普通小麦雄性不育系及其保持系花粉形态的扫描电镜观察

利用扫描电镜观察了4种细胞质类型普通小麦(T. aestivum)雄性不育系及其保持系共16个材料的花粉形态,结果表明:不同细胞质类型雄性不育系之间的花粉粒形状及花粉粒表面纹饰有一定的差异,但花粉粒的大小、花粉粒萌发孔特征与不育细胞质类型无相关关系。不育系与其保持系在花粉粒形状、花粉粒表面纹饰方面也存在着明显的差异。     

八倍体小黑麦与普通小麦杂交的细胞遗传

八倍体小黑麦与普通小麦杂交,后代可以出现亲本类型八倍体小黑麦、普通小麦和普通小麦附加黑麦染色体异附加系与异代换系,对改进八倍体小黑麦的株高、熟期、结实率、籽粒饱满度有一定的效果,也可以选育抗病、耐旱较亲本增产的普通小麦新品种。细胞学观察结果:F₁染色体基本型为21_Ⅱ+7_Ⅰ,F相似文献   

3种不同倍性黑麦类作物种子形态比较和叶表皮显微观察

对3种不同倍性黑麦类作物进行染色体数目鉴定、种子形态观察和叶表皮超微结构观察。染色体数目鉴定结果显示,3种不同倍性黑麦类作物——二倍体黑麦(RR)、六倍体小黑麦(AABBRR)、八倍体小黑麦(AABBDDRR)染色体数目分别为14、42和56。不同倍性黑麦类作物种子大小、种子外形和种皮形貌存在明显的不同,叶表皮细胞结构没有明显差异,但叶片气孔器大小有显著的差别。研究表明,不同倍性黑麦类作物种子形态和叶片气孔器的差异可以作为不同倍性黑麦类作物间差异鉴定的重要参考依据之一。     

普通小麦×八倍体小黑麦杂种F1代与亲本的形态学、细胞学和超微形态比较分析

以普通小麦京冬8号为母本,八倍体小黑麦劲松5号为父本,杂交获得杂种F1代。在对杂种F1代和亲本进行形态学和细胞学鉴定的基础上利用扫描电子显微镜对亲本和杂种F1代的叶表皮及气孔亚显微形态进行比较,得知3种供试材料叶表皮亚显微形态共同的特征是有气孔器、长细胞和毛细胞,细胞排列与叶脉平行,但母本普通小麦的叶表皮细胞轮廓清晰,排列较为整齐、光滑,气孔排列呈直线,哑铃状的保卫细胞有长短不一的刺毛;父本八倍体小黑麦的气孔周围有横向和纵向排列的嵴状凸起,气孔呈长方形、较大,排列方式总体也呈直线型,保卫细胞非常明显,但刺毛极少且短;杂种F1代无论是叶表面还是气孔的亚显微形态都与父本更相似,所不同的是叶表皮有刺毛,气孔大小介于两亲本之间。杂种F1代与双亲在形态学、叶表皮及气孔超显微形态特征上均有明显差异;超显微形态学指标也可以作为区分、鉴定远缘杂种和亲本的一项依据。     

利用黑麦颈毛基因和抗白粉病性结合细胞学鉴定选育小黑麦附加系和代换系简报

利用黑麦颈毛基因和抗白粉病性结合细胞学鉴定选育小黑麦附加系和代换系简报海林，马缘生（中国农业科学院作物品种资源所；北京１０００８１）利用小麦与黑麦杂交将黑麦的优良性状导入小麦，既可创造小黑麦新物种，又可改良小麦旧物种，得到具有某些黑麦优良特点或超亲特...     

