Satellited chromosomes,systematics and phylogeny inTaraxacum (Asteraceae)

A survey is made of the occurrence, nature and frequency of satellited chromosomes in the agamospermous genusTaraxacum. Species belonging to the 10 sections thought to be most primitive in the genus lack satellited chromosomes. In most other sections, a characteristic satellited chromosome is seen with a large euchromatic region distal to the presumed nucleolar oraniser region (NOR). In sections of a precursor type, there is always one chromosome of this Taraxacum type per haploid genome. In sections thought to be of an advanced type the number of such satellited chromosomes is very unstable, sometimes even within the same tissue. In sectionHamata, two such satellited chromosomes are invariably found in triploids. This finding strongly supports the integrity of this section, suggests that the species of the section are monophyletic, and have evolved from a single ancestor subsequent to the occurrence of obligate agamospermy. In three sections of the genus, satellited chromosomes of the conventional type with a very small distal euchromatic region distal to the NOR are reported for the first time in the genus.     

Fractionation of wheat gliadin and glutenin subunits by two-dimensional electrophoresis and the role of group 6 and group 2 chromosomes in gliadin synthesis

Summary Subunits of wheat endosperm proteins have been fractionated by two-dimensional electrophoresis. To determine which subunits in the two-dimensional electrophoretic pattern belong to gliadin or glutenin the endosperm proteins have also been fractionated by a modified Osborne procedure and by gel filtration on Sephadex G-100 and Sepharose CL-4B prior to separation by two-dimensional electrophoresis.The control of production of five major grain protein subunits is shown to be determined by chromosomes 6A, 6B and 6D by comparing two-dimensional electrophoretic protein subunit patterns of aneuploid lines of the variety Chinese Spring. From these and previous studies it is concluded that some , and gliadins (molecular weights by SDS-PAGE 30,000 to 40,000) are specified by genes on the short arms of homoeologous Group 6 chromosomes, the gliadins (molecular weights by SDS-PAGE 50,000 to 70,000) are specified by genes on the short arms of homoeologous Group 1 chromosomes and the glutenin subunits (molecular weights by SDS-PAGE > 85,000) are specified by genes on the long arms of homoeologous Group 1 chromosomes.No major gliadins or glutenin subunits were absent when any of the chromosomes in homoeologous Groups 2, 3, 4, 5 or 7 were deleted. However two gliadins whose presumed structural genes are on chromosome 6D were absent in aneuploid stocks of Chinese Spring carrying two additional doses of chromosome 2A. Two out of thirty-three intervarietal or interspecific chromosome substitution lines examined, involving homoeologous Group 2 chromosomes, lacked the same two gliadins. All the subunits in the other thirty-one chromosome substitution lines were indistinguishable from those in Chinese Spring. It is therefore concluded that the major variation affecting gliadin and glutenins in wheat is concentrated on the chromosomes of homoeologous Groups 1 and 6 but Group 2 chromosomes are candidates for further study.An endosperm protein controlled by chromosome 4D in Chinese Spring is shown to be a high molecular weight globulin.     

Analysis of the effect of rye chromosomes 4R, 6R and telomeric heterochromatin on 7R on homologous chromosome pairing in pentaploid hybrids (AABBR,AABBD)

Summary Meiotic pairing in Triticum turgidum cv. Ma (4x) with a mean chiasmata frequency of 27.16 per cell was compared with chiasmata frequencies in its hybrids with several triticale strains, Chinese Spring wheat and its addition lines for Imperial rye chromosomes 4R and 6R. In hybrids between Ma and x Triticosecale cv. Rosner the chiasmata frequency was marginally reduced by an average of 1.25%, by 8.8% in hybrids with x Triticosecale cv. DRIRA HH and by 6.7% with DRIRA EE (lacking 90% telomeric heterochromatin from chromosome arm 7RL). In pentaploid hybrids between Ma and T. aestivum cv. Chinese Spring the reduction was an average of 10.30%, while addition lines with rye chromosome 6R reduced chiasmata frequencies by an average of 7.4% and rye addition line for 4R showed the greatest depression in chiasmata frequency in hybrids by a 25.04% reduction. An interchange difference involving long chromosome segments was observed between Ma and Rosner.Contribution No. 819 Ottawa Research Station     

Heritable variation in the phaseolin protein of nondomesticated common bean,Phaseolus vulgaris L.

Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F₂ progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly.     

Production of multiple wheat-rye 1RS translocation stocks and genetic analysis of LMW subunits of glutenin and gliadins in wheats using these stocks

Summary A triple (1AL.1RS/1BL.1RS/1DL.1RS) and three double (1AL.1RS/1BL.1RS, 1AL.1RS/1DL.1RS, 1BL.1RS/1DL.1RS) wheat-rye 1RS translocation stocks were isolated from a segregating population using the Gli-1, Tri-1 and Sec-1 seed proteins as genetic markers. These stocks carried 42 chromosomes and formed the expected multivalents (frequency of 14–25%) at metaphase 1. They gave floret fertility ranging from 40–60%. These stocks were subsequently used to determine the genetic control of low-molecular-weight (LMW) glutenin subunits in Chinese Spring and Gabo by means of two-step one-dimensional SDS-PAGE. All of the B subunits and most of the C subunits of glutenin were shown to be controlled by genes on the short arms of group-1 chromosomes in these wheats. The other C subunits were not controlled by group-1 chromosomes. The triple translocation line served as a suitable third parent in producing test-cross seeds for studying the inheritance of the LMW glutenin subunits and gliadins in wheat cultivars, e.g. Chinese Spring and Orca. The segregation patterns of the LMW glutenin subunits in these cultivars revealed that the subunits were inherited in clusters and that their controlling genes (Glu-3) were tightly linked with those controlling gliadins (Gli-1). The LMW glutenin patterns d, d and e in Orca segregated as alternatives to the patterns a, a and a in Chinese Spring controlled by Glu-A3, Glu-B3 and Glu-D3 loci on chromosome arms 1AS, 1BS and 1DS, respectively, thus indicating that these patterns were controlled by allelic genes at these loci.     

A simple method for maintaining high multiplication of Narcissus shoot cultures in vitro

A simple method for stimulating and maintaining high in vitro multiplication of Narcissus shoot clump cultures was developed. Shoot clumps were subjected either to normal cutting where leaves were trimmed to 20 mm in length at the beginning of each culture passage or to severe cutting where shoot clumps were cut down to the basal plate region removing all green tissue. Severe cutting at the beginning of each culture passage initially doubled the leaf multiplication, compared to normal cutting, but the difference between cutting treatments declined in successive passages. The improvement in leaf multiplication was maintained when shoot clumps were subjected to severe cutting only at every other culture passage, with no cutting in the alternate recovery passages. In vitro multiplication was increased by severe cutting in all seven Narcissus cultivars which were tested.Abbreviations NAA-1 naphthylacetic acid - BAP benzylaminopurine     

Soybean seedling emergence at high temperatures

Bragg and Cobb soybean [Glycine max (L.) Merr.] seeds were germinated in sand at temperatures ranging from 25 to 40°C. Emergence decreased with increasing temperature above 37°C, with virtually no emergence at 40°C. Emergence of 12 other cultivars at 38°C ranged from 25 to 95%. Foster and Coker 338 were more sensitive to high temperature than the other cultivars.     

Esterase isozymes in rye — characterization,genetic control and chromosomal location

Summary The zymogram phenotypes that Chinese Spring-Imperial, Holdfast-King II and Kharkov-Dakold wheat-rye addition lines presented for esterase isozymes were determined using polyacrylamide gel ectrophoresis. The analyses were carried out with different parts of the dry kernel, namely embryo plus scutellum and endosperm, leaves and roots. In all cases, embryo plus scutellum, endosperm and leaf presented different patterns of esterases. The patterns of leaves and roots were the same. Results indicate that rye esterases exist as monomers and dimers. Dimeric esterases are controlled by one locus located on the 3R chromosomes of Imperial, King II and Dakold rye cultivars. Five loci involved in the production of monomeric esterases have been located on the 6R chromosomes of these cultivars, specifically on the long arm of the King II 6R chromosome. On the basis of these results, considerations concerning chromosome homoeology and homology are made.     

