黑麦(Secale cereale)的染色体组型分析

本试验用涂片法制片,以低渗、酶解、火焰干燥以及分带等处理我国“甘肃黑麦”和加拿大黑麦“Kustro”的根尖细胞。从形态、C 带带型分析和比较了其染色体组型。两个品种无显著差异。其染色体的端粒带、核仁缢痕带都显著而较稳定。着丝点带也常出现。中间带变化较大。所有染色体分为三组:中部着丝点染色体;亚中部着丝点染色体;     

粗山羊草(Aegilops squarrosa)的染色体和同工酶分析

利用火焰干燥涂片法制片和吉姆沙染液分化染色,分析了粗山羊草的染色体组型和 C-带带型。粗山羊草具有7对染色体,包括5对中部着丝点染色体、1对亚中部着丝点染色体和1对随体染色体。除第1对染色体外,所有染色体都具着丝点带。有的染色体具变化较大的中间带和末端带。据聚丙烯酰胺凝胶电泳分析粗山羊草的酯酶和过氧化物酶同工酶,在幼苗不同时期,其酶谱是不同的。     

花生属拟直立型组野生种在栽培种改良中的应用——Ⅱ.染色体组型分析

本文分析了5个拟直立型组和2个花生组野生种的染色体组型:7个种皆为二倍体2n=2x=20,染色体长度介于2.69～6.47μm之间,臂比为1.07～2.54;在10对染色体中,8、9对具中部着丝点,其他具近中部着丝点。根据染色体长度、臂比及随体的位置,可把每个种(系)中6～10对染色体加以区分。研究中还把染色体的臂比作为独立性状,分析了供试种(系)间的遗传距离(D~2)。其中拟直立型组5个种(系)间的D~2差异很大(0.136～11.523),说明该组在进化过程中染色体组型已出现较大分化和变异。拟直立型组与花生组在染色体组型上虽有一定相似性,但差异更显著,首先,花生组中“A”“B”两个标志染色体在拟直立型组中不存在,其次是对称性优于拟直立型组。文中对上述两个组的进化程度作了进一步的讨论。     

野生一粒小麦(Triticum amyleum L)的染色体组型和带型研究

利用植物有丝分裂染色体标本制作的新方法进行野生一粒小麦根尖细胞染色体组型的分析,初步结果如下:其二倍体数为14个(2n=14),全部染色体可配成7对同源染色体,均为中部或亚中部着丝点染色体,根据其大小,形状和着丝点位置可分为三组。并没有发现任何一个染色体的长臂和短臂上带有随体。同时还用 Giemsa 分带技术进行了染色     

大兴安岭产胎生蜥蜴的染色体组型研究

本文采用骨髓细胞制片法,对分布在黑龙江省大兴安岭地区呼玛县的胎生蜥蜴(Lacerta vivipara)染色体组型进行了研究。结果表明,雄性胎生蜥蜴的二倍体染色体数是36,性染色体为ZZ型,2n=34+ZZ;雌性胎生蜥蜴的二倍体染色体数是35,性染色体为W型,2n=34+W,胎生蜥蜴的性别决定机制为ZZ/W型,其染色体全部为顶端着丝点染色体(除雌性的性染色体为中部着丝点染色体外)。     

药用植物知母染色体核型分析

目的：研究分析知母（Anemarrhena asphodeloides Bge.）染色体核型。方法：采用常规制片方法,并进行显微摄影。结果：知母细胞染色体数目2n=22;核型公式K(2n)=2x=22=16m+6sm。结论：11对染色体中8对为中部着丝点染色体(m),3对为近中部着丝点染色体(sm),未发现非整倍变异和多倍现象,核型不对称上属于为“2B”。     

节节麦与野燕麦8倍体杂种核型分析

节节麦(Aegilops tauschii(Coss.)Sch.2n=2x=14)与通北野燕麦(Avena fatua L.2n=6x=42)杂交,F_1自然加倍成8倍体,8倍体播成的F_2代,遗传性基本一致,PMC镜检表明,染色体数为2n=28Ⅱ。用F_2所结的种子进行根尖细胞核型分析,结果发现8倍体中包含有全套的节节麦和野燕麦的染色体。节节麦中有1对随体染色体.2对近中部着丝点染色体,4对中部着丝点染色体。野燕麦有3对随体染色体,5对近端着丝点染色体,8对近中部着丝点染色体,5对中部着丝点染色体。而节节麦与野燕麦8倍体杂种,有4对随体染色体,5对近端着丝点染色体.10对近中部着丝点染色体,9对中部着丝点染色体。核型分析结果表明,节节麦与野燕麦杂交合成的8倍体,是节节麦与野燕麦的双二倍体。     

