不同激素培养基对小麦×玉米杂种幼胚发育的影响

本研究结果表明，采用２，４－Ｄ浸穗法结合低浓度激素培养进行小穗培养，可以明显改善小麦和玉米杂交种颖果、幼胚及胚乳的发育状况，得胚率由２．１％提高到１２．０％；同时表明低浓度激素对杂种发育有着明显的调节作用，但２，４－Ｄ和ＧＡ优于ＫＴ。     

中国春小麦(6x)×苏联球茎大麦(4x)属间杂交的研究初报

本试验选用抗病性较强的球茎大麦(2n=28)为父本,以普通小麦(2n=42)为母本,进行属间杂交,授粉24小时后,在母本柱头上滴赤霉酸,促使幼胚生长,以中国春单体5B 为母本杂交,获得了少量结实的杂交种子;以中国春为母本的,则结合离体培养杂种幼胚,以获得属间杂种。杂种自花不育,而以中国春单体5B 与之回交,获得三株回交一代杂种(B相似文献   

普通小麦(Triticum aestivum)和毛穗赖草(Leymus paboanus)的杂交,杂种细胞无性系的建立及植株再生

以3个普通小麦品种富可(Fuhuko)、中国春(Chinese Spring)及小偃759和毛穗赖草杂交,发现三个品种都可与毛穗赖草杂交,其中Fuhuko×L.paboanus平均结实率高达17.6％,杂种只有发育不全的幼胚而无胚乳。对杂种幼胚在N_6+1—2mg/11BA+0.5mgGA_3或MS(其中NH_4NO_3含量降低一半)附加1mg/1IBA的培养基上进行保姆培养,部分幼胚发育成     

小麦与玉米杂交产生小麦单倍体与双单倍体的稳定性

小麦与玉米杂交是诱导小麦单倍体最有效的途径之一, 但单倍体和双单倍体产生频率不稳定影响了该技术的应用。选用13个小麦杂种F₁代单交组合与玉米杂交, 研究了不同小麦生长环境、生长素处理、培养基和壮苗处理对单倍体及双单倍体产生频率的影响。小麦生长在大田, 去雄后割穗培养与玉米杂交平均得胚率为23.9%, 每个杂交穗平均得胚数6.8个, 均是返青后从大田移回冷温室盆栽的3倍以上;不同小麦杂交组合间胚产生频率存在明显差异。生长素Dicamba蘸穗处理平均得胚率是21.5%, 与2,4-D处理得胚率(21.1%)无显著差异, 但不同杂交组合间差异显著。B5培养基幼胚萌发率为70.9%~88.3%, 平均82.0%;1/2 MS培养基胚萌发率为70.0%~86.0%, 平均76.6%;两种培养基平均胚萌发率无显著差异。试管苗经壮苗培养基壮苗处理与试管苗经移栽壮苗处理后加倍效率分别是67.6%和8.6%。移栽壮苗处理的苗分蘖少, 生长较弱, 加倍处理后存活率低和加倍率低是其单倍体加倍效率低的原因。     

VB1和干燥处理对小麦幼胚愈伤组织培养的影响

以14个小麦品种为试验材料，研究不同浓度维生素B1和分化前的干燥处理对小麦幼胚愈伤组织诱导、分化过程的影响。结果表明，小麦幼胚愈伤组织的分化率在不同基因型之间差异显著，其中最高的为郑新992(71．9％)；在愈伤组织诱导、继代以及分化培养的Ms培养基中添加维生素B1(盐酸硫胺素)10mg／L有利于小麦幼胚胚性愈伤组织的发生，同时对促进小麦幼胚愈伤组织的分化也有显著影响；在转入分化培养基前对愈伤组织进行干燥处理(12h)可有效提高其分化频率。     

多效唑在小麦组织培养中的应用研究

组织培养已成为小麦育种工作中系重要的辅助手段之一.许多科学家在小麦远缘杂交中利用幼胚培养抢救杂种胚或体细胞无性系变异创造新种质.一些育种机构应用花药培养缩短杂种后代分离期育成了小麦新品种.在我国北部冬麦区,小麦的花药培养以及幼胚幼穗培养大都始于4—5月,直到秋季天气较冷时移栽到温室或大田.再生植株在长时间的越夏培养中,往往表现生长弱,根系不发达,移栽时成活率低,很难满足育种对群体的需要.一些基     