390份小麦-黑麦种质材料主要农艺性状分析及优异材料的GISH与FISH鉴定

将小麦近缘属植物黑麦中的优良基因导入小麦可以拓宽小麦的遗传基础,丰富小麦的遗传变异。本研究调查并分析了390份小麦-黑麦种质材料。在这390份种质材料中,6个主要农艺性状值均有较大的极差,说明其遗传多样性丰富。与10份小麦主栽品种相比,90%以上的材料具有穗长和分蘖数的显著优势,60%以上的材料具有小穗数优势,约30%的材料穗粒数和千粒重显著高于主栽品种。利用基因组原位杂交(genomic in situ hybridization,GISH)和多色荧光原位杂交(multicolor fluorescent in situ hybridization,mc-FISH)技术,对8份农艺性状优良的代表性材料进行染色体组成分析,发现3份为六倍体小黑麦(AABBRR),2份为八倍体小黑麦(AABBDDRR),1份为1RS·1BL易位系,其余2份不具有可见的黑麦染色体或染色体片段。值得指出的是,3份六倍体小黑麦与2份八倍体小黑麦所含的黑麦染色体不完全相同。八倍体小黑麦中有1对来源于黑麦的小染色体,而六倍体小黑麦中没有类似小染色体;并且,不同材料中黑麦4R染色体端部的GISH杂交带有明显差异。本研究结果为这些小麦-黑麦种质材料进一步应用于小麦育种提供了依据。     

10个八仙花品种花粉粒形态扫描电镜观察

利用电镜扫描观察10个八仙花品种的花粉粒,根据花粉粒的形状、长短轴比、萌发沟特征、纹饰特征、极面特征等分析八仙花不同品种间以及孕性花粉粒形态特征的差异性.结果 表明,八仙花可孕花的花粉粒均为长球体,除了'无尽夏'和'奥塔克萨'不孕花花粉粒为超长球体外,其他也为长球体,均具3条萌发沟,沟长裂至两极,属于N3P4C5型花粉;花粉粒极面形状有差异,'无尽夏'、'奥塔克萨'、'蒙娜丽莎'、'头花'和'初恋'极面观为三裂圆形,其他品种极面观为钝三角形;不同品种花粉粒的萌发沟长度与萌发沟脊面宽也存在差异,仅'玫红妈妈'不同孕性花粉粒具有显著性差异.外壁纹饰均为孔穴状,其孔穴大小、形状以及分布特征不同,但是同一品种的不同孕性花粉粒形态特征并无差异.综上所述,花粉粒的外壁纹饰可作为八仙花品种鉴定的依据之一,但是不能作为花粉孕性的鉴别依据.     

小黑麦的营养品质和加工利用

小黑麦是第一个人工合成的新作物。它不仅保持了小麦的优良种子品质,而且还保持了黑麦的赖氨酸含量高等特点,同时还具有蛋白质含量高于小麦和黑麦双亲的新特性。因此小黑麦将为农业和畜牧业发展提供植物蛋白新来源,是一种粮饲兼用,很有发展前途的新作物。     

麦类种子贮存后遗传完整性的研究

该文以大麦、普通小麦、硬粒小麦、黑麦、小黑麦等5种麦类作物种子为试材,从个体、细胞、分子3个水平上探讨了不同贮存温度,不同包装材料和不同含水量对其遗传完整性的影响,为中、长期种子贮存提供“监测”指标。     

29份野生牡丹种质资源叶表皮微形态观察

为了解牡丹野生资源在叶表皮微形态方面的特征及差异,为牡丹野生资源的分类提供依据,本研究利用光学显微镜(LM)和扫描电子显微镜(SEM)对29份野生牡丹种质资源叶片的上、下表皮微形态特征进行了观察分析。结果表明：叶表皮细胞形状均为无规则形,但垂周壁式样有深波状、浅波状和波状3种,上表皮细胞长宽比2.38～4.99,下表皮细胞长宽比1.70～4.25;气孔分布在下表皮,气孔器均为无规则型,形状为椭圆形或宽椭圆形,长宽比1.18～1.55,气孔密度为162.1～331.6个/mm2,气孔指数8.95%～26.98%;叶表皮角质层多平滑、呈脊状突起或具颗粒状纹饰;卵叶牡丹居群1～4、稷山牡丹居群1-2、紫斑牡丹居群1～5和中原牡丹居群1叶表面具表皮毛,在叶下表皮或沿中脉集中分布。研究为牡丹组野生种植物学鉴定和分类提供了叶表皮微形态特征的基础资料。     

