八倍体小黑麦(Triticale)与六倍体小黑麦杂交若干问题的探讨

本工作以改进八倍体小黑麦与六倍体小黑麦的经济性状为目的,对60个杂交组合 F_1的田间出苗率、结实率、杂种后代的性状分离、新类型的形成以及细胞遗传的若干问题进行了探讨,观察到 F_1田间出苗率、结实率以八倍体为母本的杂交组合显著好于以六倍体为母本的杂交组合。由于杂种是普通小麦、硬粒小麦、黑麦三个物种种质的再度组     

Presto×晋农190杂种F_2-3及双亲的核型分析

为创制六倍体小黑麦(TriticosecaleWittmack)-普通小麦(Triticum aestivumL.)异染色体体系,将六倍体小黑麦的优良基因导入到普通小麦中,以六倍体小黑麦品种Presto为母本、普通小麦品种晋农190为父本,配置杂交组合,对双亲及其杂种F2种子根尖细胞进行有丝分裂观察,确定其染色体数目并进行核型分析。结果发现,双亲的染色体数目均为42,父本晋农190的核型公式为2n=42=36m(2SAT)+6sm,核型类型为1A;母本Presto的核型公式为2n=42=26m(4SAT)+4M+12sm,核型类型为2A。杂种F2中F2-3为双单体附加系,其核型公式为2n=44=36m(3SAT)+4sm+1m+1m,核型类型为1A。通过对染色体的形态、短臂和长臂的长度、臂比及相对长度系数进行分析,可初步推断杂种F-3附加的可能是母本的7号和21号染色体。     

四倍体小麦与六倍体小麦杂种的染色体遗传特性

四倍体栽培小麦(Triticum turgidum L., AABB)和普通小麦(Triticum aestivum L., AABBDD)是两种目前主要的小麦栽培种。通过远缘杂交转移利用四倍体小麦(或六倍体小麦)基因是六倍体小麦(或四倍体小麦)遗传改良的重要方法。然而,两者杂种F1为基因组组成不平衡的五倍体,其中A和B基因组染色体均为两套,而D基因组染色体仅一套。亲本间的遗传差异,包括核基因组和细胞质基因组,可能影响五倍体杂种的染色体传递效率。本研究以多个不同遗传背景的四倍体小麦和六倍体小麦为亲本,配置正反交五倍体杂种F1,采用多色荧光原位杂交技术分析自交F2代植株的染色体组成规律。结果表明,杂交亲本的遗传背景对杂种F1自交结实率影响显著;不论是以四倍体小麦还是六倍体小麦做母本, AB基因组染色体在F1自交过程中相对稳定, F2后代的数目均接近28条(27.9 vs. 28.0);以四倍体小麦为母本F2平均保留的D基因组染色体数显著多于以六倍体小麦为母本的后代(7.0 vs. 2.9)。因此,以四倍体小麦为最终目标后代时,应优先以六倍体小麦为母本进行杂交组合的配置;以六倍体小麦为最终目标后代时,应优先以四倍体小麦为母本开始最初的杂交组合配置。     

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。     

普通小麦与六倍体小黑麦杂交不亲和性的研究 Ⅰ.杂种的胚胎发育

本文对普通小麦与六倍体小黑麦这一组远缘杂交的不亲和性,从胚胎学的角度进行了研究。以六倍体小黑麦作母本,杂种胚胎发育与亲本的差异较小;以普通小麦作母本,杂种胚发育逐渐表现出显著的异常,最终是胚败育,种子失去生活力。通过对胚的切片的解剖观察和胚离体培养的研究,表明在以普通小麦作母本的杂交种子中,胚乳的发育异常发生在胚败育之前,及时将胚取出作离体培养可以发育成苗,因而证明胚的败育是由胚乳的异常发育引起的。本文讨论了这些杂交种子中胚乳发育的不同情况对胚的不同影响。     

冬、春小麦杂种F1及春小麦品系间杂种F1代主要农艺性状的研究

本文应用相关和通经系数分析方法，对两种杂交组合方式的小麦F1代农艺性状进行研究。结果表明，春小麦品种间杂交组合F1代的穗粒数多于春、冬小麦杂种F1代的穗粒数；两种杂交方式的F1代单穗粒数与单穗粒重的关系极为密切，对其单穗粒重的贡献最大。为春小麦优质高产育种提供科学途径。     

