小麦与山羊草双二倍体抗病性的研究与利用

本文报道了波斯小麦与粗山羊草(5个品系),小伞山羊草和卵穗山羊草双二倍体及其亲本的抗叶锈和白粉病鉴定结果。粗山羊草对叶锈的抗性受波斯小麦品系 PS 5(不抗叶锈)的抑制,在双二倍体中不能表现。小伞山羊草和卵穗山羊草对叶锈的抗性不受波斯小麦的影响,能在双二倍体中充分表达。以对白粉病免疫的波斯小麦为母本与免疫的山羊     

小麦D基因组产量性状QTL定位

粗山羊草是普通小麦的D染色体组供体,为了寻找粗山羊草中对小麦产量性状遗传改良有益的基因,通过对四倍体硬粒小麦与粗山羊草杂交合成的双二倍体Am6-1和普通小麦品种Ph85-16的回交一代进行产量性状变异特点分析,发现粗山羊草的D组染色体对小麦的产量性状具有显著影响,千粒重、穗长、穗粒数和每穗小穗数明显高于Ph85-16;同时利用130对SSR引物对几个与产量性状相关的QTL位点进行了定位,初步寻找到4个主效QTL,它们分别为与穗长相关的QSl．sdau-5D,其贡献率为31．58％,与株高相关的QPh．sdau-1D,其贡献率为25．38％,与穗粒数相关的QGs．sdau-5D,其贡献率为44.65％,与千粒重相关的QTgw．sdau-3D,其贡献率为61．62％。     

粗山羊草抗小麦白粉病基因遗传多样性的研究

粗山羊草(Ae.tauschii(Coss.)Schmal.)是普通小麦(T.aestivum L.)抗性改良的宝贵遗传资源。本研究对来自伊朗、前苏联等8个国家和地区的78份粗山羊草进行了小麦白粉病(powderymildew)混合菌种苗期接种鉴定,表现免疫或近免疫的有45份,占57.69％;用一套白粉病菌菌株(共16个)对原产地不同的11份粗山羊草分别进行苗期接种鉴定,结果表明除Y168表现感染外,其它10份材料表现出各自不同的抗性反应,只有来自伊朗的Y219、Y221、Y225和来自的苏联的Ae37能抗所有16个菌株,而没有感染的毒性菌株,说明它们可能含有新的不同于15个已知Pm基因的抗性基因。利用完全双列杂交对原产地不同的5份粗山羊草进行了苗期抗白粉病基因的遗传分析,出现3种不同的抗性基因类型,来自伊朗的3份材料表现单显性(PmA)或双显性(PmA、PmB)2种类型,而来自前苏联的2份材料表现出不同于前两种类型的另一种单显性(PmB)类型。从而为增加普通小麦抗白粉病基因的遗传多样性奠定了基础。     

山羊草基因组及其在小麦改良中的应用研究进展

山羊草属是小麦近缘植物中与小麦亲缘关系最为密切的属.其中蕴藏着许多抗病、抗虫、抗逆、蛋白含量高等有益基因.在小麦进化中起着重要作用,是小麦改良重要的基因资源.山羊草有益基因向小麦遗传背景的导入,主要利用小麦-山羊草双二倍体为桥梁亲本,通过杂交、回交等方式获得小麦异代换系、异附加系、异易位系;并且利用形态标记、细胞学标记、生化标记及分子标记对小麦遗传背景下的染色体组、染色体、染色体臂及片段进行鉴定.本文对这些方面的研究进展进行了综述,对山羊草可利用基因进行了展望.     

硬粒小麦与偏凸山羊草部分双二倍体的核型研究

通过硬粒小麦（AABB，2n＝28）与偏凸山羊草（DDMvMv，Zn＝28）杂交，今成选育出遗传上相对稳定的部分双二倍体。利用核型分析，初步鉴定出该部分双二倍体具有编凸山羊草的染色体组，从而证实了杂种的真实性。该部分双二倍体的获得为将硬粒小麦，特别是偏凸山羊草的优异基因向小麦转移奠定了基础。     

波斯小麦与山羊草杂种F_1自然形成双二倍体的细胞遗传学研究(摘要)

在小麦与山羊草杂交中发现,波斯小麦品系Pss与粗山羊草、卵穗山羊草、小伞山羊草、顶芒山羊草以及钩刺山羊草的杂种F_1具有可育性,自交产生一批小麦—山羊草双二倍体。对波斯小麦×粗山羊草杂种F_1的细胞学研究表明,可育性是由于杂种F_1以两种途径形成了未减数配子。1.一部分花粉母细胞第一次分裂消失,只发生第二次分裂。     

小麦品系抗小麦白粉病基因分子标记鉴定

利用与3个抗小麦白粉病基因(PmPS5A, PmPS5B, PmY39)连锁的微卫星标记对分别由波斯小麦PS5和（或）小伞山羊草Y39衍生的72个小麦抗病品系进行了抗白粉病基因鉴定。在24个由波斯小麦PS5和小伞山羊草Y39合成的双二倍体Am9衍生的品系中,有2个品系含有PmPS5A的标记,有19个品系含有PmPS5B的标记,有7个品系含有PmY39的标记,还有     