Pollen production in hexaploid triticale

Summary Comparative studies were made of the pollen characteristics of triticale, wheat, and rye. Measurements were made of the anther length, width, and percent extrusion; pollen viability; size and number of pollen grains per anther; and dispersal on 10-mm² slide area pollen traps. Triticale anthers were intermediate in length between and significantly different from both wheat and rye. Rye pollen grains per anther were four and two times greater in number than those of wheat and triticale, respectively. Pollen viability was not significantly different between species. Rye pollen grains were smaller than those of wheat and of some triticale cultivars. Simple correlations between anther length and anther width, pollen grains per anther, pollen grain trapped per 10 mm² slide area, and plant height were significantly positive.     

Pollen Longevity in Wheat, Rye and Triticale

The duration of pollen life was measured for several varieties of wheat, rye and triticale to determine whether the inclusion of alleles for pollen longevity from alien sources would be necessary and effective in hybrid wheat production. Percent seed set was calculated from spikes in which emasculated flowers had been pollinated with pollen stored for specified time intervals under desiccation and under normal greenhouse conditions. Seed was set on wheat, rye and triticale lines using pollen stored for 45, 220, and 80 minutes, respectively. These results indicate that the duration of wheat pollen life is adequate for fertilization to occur under conditions normally used in hybrid wheat production, and that. Introgression of alien alleles is not necessary.     

Histological studies on the infection of triticale,wheat and rye byPuccinia recondita f.sp.tritici andP. recondita f.sp.recondita

Summary The reaction of eight triticales and of the respective wheat and rye parental lines to infection by the leaf rust fungi of wheat and rye were studied in the seedling stage. The histological observations indicated that wheat and triticale showed a typical nonhost reaction to the leaf rust of rye: sporelings of this fungus were arrested after the formation of primary infection hyphae and before the formation of extensively branched mycelium, mostly without necrosis of plant cells. The rye inbred lines were all susceptible to the rye leaf rust. The reaction of wheat and triticales to the wheat leaf rust was susceptible or resistant. The reaction of resistant lines could be early or late and complete or incomplete, but was associated with substantial necrosis of plant cells, and therefore entirely different from the nonhost reaction to rye leaf rust. In their reaction to wheat leaf rust the rye lines were similar to the resistant wheat and triticale lines. They did not show an important degree of nonhypersensitive early abortion as would be expected in a nonhost species. It appeared that genes for hypersensitive resistance in triticale may be contributed by either the wheat or the rye parental line.A screening of sixty wheat, rye and triticale lines confirmed the nonhost status of wheat and triticale to rye leaf rust and the hypersensitive or moderately susceptible reaction of rye to wheat leaf rust.     

Effects of genotype and genotype—environment interaction on deoxynivalenol accumulation and resistance to Fusarium head blight in rye, triticale, and wheat