小麦与大麦杂种幼胚离体培养研究

小麦和大麦是世界上两大麦类栽培作物，二者亲缘关系较远，杂交极不易成功。本文通过生物组培技术，将杂种幼胚离体培养获得杂交种，从而克服小、大麦远缘杂交不育性，把大麦的优良性状引入小麦，对小麦育种有重要意义。     

普通小麦与野生大麦的属间杂交

通过活体/离体幼胚培养获得了智利大麦(Hordeum chilense,2n=2x=14)、海大麦(H.marinum,2n=2x=14)及平展大麦(H.depressum,2n=4x=28)与普通小麦(Triticum aestivum,2n=6x=42)之间的属间杂种。智利大麦×小麦及海大麦×小麦杂种在形态上偏向父本小麦,而平展大麦×小麦杂种除穗部性状外,其形态明显偏向母本。所有杂种均自交不孕     

小麦×羊草远缘杂交的受精和胚胎发育

对小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｎＬ）和羊草（ＬｅｙｍｕｓｃｈｉｎｅｎｓｉｓＴ．）杂交的受精和胚胎发育进行了研究。羊草花粉在小麦柱头上萌发较好，花粉管能顺利穿过柱头，进入胚囊。在检查过的３１０个子房中，１７个（５．５％）发生了双受精，产生了胚和胚乳；２个（０．６５％）发生了单卵受精，只产生胚而无胚乳；７个（２．２６％）发生了单极核受精，只产生胚乳而无胚。小麦×羊草虽然受精率为８．４１％，但最后结实率很低，若利用胚培养技术对杂种胚进行早期离体培养，可望提高杂种植株的获得率     

AgNO_3在小麦幼胚组织培养中的应用研究

为了提高小麦幼胚体细胞再生频率,以河南省大面积推广的豫麦49号、豫麦18号和兰考906为研究对象,研究了不同浓度AgNO_3对小麦幼胚胚性愈伤组织培养特性和草酸盐氧化酶活性的影响.结果表明:基因型间、不同AgNO_3浓度间小麦幼胚胚性愈伤组织诱导率、愈伤组织绿点率和草酸盐氧化酶活性差异均达到0.01显著水平,基因型间以豫麦18最高、兰考906最低;不同AgNO_3浓度间以MS培养基上附加2.5～5.0 mg/L处理较高.不同浓度AgNO_3条件下小麦幼胚胚性愈伤组织诱导率与草酸盐氧化酶活性相关系数为0.920,达0.01显著水平.可见,在小麦幼胚组织培养过程中可以加入Ag~+提高再生频率.     

Wheat embryogenesis and haploid production in wheat × maize hybrids

Summary Embryogenesis was analyzed in wheat × maize hybrids using paraffin sectioning. Embryogenesis in wheat × maize hybrids is different from that in self-pollinated wheat plants. Development of the embryo is not accompanied by the formation of an endosperm. The endosperm nuclei remain free in the cytoplasm, fail to advance into the cellular stage, and degenerate at a later time. The antipodal cells quickly degenerate in the fertilized ovaries of wheat × maize hybrids similar to self-pollinated ovaries. The antipodal cells remain normal in unpollinated ovaries. The pre-embryo will abort if it is allowed to develop on the plant, because of a nutritional shortage in the absence of an endosperm. Therefore, embryo rescue is necessary for haploid production from a wheat × maize hybrids. Haploid polyembryos were obtained from spikelet culture of wheat × maize hybrids. The formation of polyembryos is due to the cleavage of the pre-embryo and the effect of 2,4-D. The frequency of haploid embryo production and plant regeneration is affected significantly by maize genotypes, but not by wheat genotypes. The concentration of 2,4-D affects only the size of the embryo.     