六倍体裸燕麦与普通小麦属间可交配性研究

以4个不同的六倍体裸燕麦品种和普通小麦进行正反杂交,确定裸燕麦和普通小麦的可交配性。调查杂种结实率并诱导杂种愈伤组织。结果表明：六倍体裸燕麦与普通小麦的可交配性和愈伤组织诱导率因品种和正反交方式的不同而不同。在以六倍体裸燕麦为母本的正交试验中,‘白燕2号’母本结实率最高,为12.98%。在以六倍体裸燕麦为父本的反交试验中,‘白燕5号’为父本时结实率最高,为6.25%。相同品种间正反交结实率也有差异。4个裸燕麦品种与春小麦的杂种胚均有较高的愈伤组织诱导率。此研究对燕麦的优异基因资源的利用和裸燕麦、小麦种质创新具有重要的理论和现实意义。     

人工合成六倍体小麦后代衍生群体Waxy蛋白亚基的分子标记

四倍体小麦与节节麦杂交培育的人工合成六倍体小麦已广泛应用于国内外小麦品种改良。以引自CIMMYT的Syn768、Syn769和Syn780人工合成六倍体小麦分别与中国四川成都平原主栽普通小麦品种杂交、回交的BC2F2:6后代群体中选育的113份优良高代系为材料,采用SSR特异引物的PAGE凝胶电泳对其Waxy蛋白亚基缺失类型进行了研究。结果表明,在所检测的121份材料中,8份材料缺失Waxy-B1型蛋白亚基,占全部材料的6.6%;没有检测到其他类型的缺失体。从每个人工合成六倍体小麦亲本材料所形成的后代衍生群体来看, Waxy-B1缺失体频率各不相同,说明Waxy蛋白亚基缺失类型在人工合成六倍体小麦后代衍生群体材料中的表现存在着随机性,与亲本的基因型状况关系极大。通过研究人工合成六倍体小麦与普通小麦杂交后代的Waxy蛋白亚基缺失类型,有助于提高分子标记育种效率。     

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。     

旱地杂种小麦优势测定及亲本组配模式研究

在旱作条件下,选用水旱两种生态型的小麦品种各4个,组成4×4不完全双列杂交,分折了8个主要农艺性状的超标优势和杂种优势,并对其遗传机制进行研究.结果表明水旱品种间杂交,其F1杂交优势普遍存在.F1杂种生态型是以千粒重为主,兼顾穗粒数,表现为重穗型.杂种F1产量性状变异受水地亲本影响大,旱地亲本对株高、穗下节长,单株穗数等与抗旱性密切的性状影响明显.水旱两种生态型品种杂交,易于实现抗旱与丰产的有机结合,是一种值得重视的抗旱育种杂交模式.     

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..     

棉花海陆杂交纤维品质性状遗传参数分析

为了研究棉花海陆杂交纤维品质性状的遗传规律,本试验采用5个陆地棉品种（系）作母本与5个海岛棉品种（系）杂交,配制25个杂交组合,随机区组试验设计,重复2次。主要检测杂交种F1代纤维品质性状,以小区平均数进行相应的方差分析及遗传参数估计。结果表明：陆地棉亲本间变异除马克隆值外,其他纤维品质性状均差异显著或极显著,而海岛棉亲本间除伸长率外,其他性状均存在显著或极显著差异;各纤维品质性状双亲互作效应均不显著。另外,遗传参数结果表明：绒长、比强度和马克隆值的遗传变异系数与表型变异系数变化趋势基本吻合,且均大于环境变异系数。整齐度和伸长率的遗传变异系数均小于环境变异系数,说明整齐度和伸长率的变异中环境因素的作用不容忽视。绒长、比强度和马克隆值的广义遗传率较高,在采用海陆杂交改良棉花纤维品质性状时,适宜在早代选择优异株系。     

Relationship of genetic distance and hybrid performance in hybrids derived from a new photoperiod-thermo sensitive male sterile wheat line 337S

