Relationship between the grain pattern in the wood,domain pattern and pattern of growth activity in the storeyed cambium of trees

Summary The relationship between the arrangement of cell events occurring in cambium in a definite configuration and the grain pattern of wood was investigated. Taking into consideration the growth activity of fusiform cell ends, a model of a migrating morphogenetic wave determining an event configuration was made. Waves of length =1 m for the periods T=2 years and T=3 years and waves of lengths =l m and =0.04 m for the period T=10 years were considered. On the model, events from successive annual rings, conventionally comprising 10 cell layers each, were summed. In this way, event maps were obtained. For wave =4 mm, the domain pattern on the modelled map was compatible with the grain pattern. The domain pattern for the wave =1 m was impossible to recreate because the wave migrated too fast. In this case, the pattern of event configuration, incompatible with the grain pattern, formed microareas, which were not domains.     

A Cytogenetic Study of the Leaf Beetle Genus Cyrtonus (Coleoptera, Chrysomelidae)

The chromosomes of ten species of Cyrtonus and the genome sizes of six are surveyed. Among the total of 15 chromosomally studied species, 11 have 2n=28 chromosomes and a 13+Xy_p male meioformula, three have 2n=40 and 19+Xy_p and one 2n=46 and 22+Xy_p. All but one species with 28 chromosomes show only metacentric or submetacentric chromosomes, whereas the species with 40 and 46 chromosomes display some telocentrics or subtelocentrics, that are probably derived from the former by centric fissions. However, since the number of major chromosome arms is strikingly higher in these latter species (NF=70 and 78) than in the 28-chromosome species (mostly NF=56), other chromosomal rearrangements such as pericentric inversions or heterochromatin accretions could also be involved. The genome sizes display a narrow range, from 1C=0.6–1.22pg, and they are not significantly correlated with the chromosome numbers. Some possible factors implied in the rough chromosomal evolution of Cyrtonus are discussed in relation to a few other genera of the subfamily Chrysomelinae.     

In vitro culture of Aloe Barbadensis Mill.: Micropropagation from vegetative meristems

A method for rapid and highly effective plant micropropagation from vegetative meristems was established for Aloe barbadensis Mill. Plant micropropagation was achieved culturing apices on medium containing 1.1 M 2,4-dichlorophenoxyacetic acid and 2.3 M kinetin for 15–30 days. High morphogenetic ability was maintained by transferring explants (after 60 days) on media containing 0.11 M 2,4-dichlorophenoxyacetic acid and 2.2 M 6-benzylaminopurine.     

Effect of thidiazuron on vegetative tissue-derived somatic embryogenesis and flowering of bamboo Bambusa edulis

Current research on somatic embryogenesis of bamboo uses reproductive tissue as explants. However, it was hard to obtain the explant. Shoots of a local accession (3–4 m high) were used for multiple shoot production. In order to obtain embryogenic callus, nodal and internodal tissues from in vitro plantlets were placed on Murashige and Skoog (MS) medium supplemented with 9.2 M kinetin (KN), 13.6 M 2,4-dichlorophenoxyacetic acid (2,4-D), 0.1% (v/v) coconut milk, and 6% (w/v) sucrose. We studied the effects of sucrose and thidiazuron (TDZ) on callus proliferation. Optimal additives to the MS medium for embryogenic callus proliferation were 0.046 M TDZ, 13.6 M 2,4-D and 3% (w/v) sucrose. TDZ also promoted the germination of bamboo somatic embryos. The germination rate of the somatic embryos exceeded 80% on MS-based medium supplemented with 0.455M TDZ. Naphthaleneacetic acid (NAA) reduced germination. Well-developed plantlets were successfully transferred to soil. There was no albino mutant in subsequent culture. In vitro regenerants and potted plants flowered, but no seeds were produced.     

The spermatozoon of Oikopleura dioica Fol (Larvacea,Tunicata)

Summary The spermatozoon of Oikopleura dioica is about 30 m long, with a spherical head, about 1 m wide, a 3 m long and 1 m wide midpiece, and a 25 m long tail with a tapered end piece. The head contains a nucleus with the chromatin volume limited to about 0.1 m³. A small acrosome is found in an anterior inpocketing, and a flagellar basal body in a posterior inpocketing of the nucleus. The midpiece contains a single mitochondrion with the flagellar axoneme embedded in a groove along its medial surface. The flagellar axoneme has the typical 9 + 2 substructure, and the basal body the typical 9+0 substructure. A second centriole and special anchoring fibres are absent.     

