太谷核不育小麦籽粒标记蓝色性状的初步研究

利用太谷核不育小麦和4D-4E 二体代换系杂交,通过中国春 phlb 突变体诱导部分同源配对,试图给太谷核不育小麦籽粒作出蓝色标记。观察到在 phlb 基因作用下,多价体频率加大,有可能使部分同源染色体4D 和4E 配对、交换,使太谷核不育基因(Tal)和4E 染色体上的蓝色胚乳基因连锁。从中得到少量中蓝色的全不育株行,其中 Tal 基因和     

phlb基因在中国春Tal kr phlb基因综合体与Agropyron intermedium杂…

本文对中国春Ｔａｌ ｋｒ ｐｈｌｂ基因综合体，Ｔａｌ中国春与Ａｇ．ｉｎｔｅｒｍｅｄｉｕｍ杂种Ｆ１花粉母细胞减数分裂中期Ｉ染色体配对情况进行了比较研究。证明ｐｈｌｂ基因可以诱导普通小麦与Ａｇ．ｉｎｔｅｒｍｅｄｉｕｍ间部分同源染色体配对，交换，从而有可能以染色体易位的方式把Ａｇ．ｉｎｔｅｒｍｅｄｉｕｍ中的有益基因转移到普通小麦中。在Ａｇ．ｉｎｔｅｒｍｅｄｉｕｍ（葡萄牙），Ａｇ．ｉｎｔｅｒｍｅｄｉｕｍ（     

ph1b基因在普通小麦与Ae.ovata(T.ovatum)杂交中的作用

中国春 phlb 突变体、中国春与 Ae.ovata 杂种 F_1花粉母细胞减数分裂中期Ⅰ每个细胞染色体交叉数分别为12.882和0.983个。说明,phlb 基因在普通小麦与 Ae.ovata 杂种中具有强的诱导部分同源配对的作用。在中国春 phlb 突变体×Ae.ovata 中有四价体、五价体及单价体少于14的细胞出现,说明 phlb 基因可以诱导普通小麦与 Ae.ova     

Ph1b基因在小麦品种间杂交中的利用及其转育(摘要)

实验结果从理论、细胞学和实践上表明,phlb基因在小麦品种间杂交通过诱导部分同源染色体配对形成多价体后产生染色体数目的增减和结构的变异(重组、易位和倒位等)增加性状遗传变异类型和幅度,从中能选育出一般品种间很难或不能得到的优异材料(品种)。但是phlb基因的遗传背景是农艺性状差的中国春,不利于phlb基因在育种上……     

ph1b、ph2a、ph2b基因在小麦与卵穗山羊草、小伞山羊草、离果山羊草F1杂种中的作用

迄今为止,仅Sharma等1986年研究报道了phlb基因诱导小麦与离果山羊草F₁杂种染色体配对作用,但没有在离果山羊草及其它山羊草中发现染色体配对促进基因或抑制基因,尚无phlb基因诱导小麦与卵穗山羊草F₁及ph2a、ph2b基因诱导小麦与这3个山羊草F₁染色体配对作用的报道。Farooq等1990年报道易变山羊草不同品系影响F₁染色体配对。     

phlb 基因对普通小麦×易变山羊草Ae.variabilis杂种F1、BC1、BC2、BC3及转移抗禾谷类根结线虫 M.naasi基因影响的研究

Courtot 4 phlb、Courtot 2 phlb、Courotot与 Ae.variabilis杂种F_1平均每PMC在MI染色体交叉数(Xta)分别为15.18、11.62、1.67。杂种F_1育性极差,自交不结实。Courtot 4phlb、Courtot 2 phlb与Ae.variabilis杂种F_1回交难,回交结实率仅分别为0.13％、1.66％;BC_1植株染色体少,93.1％的植株为2n=35-44,且减数分裂行为极不规则。在2phlb×Ae.variabilis×2phlb×Ph×Ph BC_3群体中可获遗传性较稳定、育性较正常、对 M.naasi抗性一致的重组系或易位系。而Courtot×Ae.variabilis杂种F_1回交较易成功（6.81％）。93.8％的BC_1植株染色体数变化在2n=47-56,BC_3中仅获抗M.naasi单体附加系。     

