LOX18对53个自选高代品系进行分子检测,发现自选品系仅有TaLox-B1b与杂合型两种基因型,其中基因型TaLox-B1ab有32个,比例为60.4%。采用分子标记辅助选择,有利于快速鉴定小麦籽粒LOX活性,加速LOX的遗传改良和新品种选育。     

圆锥小麦四排穗性状基因的遗传及分子标记分析

四排穗(four-rowed spike, FRS)性状是超数小穗(supernumerary spikelets, SS)性状的一种类型,表现为在一个穗轴节片上近垂直地着生2个无柄小穗,从而增加了小穗数和穗粒数,对提高产量有一定的潜力。为了解圆锥小麦0880 FRS性状的遗传特征,将0880与正常穗(normal spike, NS)圆锥小麦0879杂交,构建了遗传群体,并对0880 (FRS) × 0879 (NS)与0879 (NS) × 0880 (FRS) F₁、F₂及F_2:3植株的穗部性状进行了调查。结果显示,正反交组合的F₁植株均表现为正常穗,F₂群体中正常穗与四排穗符合3∶1的分离比例,表明0880的四排穗性状由隐性单基因控制,将该基因定名为frs1;细胞质对frs1无显著影响。采用已定位于普通小麦A组与B组的SSR分子标记并结合混合分组分析法(BSA), 筛选出32个在双亲及F₂单株构建的四排穗型池和正常穗型池都具有多态性的SSR分子标记,利用JoinMap4.0软件构建了与frs1连锁的2A染色体11个SSR分子标记遗传图谱,其中SSR标记Xwmc598和Xwmc522位于frs1基因两侧,与该基因的遗传距离分别为4.0 cM和2.4 cM。利用2A染色体缺失系对这11个SSR进行物理定位,Xwmc598和Xwmc522均被定位在2A染色体短臂FL0.00~0.78区域。本研究的结果为frs1基因的精细定位及分子标记辅助选择奠定了基础。     

Phosphorus Response Studies on Some Varieties of Durum Wheat (Triticum durum Desf.) and Tef (Eragrostis tef (Zucc.) Trotter) Grown in Sand Culture

The response of four varieties each of durum wheat (DZ-04-118, DZ-320, DZ-918 and TOB-2) and tef (DZ-01-354, DZ-01-787, DZ-01-1445, and DZ-Cr-37) to P application levels was examined in a sand culture study conducted in a glasshouse for 4 weeks. Results showed that plant height, shoot and root dry weights, and plant P uptake were increased by increasing levels of P application from 0 to 5 (tef) and 0 to 10 mg P 100 g⁻¹ (wheat). Varietal differences were also observed in all parameters, except in shoot dry weight of the four durum wheat varieties. In general, all modern varieties of the two crops showed better growth and P uptake than the corresponding traditional varieties. The short period study proved that variations generally existed in the P responses of durum wheat and tef varieties which may be confirmed by long-term study up to maturity. Inclusion of more populations in similar studies may help to identify P efficient genotypes.     

Estimation of outcrossing rate in landraces of tetraploid wheat (Triticum turgidum L.)

A study was undertaken to assess the amount of natural outbreeding in tetraploid wheat landraces of Ethiopian origin. The study consisted of two trials which were planted separately at two locations representing different environmental conditions for two consecutive seasons. The design employed was the randomized complete block with three replications. Two polymorphic loci, glume pubescence and awn condition were utilized as markers. The rate of outcrossing was based on the number of hybrids found in the recessive class of each marker. The overall level of outcrossing was higher in the pure stand trial than in the mixed stand trial. A higher rate of outcrossing occurred in the higher altitude area in the pure stand trial while the opposite was the case in the mixed stand trial. The average rate of outcrossing due to the marker loci was also different, with the long awn displaying more outbreeding tendency. Both locational and seasonal differences in the amount of outcrossing were observed. Generally, the study has revealed that there is a considerable amount of outbreeding in the landraces and that this genetic factor could play a role in preserving variation in the landrace populations. The level of outcrossing detected in this study could have a bearing on the maintenance of the genetic purity of diverse breeding lines being handled together in a breeding nursery and varietal purity in seed multiplication.     

普通小麦D染色体组微卫星分子标记遗传差异研究

本研究采用微卫星(SSR)分子标记技术, 对我国不同生态区的6个春小麦品种(系)及北方冬麦区的17个冬小麦品种(系)D染色体组的遗传多样性进行了分析. 结果显示, 23个微卫星引物在23份材料间共扩增出65个等位基因, 平均每个引物为2.9个. 分析发现, 冬小麦群体内检测到的等位基因数(60个)及平均遗传距离(0.4504)明显高于春小麦(48     

四川小麦品种淀粉特性、多酚氧化酶活性和黄色素含量相关基因的分子标记鉴定

优良面条小麦品种的重要品质特征包括较低的直链淀粉含量、低多酚氧化酶(polyphenol oxidase,PPO)活性和低黄色素含量。本研究利用3个Waxy蛋白、4个PPO活性和6个黄色素含量等位基因的分子标记,对2000-2012年期间四川省审定的105份小麦品种进行基因检测。结果表明:针对淀粉特性,含Wx-B1b基因(Wx-B1缺失)的品种有34份(32.4%),未检测到含Wx-A1b(Wx-A1缺失)和Wx-D1b(Wx-D1缺失)的品种;针对PPO活性,在Ppo-A1位点含Ppo-A1b(低PPO活性)的品种有55份(52.4%),在Ppo-D1位点含Ppo-D1a(低PPO活性)的品种有78份(74.3%);针对黄色素含量,在Psy-A1位点含Psy-A1b(低黄色素含量)的品种有56份(53.3%),未检测到含Psy-A1c的品种,在Psy-B1位点含Psy-B1b(低黄色素含量)的品种有59份(56.2%),未检测到含Psy-B1e的品种。105份品种中兼有Waxy蛋白亚基缺失(Wx-B1b)、低PPO活性(Ppo-A1b和Ppo-D1a)和低黄色素含量等位基因(Psy-A1b和Psy-B1b)的品种有10份,频率为9.5%。利用这些优质基因较全面的品种作为亲本材料,在品质育种中逐步导入上述优质基因,是综合提高四川小麦面条质量的有效途径。