Fusarium culmorum is one of the most important Fusarium species causing head blight infections in wheat, rye, and triticale. It is known as a potent mycotoxin producer with deoxynivalenol (DON), 3‐acetyl deoxynivalenol (3‐ADON), and nivalenol (NIV) being the most prevalent toxins. In this study, the effect of winter cereal species, host genotype, and environment on DON accumulation and Fusarium head blight (FHB) was analysed by inoculating 12 rye, eight wheat, and six triticale genotypes of different resistance levels with a DON‐producing isolate at three locations in 2 years (six environments). Seven resistance traits were assessed, including head blight rating and relative plot yield. In addition, ergosterol, DON and 3‐ADON contents in the grain were determined. A growth‐chamber experiment with an artificially synchronized flowering date was also conducted with a subset of two rye, wheat and triticale genotypes. Although rye genotypes were, on average, affected by Fusarium infections much the same as wheat genotypes, wheat accumulated twice as much DON as rye. Triticale was least affected and the grain contained slightly more DON than rye. In the growth‐chamber experiment, wheat and rye again showed similar head blight ratings, but rye had a somewhat lower relative head weight and a DON content nine times lower than wheat (3.9 vs. 35.3 mg/kg). Triticale was least susceptible with a five times lower DON content than wheat. Significant (P = 0.01) genotypic variation for DON accumulation existed in wheat and rye. The differences between and within cereal species in the field experiments were highly influenced by environment for resistance traits and mycotoxin contents. Nevertheless, mean mycotoxin content of the grain could not be associated with general weather conditions in the individual environments. Strong genotype‐environment interactions were found for all cereal species. This was mainly due to three wheat varieties and one rye genotype being environmentally extremely unstable. The more resistant entries, however, showed a higher environmental stability of FHB resistance and tolerance to DON accumulation. Correlations between resistance traits and DON content were high in wheat (P = 0.01), with the most resistant varieties also accumulating less DON, but with variability in rye. In conclusion, the medium to large genotypic variation in wheat and rye offers good possibilities for reducing DON content in the grains by resistance selection. Large confounding effects caused by the environment will require multiple locations and/or years to evaluate FHB resistance and mycotoxin accumulation.     

Comparative Study on the Effect of Water Stress on the Photosynthesis and Water Relations of Triticale, Rye and Wheat

An attempt was made to investigate the effect of water stress treatment on the components of photosynthesis and water relations of triticale ( Triticale octoploide ), Russian rye ( Secale cereale ) and wheat, ( Triticum aestivum var. Sonalika ). The results revealed that there was no significant adverse effect of water stress on the photosynthesis of triticale compared to wheat and rye. The maintenance of photosynthetic productivity under water stress in triticale has been accomplished by (a) reduction in water loss by stomatal behaviour and (b) by maintenance of water uptake through continued transpirational flow. Both these mechanisms served to maintain high water potential as stress occures. This ameliorates the onset of stress and helps to maintain photosynthesis. The rye also consists of another type of adaptability to drought through significant recovery of photosynthesis and chlorophyll development on reirrigation particularly at post-anthesis stage, when other species failed to recover. However, in wheat Sonalika both these adaptive characteristics did not exist in such intensity.     

Triticale,Still a Promise?

Experiments with primary triticale genotypes produced from defined wheat and rye parents provide a strong indication of a preponderance of specific genome combining ability in the phenotypic expression of triticale. Studying line families developed from specific cross combinations by means of the single seed descent method revealed that, in contrast to wheat, the distribution of genotypes in an F₂ population of triticale is strongly skewed, with the majority of them being inferior to the mid-parent value. This is the case even if recombination is restricted to one fourth of one of the parental components of triticale, i.e. wheat or rye. Correlations of yield components were found to deviate substantially from known types of correlations in wheat, an established natural allopolyploid species. These findings give a strong indication for a genomic inbalance in triticale being a major cause for slow advance in varietal improvement. New breeding strategies designed for the specific genetic structure of triticale are necessary to accelerate breeding progress and to help triticale ultimately to live up to its promise.     

Heterosis in Primary Hexaploid Triticale with Heterozygous Wheat or Rye Genome*)

Twelve primary hexaploid triticale (X Triticosecale Wittmack), synthesized from, three lines of tetraploid wheat (Triticum durum L., T. turgidum L.) and four inbred lines of rye (Secale cereale L.), were used to produce 18 crosses with homozygous wheat and heterozygous rye genome and 12 crosses with heterozygous wheat and homozygous rye genome. Parents and crosses of triticale, wheat, and rye were tested for two years (rye for one year only) in two-replicate block designs with 1 m²-plots. Data were assessed for plant height, grain yield and for yield-related traits. Performance of triticale crosses was considerably lower than that of the wheat and rye crosses. The amount of heterosis varied greatly between years. Positive and mainly significant heterosis was revealed in triticale generations F₁ and F₂. The average values were closer to those in wheat than to those in rye. For most characters a high level of heterosis was retained in tnucalt1 generation F₂. Heterozygosity of the wheat and rye genome both contributed to heterosis in triticale. However, gene action of the rye genome strongly depended on the homozygous wheat background: one wheat line almost completely suppressed and another greatly stimulated the heterotic effect of the rye genome. In the later case, the amount of heterosis was related to that in rye per se. Information from hybrid rye breeding may therefore be used when establishing gene pools for hybrid breeding in triticale.     