小麦新种质N9628-2抗白粉病基因的SSR分析

以抗白粉病的波斯小麦-小伞山羊草双二倍体Am9为母本, 与高感白粉病的普通小麦品种陕160杂交, 并用陕160回交一次, 从其后代中选育的普通小麦种质N9628-2对陕西省关中地区白粉病流行小种关中4号表现免疫。为了明确N9628-2所携带抗性基因的遗传方式及与抗性基因连锁的分子标记, 对该种质的抗白粉病基因进行了遗传分析和SSR标记分析。用高感白粉病品种陕160、陕优225与N9628-2杂交, F₁代对白粉病均表现高抗, F2代抗感分离比例均符合3∶1, 表明N9628-2的白粉病抗性由1对显性基因控制。通过208对SSR引物对陕160 ´ N9628-2 F2代抗感分离群体的142个单株的检测, 发现位于6A上的SSR位点Xwmc553和Xwmc684在双亲和抗、感池间有特异性, 并与抗性基因连锁, 遗传距离分别是10.99和7.43 cM, 表明抗病基因可能位于6A染色体上。 用中国春部分第6同源群的缺体-四体系和双端体系进行验证, 进一步将抗性基因定位在6AS。用连锁的SSR标记和相关亲本分析表明, 该抗病基因可能来源于小伞山羊草Y39, 它不同于已有抗白粉病基因, 可能是一个新基因。     

两种山羊草携带Gc基因的新发现

由栽培二粒小麦和沙融山羊草形成的双二倍体，再和高大山羊草一起，替换了普通小麦细胞质，形成代换系。这个代换系的后代携带两个新的Ｇｃ基因。Ｃ－带分析表明：一个基因位于高大山羊草５Ｓ染色体或类似５Ｓ的染色体上，而另一个基因，位于沙融山羊草的４Ｓ染色体上。     

27个二倍体和10个四倍体小麦近缘种抗叶锈性鉴定

利用我国小麦叶锈菌5个优势致病类型的混合菌种,在田间对27个二倍体和10个四倍体小麦近缘种成株期抗病性进行了接种鉴定,发现3个粗山羊草、1个野生二粒小麦和3个硬粒小麦表现免疫,1个一粒小麦、9个粗山羊草和1个硬粒小麦表现抗病,说明目前这些材料所含抗叶锈病基因有很高的开发应用价值。选择18个有鉴别作用的小麦叶锈菌致病类型,在不同温度下进行苗期抗叶锈病基因推导,根据抗感反应模式,推定粗山羊草Y192含Lr40,Ae37和Y190含Lr41,硬粒小麦Altar 84、Doliu、Dr147和Volcani 447含Lr23和未知基因;Ae39、T96243和Y193等10个粗山羊草和野生二粒小麦不含苗期抗叶锈病基因。粗山羊草Ae39、T96243、Y193和野生二粒小麦在成株期表现免疫至抗病且严重度≤10%,说明具有成株期抗病性特点。     

Waxy proteins and amylose content in tetraploid wheats Triticum dicoccum Schulb, Triticum durum L. and Triticum polonicum L.

This paper reports the waxy proteins and apparent amylose contents of the tetraploid species Triticum dicoccum, Triticum polonicum and Triticum durum. Three waxy proteins were found in the three species; two showed the same electrophoretic mobility as the alleles Wx-A1a and Wx-B1a of the hexaploid variety ‘Chinese Spring’, while the third showed the same mobility as the allele Wx-B1e belonging to the hexaploid wheat variety ‘Bai Huo’. In apparent amylose content no significant differences between the alleles Wx-B1a and the Wx-B1e were found for each species. However, the mean amylose contents of T. durum and T. polonicum were significantly greater than that of T. dicoccum, regardless of which allele was present. This revised version was published online in July 2006 with corrections to the Cover Date.     

Performance of Selected Strains of 'Farro' (Triticum monococcum L., Triticum dicoccum Schübler, Triticum Spelta L.) and Durum Wheat (Triticum Durum Desf. cv. Trinakria) in the Difficult Flat Environment of Southern Italy

The aim of this study was to evaluate the performance of three species of unhulled-wheat (Triticum monococcum L., Triticum dicoccum Schubler and Triticum spelta L.) with respect to durum wheat (Triticum durum Desf. cv. Trinakria) in southern Italy's flat environment.
As far as yield is concerned, the mean yield was significantly different among species. Durum wheat yielded 16.1 %, 37.6% and 69.5 % more than dicoccum, spelta and monococcum species, respectively.
Among unhulled-wheat species, only Triticum dicoccum showed some similarity with durum wheat, such as one-thousand kernels weight, plant height and number of spikes per m².
Among the factors studied, the days to reach heading represented the factor that mostly influenced yield     

Inheritance of leaf angle in Triticum aestivum L.

Summary A 6×6 diallel was prepared to study the inheritance of leaf angle in T. aestivum L. Genetic analysis in terms of diallel cross parameters and graphic analysis indicated the control of additive gene effects in the expression of this character. The results of F₁ analysis were supported by the analysis of F₂ data.     