The meiotic pairing of nine wheat chromosomes

Summary The meiotic identification of nine pairs of chromosomes at metaphase I of meiosis of Triticum aestivum (B genome, 4A and 7A) has been achieved using a Giemsa C-banding technique. As a result, the analysis of the pairing of each chromosome arm in disomic and monosomic intervarietal hybrids between Chinese Spring and the Spanish cultivar Pané 247 could be carried out. Differences in the chiasmata frequencies per chromosome arm cannot be explained on the basis of relative arm lengths only. Possible effects of arm-to-arm heterochromatic differences on meiotic pairing are discussed.     

Ultrastructural localization of ‘anixiopsin’: a lectin of the fungus Anixiopsis stercoraria (Hansen) Hansen

In order to localize the anixiopsin, a lectin of the keratinolytic fungus Anixiopsis stercoraria, the authors used a monospecific antiserum prepared by immunization of rabbits with their own erythrocytes coated in vitro with anixiopsin. In light and scanning electron microscopies, lectinic sites were visualized by means of latex microspheres sensitized with anti-rabbit IgG antibodies. In transmission electron microscopy using the IgG fraction of the rabbit anti-anixiopsin immune sera and protein A-gold, anixiopsin seemed mainly present on the outermost cell wall layer of the ascospores, in a pseudomembraneous structure dense to electrons. Implications of these results on physical and biological properties of the lectin are discussed.     

The addition of Dasypyrum villosum (L.) Candargy chromosomes to durum wheat (Triticum durum Desf.)

Summary Six monosomic addition lines were produced in which different Dasypyrum villosum (L.) Candargy chromosomes were added to the chromosome complement of Triticum durum Desf. cv. Creso. Each added alien chromosome was found to have a specific effect on plant morphology and fertility. Transmission rate varied widely (from 7.5 to 27.7%) among the six univalent chromosomes. Different monotelosomic addition plants derived by a relatively high frequency of chromosome misdivision were isolated. The addition lines should be useful for studying Dasypyrum chromosome homoeology and the introduction of alien variation into durum and common wheats.Research supported by a grant from the Italian Research Council for Finalized Project IPRA. Sub-project Plant Breeding, Paper No. 1095     

The chromosomal location of factors determining the presence of phenolic compounds in wheat (Triticum aestivum L.)

Summary Using thin-layer chromatography and nulli-tetrasomic and ditellosomic series of Triticum aestivum L. cv. Chinese Spring, it has been possible to relate the phenolic compounds found in adult plant leaves and 12 day-old seedling leaves with the chromosomes or chromosome arms 1 B, 2 BL, 3 BL, 5 A, 6 AL, 7 B and 7 DS.     

Genetic linkage maps of two apple cultivars (<Emphasis Type="Italic">Malus</Emphasis> × <Emphasis Type="Italic">domestica</Emphasis> Borkh.) based on AFLP and microsatellite markers