Heterosis has been exploited in many crops and made a significant contribution to the world food supply. Genetic distance (GD) is one of valuable criteria for selecting parents in hybrid breeding. The objectives of this study were to estimate GD between a novel photoperiod-thermo sensitive male sterile wheat line 337S and several common cultivars using simple sequence repeat (SSR) markers, and to evaluate the relationship of GD and heterosis. The line 337S, as a maternal parent, was crossed with 16 common wheat varieties to produce 16 hybrids. Eight agronomic traits were investigated for the parents and F1 hybrids. Mid-parent heterosis (MPH) and specific combining ability (SCA) were calculated. GD and cluster analysis were performed among the 17 parents. The correlations of GD with F1 performance, MPH and SCA were analyzed. The results showed that GD estimates among the 17 parents averaged 0.42 with a range from 0.26 to 0.57, and the averaged GD between 337S and the 16 parental cultivars was 0.44. Cluster analysis separated the 17 parents into three main groups. SSR markers were useful in analyzing genetic divergences among the 17 parental lines. However, GD based on SSR markers poorly correlated with F1 performance, MPH and SCA. Thus, GD revealed by SSR markers can not provide a reliable prediction in practical wheat hybrid breeding.     

Regeneration potential of CIMMYT durum wheat and triticale varieties from immature embryos

Twenty‐five durum wheat elite advanced lines and released varieties, and five triticale varieties were evaluated for their ability to produce embryogenic callus using three different media. For callus initiation and maintenance there were basal Murashige and Skoog (MS) medium containing double strains of macroelements and 2.5 mg/l 2,4D (DW1), basal MS medium containing 2.0 mg/l 2,4D (DW2), or basal MS medium supplemented with 1.0 mg/l 2,4 D and coconut milk (DW3). Plant regeneration was achieved on basal MS medium with indoleacetic acid and 6‐benzylaminopurine, and plants rooted on MS with 1‐naphthale‐neacetic acid. DW3 medium proved better than the other media tested for embryogenic callus initiation and maintenance. Regeneration rates varied widely with both genotype and initiation medium, with values ranging from no regeneration to 100% regeneration; the plantlets produced per embryo ranged from five to 20. Fourteen of the durum wheat genotypes showed 63–100% regeneration from DW3 callus formation medium, four lines from DW1 medium, and two lines from DW2. Four of the triticale varieties had regeneration of 48–100% from DW3 medium. After six subcultures, over a 6‐month period, genotypes lost their ability to regenerate plants. Only 10 lines retained some plant regeneration potential but regeneration was at reduced levels. Successful regeneration of durum wheat and triticale varieties will be used as an integral part of the transformation process.     

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.     

小黑麦在连云港种植的越冬率及产量性状分析

为开发沿海滩涂的土壤资源,引进3个春性小黑麦品种东饲小黑麦1号、北联7号、新小黑麦5号在连云港种植。以当地冬小麦品种烟农王和烟农19为对照,评价了小黑麦的越冬性能与主要产量性状。试验结果表明,小黑麦的越冬率与当地冬小麦相似,未存在显著差异。在考察的主要农艺性状中,除有效分蘖数小黑麦与冬小麦间无显著差异外,其他各性状值小黑麦均显著或极显著地高于冬小麦,在连云港可以种植春性小黑麦。     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

A New Method to Produce 4× Triticales and their Application in Studying the Development of a New Polyploid Plant

F₁ hybrids of triticale × rye derived from commercial varieties were backcrossed to the respective triticale parent. Selfing of the backcross generation yielded a large number of 4× triticales containing a genetically balanced wheat genome. This indicates that the 28-chromosome F₁ plants with the genomic constitution of ABRR produced functional 14-chromosome gametes in high frequency each with a complete wheat and rye genome. The cytological mechanism leading to the formation of tetraploid triticales is described. The chromosomal constitution of the wheat genome in the progenies of 30 back cross plants was analysed by the C-banding technique. One offspring possessed a complete B genome of wheat. The production of tetraploid triticale through backcrossing in comparison to selfing the ABRR hybrid is largely independent of the genotype; it leads to new tetraploids in just three generations and it reduces the chance of translocations between the homoeologous wheat chromosomes. The possibility of studying the effect of different mixtures of chromosomes of the A and B genomes of wheat on the phenotype of the tetraploid triticale is discussed.     

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.     

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.