The effect of spikelet position on the success frequencies of wheat haploid production using the maize cross system

Barbela is an old Portuguese landrace of wheat that is highly genetically heterogeneous. Different Barbela populations when subjected to aluminium stress show variable levels of tolerance. In order to study the inheritance of this character, doubled haploid (DH) lines were developed. These DH were obtained by intergeneric crosses of 14 different lines of Barbela with maize. During this process the efficiency of the technique was evaluated and suggestions for its improvement were obtained. Several parameters were studied in the crosses: % of crossability, % of embryos per florets pollinated and % of embryos per seed set. The different genotypes of Barbela showed significant variation for the parameters analysed. When the reciprocal crosses were analysed, no differences were found, indicating that cytoplasm differences do not influence the parameters of DH production. However, different spikelet positions (lower, middle and upper) gave highly significant differences in all parameters analysed. Highest success frequencies were obtained for pollinated spikelets in the middle of the spike. This can indicate that concentrating on the middle part of the spike can increase the frequency of DHs obtained using inter generic crosses of wheat with maize. This revised version was published online in August 2006 with corrections to the Cover Date.     

Variation of the crossability of durum wheat with maize

With the aim of examining crossability of durum wheat with maize, two sets of durum wheat genotypes and a set of D-genome chromosome substitution lines of the durum wheat variety ‘Langdon’ were crossed with maize, and followed by 2,4-dichlorophenoxyacetic acid (2,4-D) treatment in detached-tiller culture. In crosses of 25 durum wheat genotypes (breeding lines) with maize, percent frequencies of embryo formation increased from 1.4% to 2.8% by adding silver nitrate to the detached-tiller culture solution. In crosses of 32 durum wheat genotypes (advanced lines and varieties) with maize using the silver nitrate addition, frequencies of embryo formation ranged from 0.0% to 15.8%; seven genotypes showing more than 6.0% embryo formation frequency were related in their pedigrees. In crosses of a set of chromosome substitution lines with maize, higher frequencies of embryo formation were obtained in substitution lines with chromosomes 1D, 3D, 4D and 7D. These results suggest that 1) adding silver nitrate to the 2,4-D treatment increases overall frequency of embryo formation but is not effective enough to induce the development of seeds and embryos from all durum wheat genotypes, and 2) some D-genome chromosomes substituted in a durum wheat genetic background may enhance crossability with maize in combination with homoeologous chromosomes of durum wheat. This revised version was published online in August 2006 with corrections to the Cover Date.     

Grass inflorescence and spikelet culture: An appraisal

Summary Techniques of inflorescence and spikelet culture have been used for three major cereals. In maize, the influence of hormones on sexuality has been demonstrated. For wheat and barley the influence of supplying carbohydrate and nitrogen on grain content has been explored. Although in vitro seed setting is less efficient than in vivo the resulting grains, from optimal treatments, are in almost all respects normal or nearly so. Culture media to achieve this are precisely defined.In reviewing this work a major concern has been to highlight an elegant system of enquiry but at the same time to indicate the remarkably small area of interest to which it has been applied. As a prelude therefore to a consideration of the technical achievements, the range of spikelet form, and more particularly, function are examined. The aim is to encourage the application of inflorescence and spikelet culture to a much wider range of topics than hitherto.     

西藏三联小穗小麦中三联小穗性状控制基因的SSR分子标记定位

西藏三联小穗小麦是中国西藏地区一种独特的小麦地方品种,拥有特殊的三联小穗性状,超多的小穗数和小花数。分子定位控制三联小穗基因的基因座,发掘与之紧密连锁的分子标记,可为小麦高产育种提供分子标记辅助选择工具。本研究利用西藏三联小穗小麦的衍生系TTSW-5与普通穗型小麦,间3和川麦55,分别构建F2群体,成熟后进行穗部性状的表型分析和SSR基因型鉴定。性状表型遗传分析表明,西藏三联小穗小麦的三联小穗性状由两个独立遗传的隐性基因控制;通过SSR标记鉴定来自TTSW-5/间3组合的F2群体,在2A染色体上检测到1个与三联小穗性状相关的QTL,定位于SSR标记Xgwm275和Xgwm122之间,两标记间的遗传距离为6.6cM,该QTL的LOD值为6.19,可解释的表型变异值为33.1%,初步命名为qTS2A-1。我们推测qTS2A-1可能是控制三联小穗性状相关的主效QTL,SSR标记Xgwm275和Xgwm122可能可用于三联小穗性状的辅助选择。     