Genetic linkage maps for two apple cultivars were constructed using AFLP and SSR markers and the pseudo-testcross mapping strategy. The F₁-mapping population was produced by crossing the cultivar Braeburn to the cultivar Telamon and consisted of 257 individuals. Out of the 182 AFLP primer combinations screened, a total of 48 were selected. Using these, 463 AFLP markers segregating 1:1 in the progeny were identified, of which 231 were heterozygous in Telamon and 232 in Braeburn. Eighty-five AFLP markers present in both cultivars (3:1 segregation) were scored in the whole mapping population. Twenty-one SSR primer pairs were tested, which clearly screened 23 loci (some multi-locus markers). This resulted in the identification of 3 loci heterozygous only in Telamon (1:2:1), 5 loci heterozygous only in Braeburn (1:2:1) and 15 loci which were heterozygous in both cultivars (1:1:1:1). Two linkage maps were produced. The Telamon map comprised 259 markers (242 AFLPs and 17 SSRs) divided into 17 linkage groups. The total map length was 1039 cM with a marker density of 4.0 cM. At = 0.05, 8.9% of the mapped loci showed distorted segregation. The Braeburn map consisted of 264 markers (245 AFLPs and 19 SSRs) mapped on 17 linkage groups and spanning 1245 cM. The average distance between two markers was 4.7 cM and segregation distortion was observed for 18.6% of the mapped markers ( = 0.05). Fourty-six markers common to both maps (32 AFLPs and 14 SSRs) allowed the identification of 16 homologous linkage groups. The seventeenth pair of homologous linkage groups from Telamon and Braeburn was identified by 2 SSR markers which were in common to the genetic linkage maps of Fiesta and Discovery, two other apple cultivars.     

Genetic analysis of resistance to whitebacked planthopper in twenty-one varieties of rice,Oryza sativa L.

Summary The inheritance of resistance to whitebacked planthopper Sogatella furcifera (Horvath) was studied in 21 rice varieties. Reactions of F₁; F₂ and F₃ progenies of the crosses of 21 resistant varieties with the susceptible variety TN 1 revealed that a single dominant gene governs resistance in Mushkan 41, Santhi, Siahnakidar 195, SM2-34, Tirisurkh 251, Zirijowaian 245, 18, 24A, 39, 76 S, 78, 180, 213 B, 267, 293, CI 6037-4, NP97, S39 JKW and Bansphul. In varieties 65 and 274 A, resistance is governed by one dominant and one recessive gene which segregate independently of each other. Tests for allelism with the Wbph 1 gene originally identified in N 22 revealed that the dominant gene present in all the test varieties is the same as Wbph 1. Further studies are required to determine the allelic relationships of the recessive gene found in varieties 65 and 274 A.     

Comparative study ofTriticum aestivum andT. timopheevi genomes using C-banding technique

The somatic chromosomes ofTriticum timopheevi and those of two varieties ofT. aestivum, Chinese Spring and Bezostaya-1, have been identified by a Giemsa staining technique. The data suggest thatT. timopheevi and tetraploid wheats had a common ancestor from which their genomes differentiated due to chromosomal aberrations and the increase of heterochromatin in the chromosomes of theT. timopheevi G-genome. The differences between the chromosomes of the AB and AG genomes result in substitutions and large translocations between these chromosomes in interspecific hybrids.     

Identification of C-banded chromosomes in meiosis of common wheat,Triticum aestivum L.

Summary The C-banding pattern of nine meiotic chromosomes of common wheat (Triticum aestivum L.) as described. In F₁s of crosses between monosomics of Chinese Spring and two Spanish wheat cultivars, univalent chromosomes were used to aid the recognition and analysis of the C-banding pattern for the individual chromosomes. The identification of one chromosome involved in one translocation in Chinese Spring x Pané 247 has been made through heterochromatin bands observed in the chromosomes involved in multivalents.     

A 500-MHz1H-NMR study on theN-linked carbohydrate chain of bromelain

The 500-MHz¹H-NMR characteristics of theN-linked carbohydrate chain Man1-6[Xyl1-2]Man1-4GlcNAc1-4[Fuc1-3]GlcNAc1-NAsn of the proteolytic enzyme bromelain (EC 3.4.22.4) from pineapple stem were determined for the oligosaccharide-alditol and the glycopeptide, obtained by hydrazinolysis and Pronase digestion, respectively. The¹H-NMR structural-reporter-groups of the (1–3)-linked fucose residue form unique sets of data for the alditol as well as for the glycopeptide.     