普通小麦同源转化群3在染色体配对及可交配性方面的作用

米勒(Miller)等研究了中国春同源转化与群3黑麦(Secaleceral L)及球茎大麦(Hbulbosum)的杂种和普通小麦同源转化群3,非整倍单倍体的不同染色体配对水平。结果发现,普遍小麦同源转化群3染色体的长臂和短臂上都带有影响染色体配对的基因。     

小麦地方品种“开县罗汉麦”在远缘杂交中的遗传评价

普通小麦(Triticum aestivum L.)是由A, B, D染色体组组成的六倍体物种。虽然这3个染色体组间存在部分同源关系,但是减数分裂中期的染色体配对只发生在同源染色体之间。这是由于普通小麦存在Ph(即Pairing homoeologous)配对调控系统。这个配对控制系统也同样抑制普通小麦与其外源属种的部分同源染色体间的配对,这也就阻碍了     

SSR标记定位一个新的小麦白粉病抗性基因

来源于簇毛麦与普通小麦杂交后代的稳定小麦品系101-3含有1个新的抗白粉病显性基因,暂命名为PmX,用单体分析的方法已定位于染色体6B上.以感白粉病小麦品种中国春与101-3杂交后代F2 为材料,用65对6B染色体上和9对6A染色体上小麦微卫星引物,进行连锁分析,发现小麦微卫星标记Xgwm570与基因的遗传距离为(9.72±2.40) cM,该结果表明,该基因位于小麦染色体6BL上,同时也为分子标记辅助育种上利用该基因提供了初步的选择标记.     

中间偃麦草抗小麦白粉病基因导入及其抗性评价

为利用中间偃麦草对小麦白粉病的抗性,通过八倍体小偃麦TAI7045与普通小麦杂交、回交,育成一批兼抗我国黄淮麦区和西南麦区小麦白粉病、条锈病的新品系和新材料。抗性评价结果表明,无论苗期还是成株期,对小麦白粉病菌优势小种E09及强毒力小种E20、E21表现为免疫或高抗的有57份,占测试材料的67.9%;中抗的有10份,占11.9%,且对白粉病的抗性来自中间偃麦草。对随机选取的4份抗病品系及其与普通小麦的杂交F1进行了根尖细胞有丝分裂中期染色体计数和花粉母细胞减数分裂中期I(PMC MI)染色体构型分析,结果表明,它们的染色体数目均为2n=42,4个材料及其与中国春杂交F1的平均染色体配对构型分别为0.13Ⅰ+19.75Ⅱ+0.06Ⅲ和0.16Ⅰ+20.06Ⅱ+0.04Ⅲ,而且与中国春小麦的染色体配对构型无显著差异,说明它们的染色体组成与普通小麦基本一致,在遗传学和细胞学上已具有良好的稳定性。     

Substituting Ability of Individual Barley Chromosomes for Wheat Chromosomes 1. Substitutions Involving Barley Chromosomes 1, 3 and 6

In order to determine the genetic relatedness of individual barley chromosomes to wheat chromosomes, ‘Betzes’ barley chromosomes 1, 3 and 6 were substituted for individual ‘Chinese Spring’ wheat chromosomes of homoeologous groups 7, 3 and 6, respectively. The substitution status of these lines has been confirmed using isozyme selective markers, chromosome pairing behaviour in F₁ hybrids between the substitution lines and the appropriate double ditelocentric stocks of wheat, and hybridization of cDNA probes to the genomic DNA digests of these substitution lines. Each of the three barley chromosomes provided genetic compensation for the wheat chromosomes they replaced in the substitution plants. From the basis of this compensation with respect to plant vigour and fertility, barley chromosomes 1, 3 and 6 have been designated 7H, 3H and 6H.     