葛氏鲈塘鳢（Perccottus glenii）的染色体组型研究

以葛氏鲈塘鳢（Perccottus glenii）的鳃、肾及肠细胞为材料,用空气干燥法制片,用Leica显微镜进行观察,依据Levan等（1964）的分类标准进行其染色体的数目及组型分析。结果表明葛氏鲈塘鳢的染色体数目为2n等于44条,n=22。染色体总臂数(NF)为82。其中,亚中部着丝点染色体为18对,亚端部着丝点染色体为1对,端部着丝点染色体为3对。核型公式为2n=36sm+2st+6t。根据染色体形态分析的结果,没有发现性染色体的存在。     

一粒小麦的染色体和同工酶分析

利用火焰干燥涂片法制备染色体玻片标本,观察到野生一粒小麦(T.boeo-ticum)和栽培一粒小麦(T.monococcum)的染色体组型基本相同。它们都具有着丝点带,但其中间带和末端带有些差别。在我们实验中它们的过氧化物同工酶及幼苗早期的酯酶同工酶酶谱也基本相似。因此野生一粒小麦和栽培一粒小麦可以归为一个一粒小麦种(T.monococcum),在小麦进化中,它们提供了 A 组染色体。     

玉米各亚种的核型研究

研究了玉米８个亚种，２个亚型的核型。所有材料的根尖细胞染色体数目均为２ｎ＝２０，主要由中部和近中部着丝点染色体组成，第６对染色体短臂均具随体。但臂比值不同，可区分为Ａ１（ｍ染色体）、Ａ２（ｓｍ）、Ａ３（ｓｔ）三类。在核型中具中部着丝点染色体的数目，罕见栽培或原始类型多于广泛栽培的类型。玉米各亚种的核型进化的趋势是由对称向不对称方向发展。     

Genetic control of crossability of triticale with rye

Limited genetic knowledge is available regarding crossability between hexaploid triticale (2n= 6x= 42, 21″, AABBRR, amphiploid Triticum turgidum L.‐Secale cereale L.) and rye (2n= 14, 7″, RR). Our objectives were to determine (1) the crossability between triticales and rye and (2) the inheritance of crossability between F₂ progeny from intertriticale crosses and rye. First, ‘8F/Corgo’, a hexaploid triticale, was crossed as a female with two landrace ryes, ‘Gimonde’ and, ‘Vila Pouca’ and two derived north European cultivars, ‘Pluto’ and ‘Breno’. These crosses produced 21.7, 20.9, 5.9, and 5.6%, seed‐set or crossability, respectively, showing that the landrace ryes produced higher seed‐set than the cultivars. Second, ‘Gimonde’ rye was crossed as a male with four triticales for 3 years. The control cross, ‘Chinese Spring’ wheat × rye, produced 80‐90% seed‐set. Of the four triticales, ‘Beagle’ produced 35.7‐56.8% seed‐set. The other three triticales produced less than 20% seed‐set, showing that the triticales differ in crossability with ‘Gimonde’ rye. Third, six FiS from intertriticale crosses (‘8F/Corgo’בBeagle’, ‘Beagle’בCachirulo’, ‘Lasko’בBeagle’, ‘8F/Corgo’בCachirulo’, ‘Lasko’בCachirulo’, ‘Lasko’ב8F/Corgo’) were crossed to ‘Gimonde’ rye. Results indicated that lower crossability trait was partially dominant in the two F₁S from crosses involving ‘Beagle’(high crossability) with‘8F/Corgo’ and ‘Cachirulo’(low crossability) and completely dominant in the ‘Beagle’בLasko’ cross, as it happens in wheat. Fourth, segregants in four F₂ populations (‘Lasko’בBeagle’, ‘8F/Corgo’בBeagle’, ‘Lasko’ב8F/Corgo’, and‘8F/Corgo’בCachirulo’) were crossed with rye. Segregation for crossability was observed, although distinct segregation classes were blurred by environmental and perhaps other factors, such as self‐incompatibility alleles in rye. Segregation patterns showed that ‘Beagle’, with high crossability to rye, carries either Kr1 or Kr2. The three triticales with low crossability with rye were most likely homozygous for Kr1 and Kr2. Therefore, it is likely that the Kr loci from A and B genomes acting in wheat also play a role in triticale × rye crosses.     

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.     