Expression of the β-subunit of β-conglycinin in seeds of transgenic plants

Soybean (Glycine max (L.) Merr.) seeds contain the storage protein -conglycinin, encoded by a multigene family. -Conglycinin consists of three subunits; , , and . A genomic clone for a -subunit of -conglycinin has been characterized by restriction-enzyme mapping and hybrid selected in-vitro translation followed by immunoprecipitation. In order to determine the developmental regulation of this -subunit gene, its expression was studied in seeds of transgenic petunia (Petunia hybrida) and tobacco (Nicotiana tabacum L.) plants. The -subunit expressed in seeds of petunia and tobacco was recognized by anti--conglycinin serum at a relative molecular mass of 53 000, equivalent to that of the native protein. Separation of the petunia-seed proteins by isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis showed that multiple isoelectric forms of the -subunit were produced. There was approximately a twofold variation in the accumulation of the -subunit protein in the mature seeds of transgenic petunia plants, each containing a single -subunit gene. However, the level of protein accumulation in mature seeds and the amount of -subunit mRNA in developing seeds was not correlated. Accumulation of the -subunit protein in transgenic seeds was less than the -subunit protein that accumulated in transgenic petunia seeds containing a single -subunit gene and less than the amount of the -subunit in mature soybean seeds which contain 8–13 -subunit genes. In transgenic tobacco plants, the accumulation of the -subunit protein in seeds was generally well correlated with the number of genes that were incorporated in the different transformants.Abbreviations kb kilobase - kDa kilodalton - M_r relative molecular mass - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis     

Genotypic control of pollen plant formation in Nicotiana tabacum L.

Summary Tobacco plants (Nicotiana tabacum L.) of four varieties (Badischer Burley, White Burley, Techne, Kupchunos) were raised at different temperatures and daylengths and the effect of genotype on embryogenic pollen grain formation in situ and on pollen plant formation in anther and pollen cultures from these plants was studied. Genotype controlled embryogenic pollen grain and pollen plant formation by defining productivity under standard growth conditions (long days at 24 °C). Kupchunos was the most productive variety, followed by White Burley, Techne, and Badischer Burley. Furthermore, genotype defined which environmental factor was able to affect embryogenic pollen grain and pollen plant formation and also to which degree. In anther cultures, in addition to these effects, genotype controlled the formation of (an) inhibitory substance(s) in the anther wall in interaction with the plant growth conditions. In Badischer Burley and Techne, inhibitor action could be prevented by isolation of the pollen after one week of anther culture. Finally, direct pollen cultures in Badischer Burley and Techne produced embryos were only when the pollen was isolated from nearly mature anthers, while in White Burley and Kupchunos, embryos also produced at earlier stages and at higher yields. This indicated that genotype controls the time when the embryogenic pollen grains become ready to divide. The results are discussed in relation to strategies to overcome recalcitrance of species and genotypes.     

Cytogenetic analysis of structural rearrangements in three varieties of common wheat,Triticum aestivum

Summary The winter wheat varieties Starke and Cappelle Desprez and the spring wheat Chinese Spring were analysed for structural chromosome rearrangements that resulted in the formation of multivalents in F₁ hybrids. The analyses were carried out using hybrids involving euploids, monosomic and ditelosomic stocks, and double-monotelodisomic constructs. The study confirmed that Cappelle Desprez differs from Chinese Spring in a reciprocal translocation between chromosomes 5B and 7B (Riley et al. 1967); a translocation involving chromosomes 3B and 3D could not be verified. Furthermore, the analysis showed that Starke differs from Chinese Spring in a reciprocal translocation between chromosomes 7A and 7D. Both translocations have a coefficient of multivalent realisation of about 0.84. Further multivalents in euploid Starke, in euploid and some aneuploid stocks of Cappelle Desprez, and in euploid as well as various types of aneuploid hybrids between all three varieties could nearly all be explained hypothesizing that chromosome 2B of both Starke and Cappelle Desprez is a duplication-deficiency chromosome. In the hypothesis a part of the long arm of 2B is missing and replaced by a duplicated part of the long arm of chromosome 2D. The multivalents of this rearrangement showed an average coefficient of realisation of about 0.09.Sven Ellerström died in December 1985