Transfer of high kernel weight and high protein from wild tetraploid wheat (Triticum turgidum dicoccoides) to bread wheat (T. aestivum) using homologous and homoeologous recombination

Summary Wheat pentaploids were produced by hybridizing a high kernel weight (1000 grain wt=56 g), high protein (25.4%) line of wild tetraploid wheat (Triticum turgidum dicoccoides) as male parent, with the three hexaploids (T. aestivum) — normal Chinese Spring and its two homoeologous pairing mutants, ph _1b and ph ₂. The pentaploids were crossed as female parents to the two commercial hexaploid cultivars Warigal and Barkaee and 42-chromosome stable plants selected from the F₁ of the pentaploid x hexaploid crosses.Mean protein content of certain F₃ lines from all six pentaploid x hexaploid crosses was significantly higher than Chinese Spring and the respective commercial hexaploid parent (p<0.005) indicating high protein had been transferred from the tetraploid to the hexaploid level.Kernel weight amongst certain F₃ lines of the three pentaploids x Barkaee was significantly (p<0.0005) higher than either Chinese Spring or Barkaee, indicating the transfer also of high kernel weight from the tetraploid to the hexaploid level. However kernel weight was not significantly increased over Warigal in any F₃ lines of its crosses with the three pentaploids.High levels of homoeologous chromosome pairing in the ph-mutant pentaploids, plus evidence for significant modification of the composition of high-molecular weight (HMW) glutenin subunits of grain protein in certain F₃ derivatives of the ph-mutant pentaploid x hexaploid, crosses indicates that the ph-mutant-derived lines may possess novel (intergenome) genetic recombination, at least for high protein, and possibly kernel weight.     

Hybrids of Bread Wheat (Triticum aestivum) with Thinopyrum scirpeum (4x) and Thinopyrum junceum (6x)

Hybrids were obtained by crossing Thinopyrum scirpeum (4x) and T. junceum (6x) onto Triticum aestivum cv, ‘Chinese Spring’. An average meiotic pairing of 24.44^I+ 5.07^II+ 0.14^IIIin the ‘Chinese Spring’×T. scirpeum hybrid (ABDE₁E²) is attributed to two similar genomes from T. scirpeum (E₁E₂E₃E₄). An average meiotic chromosome pairing in the other hybrid (ABDJ₁J₂E₃) was 31.70^I+ 3.80^II+ 0.90^III and is attributed to autosyndetic pairing between the three genomes of T. junceum.     

Intergeneric Transfer (Rye to Wheat) of a Gene(s) for Russian Wheat Aphid Resistance

An octoploid triticale was derived from the F, of a Russian wheat aphid-resistant rye, ‘Turkey 77’, and ‘Chinese Spring’ wheat. The alloploid was crossed to common wheat, and to ‘Imperial’ rye/‘Chinese Spring’ disomic addition lines. F₂, progeny from these crosses were tested for Russian wheat aphid resistance and C-banded. A resistance gene(s) was found to be associated with chromosome arm IRS of the ‘Turkey 77’ rye genome. A monotelosomic IRS (‘Turkey 77’) addition plant was then crossed with the wheat cultivar ‘Gamtoos’, which has the 1BL.1RS ‘Veery’ translocation. Unlike the IRS segment in ‘Gamtoos’, the ‘Turkey 77’-derived 1 RS telosome did not express the rust resistance genes Sr31 and Ar26, which could then be used as markers. From the F, a monotelosomic 1 RS addition plant that was also heterozygous for the 1BL. 1 RS translocation was selected and testerossed with an aphid-susceptible common wheat, ‘Inia 66’ Meiotic pairing between the rye arms resulted in the recovery of five euploid Russian-wheat-aphid-resistant plants. One recombinant also retained Sr31 and Lr26 and was selfed to produce translocation homozygotes.     

Introduction of allien variation into wheat by gene recombination. I. Crosses between mono V (5B) Triticum aestivum L. and Secale cereale L. and Aegilops columnaris zhuk.