培养基对小麦单倍体胚成苗率的影响

为筛选出适宜小麦单倍体幼胚生长的培养基,提高小麦单倍体胚成苗率,将小麦×玉米远缘杂交得到的小麦单倍体幼胚接种在8种培养基上,每种培养基上接种2个材料,平均值用于数据分析。8种培养基中幼苗平均产生率分别为：46.07%、45.90%、34.11%、41.15%、37.99%、36.91%、37.70%和52.51%。结果表明1/2MS +1.0 mg/L KT+3.0 mg/L多效唑+100 mg/L肌醇+5%蔗糖+0.6%琼脂,pH 5.8培养的幼胚成苗率最高,白化苗率低,且单倍体苗的长势较好,有利于培育壮苗。以1/2MS为基本培养基,加入微量的多效唑、KT、肌醇以及较高浓度的蔗糖可以有效促进幼胚生长。     

Relative Efficiency of Anther Culture and Chromosome Elimination Techniques for Haploid Induction in Triticale × Wheat and Triticale × Triticale Hybrids

Summary The study was undertaken to evaluate the relative efficiency of anther culture and chromosome elimination (by crosses with maize) techniques of haploid induction in intergenotypic triticale and triticale × wheat hybrids. For this, 15 triticale × wheat and 8 triticale × triticale F₁ hybrids were subjected to anther culture and were also simultaneously crossed with the `Madgran Local' genotype of maize (Zea mays L.) to induce haploids through the chromosome elimination technique. The haploid embryo formation frequency through the chromosome elimination technique was significantly higher in both, triticale × wheat (20.4%) and triticale × triticale (17.0%) F₁ genotypes, as compared to the calli induction frequencies through anther culture (1.6 and 1.4%, respectively). Further, four triticale × wheat and three triticale × triticale F₁ genotypes failed to respond to anther culture, whereas, all the F₁ genotypes formed sufficient number of haploid embryos through the chromosome elimination technique with no recovery of albino plantlets. The haploid plantlet regeneration frequencies were also significantly higher through the latter technique in both triticale × wheat (42.7%) and triticale × triticale (49.4%) F₁s as compared to anther culture (8.2 and 4.0%, respectively), where the efficiency was drastically reduced by several constraints like, high genotypic specificity, low regeneration frequency and albinism. The overall success rates of obtaining doubled haploids per 100 pollinated florets/anthers cultured were also significantly higher through the chromosome elimination technique (1.1% in triticale × wheat and 1.5% in triticale × triticale hybrids), proving it to be a highly efficient and economically more viable technique of haploid induction as compared to anther culture, where the success rates were only 0.2% and 0.1%, respectively.     

Inheritance of genes controlling supernumerary spikelet in wheat line 51885

The supernumerary spikelet character of bread wheat (Triticum aestivum L.) is an abnormal spike with extra spikelet per spike. Supernumerary spikelet line 51885 was derived from the cross between octoploid Triticale and common wheat Fei 5056. The number of spikelet is over 30, and supernumerary spikelet is genetically stable. The inheritance of supernumerary spikelets in the line 51885 was genetically analyzed by crossed with seven commercial cultivars of normal head type. The results indicated that supernumerary spikelet in the line 51885 was controlled by two dominant genes which shows complementary function. Transgressive segregation for increasing the number of spikelet were observed in the four crosses, suggesting the possibility of the presence of minor effect gene(s) or modification gene(s) affecting the expression of the supernumerary spikelet in addition to the two major dominant genes. The relatively simple inheritance, feature of dominance plus the stability of expression of supernumerary spikelet in the line 51885 indicate that line 51885 could be easily incorporated in high yield breeding program in common wheat.     

玉米雄穗性状的配合力及遗传参数研究

以7份具有不同雄穗性状的玉米自交系为材料，采用Griffing方法4的双列杂交，估算了玉米雄穗主轴长度、分枝数、平均分枝长度、小穗着生密度和每穗小穗数5个性状的一般配合力、特殊配合力和相应的遗传参数，并进行了性状间一般配合力相关分析。结果表明：5个雄穗性状一般配合力明显高于特殊配合力，基因累加效应占遗传主导地位；5个性状的hB^2(％)分别为80．72，82．96，85．13，84．211，61．10．hN^2(％)分别为60．92，66．11，44．62，67．20，38．96。性状间一般配合力效应相关分析发现，分枝数、小穗着生密度与每穗小穗数间分别呈极显著和显著正相关(r=0．9347^**，r=0．8345^*)。选择雄穗时，对分枝数、小穗着生密度宜进行早代选择。