Reaction of triticale,wheat and rye accessions to graminaceous Fusarium spp. infection at the seedling and adult plant growth stages

Summary Pathogenicity of 20 isolates of 12 Fusarium species recovered from triticale seed against seedlings of 14 varieties of winter cereals (triticale, wheat, and rye) was tested. The most pathogenic inoculum was a mixture of isolates (a composite isolate) of all the species. The following species were individually the most pathogenic: F. avenaceum, F. culmorum, F. sambucinum var. coeruleum, and F. graminearum. Winter triticale was more resistant to seedling blight than rye but more susceptible than wheat.Also reactions of 31 winter and 12 spring varieties of cereals to head inoculation with a composite isolate of 4 Fusarium spp. (F. avenaceum, F. culmorum, F. graminearum, and F. sambucinum var. coeruleum) was studied. In comparison to other cereals of similar type winter and spring wheat appeared to be the most susceptible while winter rye reaction was comparable to winter triticale. Spring and winter triticale varieties responded to head infection intermediately.There was no significant correlation between seedling and head reactions to infection with Fusarium spp. for winter rye and triticale. For winter wheat a negative trend was found. The above findings imply that screening of cereals at the seedling stage can not be used to predict the resistance to head blight. Nevertheless, resistance at the stage is highly desirable to prevent excessive damage of the crops due to the seedling blight incited by Fusarium spp..     

Comparison of rye,triticale, durum wheat and bread wheat genotypes for Fusarium head blight resistance and deoxynivalenol contamination

Small-grain winter cereal crops can be infected with Fusarium head blight (FHB) leading to mycotoxin contamination and reduction in grain weight and quality. Although a number of studies have investigated the genetic variation of genotypes within each small-grain cereal, a systematic comparison of the winter crops rye, triticale, durum and bread wheat for their FHB resistance, Fusarium-damaged kernels (FDK) and deoxynivalenol (DON) contamination across species is still missing. We have therefore evaluated twelve genotypes each of four crops widely varying in their FHB resistance under artificial infection with one DON-producing F. culmorum isolate at constant spore concentrations and additionally at crop-specific concentrations in two environments. Rye and triticale were the most resistant crops to FHB followed by bread and durum wheat at constant and crop-specific spore concentrations. On average, rye accumulated the lowest amount of DON (10.08 mg/kg) in the grains, followed by triticale (15.18 mg/kg) and bread wheat (16.59 mg/kg), while durum wheat had the highest amount (30.68 mg/kg). Genotypic variances within crops were significant (p ≤ .001) in most instances. These results underline the differing importance of breeding for FHB resistance in the different crops.     

Identification of rye genotypes resistant to biotypes B,C, E,and F of the greenbug

Summary The greenbug, Schizaphis graminum (Rondani), is a serious pest of wheat, Triticum aestivum L., and other small grains. Cultivar resistance would be an efficient means of control. Unfortunately, a paucity of greenbug resistance in wheat germplasm and occurrence of new virulent biotypes of the greenbug have made development of resistant cultivars difficult. Therefore, resistance genes are sought in species related to and crossable with wheat. Our objective was to evaluate, in greenhouse seedling tests, 11 rye (Secale cereale L.) accessions for their reaction to greenbug biotypes B, C, E, and F. Two ryes, CI 187 and PI 240675, segregated for resistance to all four biotypes. It may be possible to transfer this resistance to wheat. These resistance sources may also be of importance in rye and triticale (X Triticosecale Wittmack) breeding.