An analysis is made of meiotic pairing of hybrids whether or not deficient in the chromosome V (5B) from crosses between Mono V (5B) T. aestivum var. Chinese Spring and Secale cereale and Aegilops columnaris. Transmission rates of deficiency are not equal for both combinations. Isochromosomes are found in the hybrid plants.5B deficiency allows the pairing and recombination between the chromosomes of wheat and those of the related species. Such deficiency may be a useful wheat breeding tool to introduce alien variation into such cultivated species.Effectiveness of 5B deficiency on meiotic pairing of the hybrids, measured as the increase of the proportion of complement paired, is 36–37% and 49–50% in the hybrids involving rye and Ae. columnaris respectively. Minimum percentages of the introduction of alien variation into wheat are established for the material investigated: 2% for rye and 28% for Ae. columnaris.Methods of utilisation of the 5B deficiency in a programme of wheat breeding are discussed and outlined.     

Effects of Wheat Chromosome 1D Telosomes on Hybrid Seed Development in Wheat × Rye Crosses

Pollination of ‘Chinese Spring,’ monosome 1D plants with rye results in failure of hybrid seed development in a proportion of the F₁ seeds corresponding to the transmission rate of the nullisomic 1D egg cells. Development and viability of these hybrid seeds closely resemble that normally observed in T. aurum× rye crosses. Using ‘Chinese Spring’ chromosome ID telosomic plants in crosses with rye, it was possible to illustrate that the observed effect was associated with the long arm of this chromosome.     

Nearly Total Absence of Homoeologous Pairing in a Hybrid between Tetraploid Hordeum chilense and Triticum aestivum

A hybrid between an induced tetraploid of Hordeum chilense (2n = 28 = H^chH^chH^chH^ch) and Triticum aestivum var. ‘Chinese Spring’ (2n = 42 = AABBDD) has been produced to test gene effects of this wild barley on homoeologous pairing in wheat. Cytological investigations in metaphase I have shown that the hybrid, which is perennial like H. chilense but morphologically more similar to the wheat parent, possesses the expected genome composition H^chH^ch ABD and a stable euploid chromosome number of 2n = 35. Pairing among the homologous H. chilense chromosomes was almost complete. The level of non-homologous chromosome association proved to be lower than the range of pairing known from euhaploids of ‘Chinese Spring’.     

Production and Cytogenetical Analysis of a Rye-Cytoplasmic Tetraploid Triticale

A rye-cytoplasmic tetraploid triticale was found in F_s progenies of crosses between tetraploid rye‘No 1323’and hexaploid triticale‘KT 77′. In the tetraploid triticale, two complete rye genomes and two mixed wheat genomes, consisting of the chromosomes 1A. 2A, 4A, 7A, 3B, 5B, and 6B are present. The rye cytoplasm did not affect stability of rye chromosome pairing during metaphase 1, since rye chromosomes participated in pairing irregularities just as did wheat chramosomes, even on a larger scale. The fertility of F₀, plants ranged from 0 to 75.6 %, always associated with high grain shrivelling. The analyzed pairing behaviour of induced triploid hybrids from crosses between the tetraploid triticale and diploid rye indicates the presence of at least one wheat-rye translocation in one of the investigated triploid plants.     

Susceptibility toFusarium culmorum (W.G.Sm.)Sacc. in wheat (Triticum aestivum L.) substitution lines

Summary The wheat substitution lines of Hope into Chinese Spring were assessed for their ability to survive infection byFusarium culmorum at the seedling stage. The results showed considerable variation between experiments in the percentage of survivors 14 days after germination of the infected seed. Both parental varieties proved to be susceptible to infection. Significantly more plants of Hope survived than Chinese Spring and line 4B was the least susceptible of the substitution lines. There were significantly fewer survivors from line 1A than Chinese Spring and the majority of other lines. The susceptibility of line 1A was not due to its grain colour but may be related to the physiological characteristics of the line.