Fusarium head blight-resistant wheat line 'Bizel' does not contain rye chromatin

Fusarium head blight (FHB), primarily caused by Fusarium graminearum in North America can result in significant losses in the yield and quality of wheat (Triticum aestivum L). Resistance sources have been largely limited to Chinese germplasm and, in particular, Sumai 3 or its derivatives. In recent years, resistance has been identified in Europe. Previous studies using the wheat line ‘Bizel’, developed in France, have shown that it has resistance to Fusarium head blight. Pedigree information shows that one of its progenitors is rye. This experiment was conducted to determine if ‘Bizel’ has rye chromatin, with the goal of developing a strategy for mapping FHB resistance genes. Two methods based on repetitive DNA sequences specific to rye were implemented. With both approaches, it was demonstrated that ‘Bizel’ does not contain rye chromatin. Consequently, wheat SSRs can be used to map ‘Bizel’ resistance genes for FHB.     

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.     

Effect of D-Genome Chromosome Substitutions on Hybrid Seed Development and Viability in T. turgidum var. durum X S. cereale Crosses

Triticum turgidum var. durum cv. ‘Langdon’ and the set of D-genome disomicsubstitutions in ‘Langdon’, produced at Fargo, U.S.A., were grown in a temperature controlled greenhouse and crossed with diploid spring rye (Secale cereals), to determine the effect of each substitution on 1. the crossability with rye, and 2, the viability of the resulting hybrids kernels. None of the disomicsubstitutions lines, with the possible exception of the 5D (5Bj line, gave an appreciable improvement in hybrid kernel set, -development, and -viability over the control, ‘Langdon’ The post-zygotic barrier to endosperm and embryo development, which operates in crosses between durum wheat and rye, could therefore not be suppressed by any specific chromosome of the D-genome.     

Gene Localization of Aspartate Aminotransferase and Endopeptidase Isozymes in Wheat and Rye Using Developmental and Organ-Specific Patterns

Wheat, rye and wheat-rye addition lines have been investigated regarding their developmental and organ-specific isozyme patterns of aspartate amino-transferase (AAT) and endopeptidase (EP). Evidence is given, that development-specific isozymes of AAT are encoded by chromosomes 3R and 4R of ‘Imperial’ rye which can be used as biochemical markers up to leaf age of 14 days. Organ-specific increase of intensity of bands for AAT in stems could be assigned to genes or alleles of chromosome 3A of ‘Chinese Spring’ wheat. For EP new markers were localized on chromosomes 4R and 6R of ‘Imperial’ rye showing variability. Utilization of these markers is possible at all developmental stages of the leaves. Mechanisms of gene regulation are discussed.     

Confirmation of a 1A/1R Wheat-Rye Chromosome Translocation in the Wheat Variety 'Amigo'

Differential chromosome staining by using the Giemsa C- banding technique and test crosses have revealed rye chroma tin in the hexaploid wheat variety ‘Amigo’ which resulted from wheat crosses with the octoploid triticale ‘Gaucho’. The results demonstrated a pair of translocated wheat chromosomes involving the short arm of rye chromosome 1R and the long arm of the homoeologous wheat chromosome 1A (1Aq/1Rp translocation). The localization of the translocation breakpoint is supposed 10 be within the centromeric region.     

Genetical Studies of Gibberellic Acid Insensitivity in Rye (Secale cereale L.)

Genetic analysis of three semi-dwarf genotypes of rye (Secale cereale L.)—‘Moskowskij Karlik’, ‘Gülzow kurz’ and ‘R 18’, which were shown to be insensitive to applied gibberellic acid (GA₃), has been carried out by using a seedling test. It could be demonstrated that all of the three genotypes are carrying recessive alleles for GA-insensitivity. Whereas the alleles of ‘Moskowskij Karlik’ and ‘R 18’ seem to have the same locus on chromosome 5R, the GA-insensitivity of ‘Gülzow kurz’ is governed by a different gene, most probably located on chromosome 7R. The relationship between the genes (alleles) for GA-insensitivity and semi-dwarfness, including the symbolization of the Gai-genes as well as their utilization in rye breeding is discussed.     

Crosses Involving W. Rimpau's Triticale

One hundred years after the creation of the first true triticale crosses of Rimpau , several recent cultivars of triticale and rye have been crossed with two of them. Recombinants of the awned type of Rimpau 's triticale (10) with ‘Grado’, ‘Lasko’ and ‘Otello’ exhibited a prolonged vegetative period, a shorter straw, an improved lodging resistance, good yielding capacity and higher disease resistance as compared to ‘Lasko’.