Genomic Relationships of Triticum sharonense with Other S-Genome Diploid Triticum Species

Triticum sharonense was hybridized with autotetra-ploid T. speltoides, T. longissimum and T. bicorne. Meiotic analysis of these hybrids showed that T. sharonense is almost equally related to both T. speltoidcs and T. longissimum, while it is comparatively distant from T. bicorne. Therefore, this study does not support treating T. sharonense as a subspeies or variety of T. lottgissimum.     

小麦谷胱甘肽S-转移酶基因的克隆及原核表达

为了进一步研究小麦谷胱甘肽-S-转移酶基因(TaGST)的功能,采用RT-PCR方法分离了小麦谷胱甘肽-S-转移酶基因(TaGST)的ORF全长c DNA,并进行了生物信息学分析。结果表明:小麦TaGST基因的ORF全长690 bp,编码229个氨基酸;TaGST蛋白分子质量为25.81 k Da,p I为5.29。系统进化分析表明,该基因编码蛋白与水稻OsGST蛋白的氨基酸同源性最高,与已知植物GST家族成员的氨基酸序列聚类分析将TaGST聚为Phi类GST。构建原核表达载体p ET32-TaGST,对TaGST基因进行原核表达,SDS-PAGE结果表明,其所表达蛋白与预期蛋白大小一致。为进一步研究该基因的特性和功能奠定了理论基础。     

Culture selected somaclonal variation in five Triticum aestivum L. genotypes

Somaclones (R₃ and R₄ generations) regenerated from five winter wheat (Triticum aestivum L.) genotypes were evaluated for variation in agronomic and morphological characters. Immature embryos were used as initial explant material. Comparisons for plant height, top internode length, spike length, number of seeds per spike and 100 seed weight were made between the somaclones and their parents. Some morphological variations of stem and spike characteristics were registered which demonstrate that plant height and spike length can be changed by using immature embryo culture. The results obtained may be considered a biotechnological contribution to wheat plant improvement. This revised version was published online in August 2006 with corrections to the Cover Date.     

Growth habit in common wheat (Triticum aestivum L. em. Thell.)

Summary A study of the Vrn genotypes of 642 spring wheats supports the theory that only Vrn1, Vrn2 and Vrn3 exist in Tricticum aestivum. In none of the varieties investigated Vrn4 was present. Seven varieties, which according to literature carry Vrn4, showed to carry Vrn1, Vrn2 and/or Vrn3. Some varieties were mixtures of Vrn-genotypes, which could mislead geneticists in pooled data analysis. Other causes for misinterpretation of the data could be hybrid necrosis, hybrid dwarfness or a wrong determination of plants with a winter habitus. Only Hope was dominant on another Vrn locus. Its haploid Vrn-genotype is Vrn1 vrn2vrn3 Vrn5.     

Effects of N fertilization on yield for low-input production in Spanish wheat landraces (Triticum turgidum L. and Triticum monococcum L.)

A core subset of Spanish durum wheat landraces was evaluated at two nitrogen levels (80 and 220 kg/ha) to identify landrace genotypes adapted to low N production. Yield differences were statistically significant between N levels and among genotypes at both levels. Fifty-one per cent of the landraces yielded significantly more at low than at high N (low-N varieties) while 26% had a positive (high-N varieties) and 23% an indifferent (indifferent-N varieties) response to N fertilizer. No significant agromorphological differences were found among low and high-N varieties at low N level that conferred some advantage to low-N varieties. In contrast, high-N varieties possessed longer grain-filling period under high N level. Phenological characters showed an important influence on yield and on the performance of the varieties within each subgroup. The traits affecting grain yield most positively, mainly the low-N varieties, were long filling period and earliness. Five entries were selected for prebreeding to low N adaptation.     

Callus formation and plantlet regeneration from immature Triticum durum Desf. embryos

Summary Experiments upon in vitro culture of immature durum wheat embryos, harvested at different growth stages, were made in two consecutive years. Callus formation and plantlet regeneration were obtained. The ability to form callus and the degree of morphogenetic processes varied with the different hormonal treatments used and with the age of the embryos. In the first year the best response for callus growth was observed with 2,4-D 2 mg l^-1 plus adenine 50 mg l^-1 or 2,4-D 5 mg l^-1 alone in the more mature embryos (15 and 20 days after anthesis). On the contrary, NAA 5 mg l^-1 had a greater shoot regeneration effect. In the next year, at all 2,4-D concentrations and for the two different ages of the embryos tested, all embryos formed callus. Regeneration of plantlets was obtained in higher percentage in calli originated from the more developed embryos. The effect of changed media upon plantlet regeneration was studied after callus transplant.Investigation by cytophotometry and chromosome counts on different calli showed, practically in all cells, a diploid condition. A histological analysis demonstrated embryogenic somatic characteristics in many samples of callus. The pattern of organogenesis seemed to be via adventitious bud formation but structures resembling embryoids were also observed in the callus.