Evolution of a protein superfamily: Relationships between vertebrate lens crystallins and microorganism dormancy proteins

Summary A search of sequence databases shows that spherulin 3a, an encystment-specific protein ofPhysarum polycephalum, is probably structurally related to the - and -crystallins, vertebrate ocular lens proteins, and to Protein S, a sporulation-specific protein ofMyxococcus xanthus. The - and -crystallins have two similar domains thought to have arisen by two successive gene duplication and fusion events. Molecular modeling confirms that spherulin 3a has all the characteristics required to adopt the tertiary structure of a single -crystallin domain. The structure of spherulin 3a thus illustrates an earlier stage in the evolution of this protein superfamily. The relationship of - and -crystallins to spherulin 3a and Protein S suggests that the lens proteins were derived from an ancestor with a role in stressresponse, perhaps a response to osmotic stress.     

Meiotic studies ofElymus nutans andE. jacquemontii (Poaceae,Triticeae) and their hybrids withPseudoroegneria spicata and seventeenElymus species

Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.     

Resistance to Spodoptera exigua in Apium prostratum

Two Apium accessions were compared with the commercial cultivar Tall Utah 52–70R (A. graveolens [L.]) for resistance to Spodoptera exigua (Hübner)(Lepidoptera: Noctuidae). Oviposition rate was not significantly different between the three genotypes. In all accessions, eggs were usually placed on the upper half of the plants. Implications of this oviposition pattern on S. exigua management in celery are discussed. The wild species A. prostratum ssp prostratum var filiform (A230) showed a significantly higher resistance to S. exigua than 52–70R. The levels of carcinogenic and mutagenic linear furanocoumarins in the commercial cultivar 52–70R (1.41 g/g in the petioles; 5.85 g/g in the leaves) and in the plant accession A. nodiflorum (5.40 g/g in the petioles; 2.99 g/g in the leaves) were far below the concentration reported to produce acute contact dermatitis (18.0 g/g). The levels of furanocoumarins in A. prostratum petioles (186.14 g/g) and leaves (326.45 g/g) were 10 and 18 times higher, respectively, than the concentration known to cause contact dermatitis. However, resistance in A. prostratum was primarily due to non-preference and the linear furanocoumarins did not induce non-preference. Therefore, the resistance shown by this plant accession does not appear to be furanocoumarin-based and may be suitable for transfer to commercial celery for use in S. exigua management.     

The effect of monoterpenes on astaxanthin production by a mutant ofPhaffia rhodozyma

Summary The total pigment and astaxanthin content ofPhaffia rhodozyma increased with increasing concentrations -pinene up to 500 l -pinene/l. Above this concentration the total pigment and astaxanthin content as well as the biomass production decreased. The addition of 500 l -pinene/l increased the total pigment content from 1652 g/g to 2201 g/g and the astaxanthin content from 1554 g/g to 1883 g/g. A sharp decrease in maximum specific growth rate occurred above 150 l -pinene/l.     

Kritische Betrachtungen zur Nomenklatur argentinischer Wildkartoffeln

Ohne ZusammenfassungDoch wer die Begeisterung nicht kennt wird zwar vor groben Fehlern, aber auch vor großen Leistungen bewahrt. (Der Philosoph W. Wundt an den Biologen E. Haeckel.Mit 2 Textabbildungen     

Sisal plant regeneration via organogenesis

Callus was initiated from in vitro grown immature leaf and ex vitro grown mature leaf and rhizome explants of Agave sisalana Perr. ex. Engelm, on MS medium containing 2,4-D (9.05 M) and kinetin (4.6 M) or 2,4-D (9.05 M), kinetin (4.6 M) and CH (1000 mg l^–1) or mod. MS (NH₄NO₃, 1500 mg l^–1) containing 2,4-D (9.05 M) and kinetin (4.6 M). Light was essential for callus formation which, however, was different in three types of explants on three different media compositions. Increasing NH₄ ⁺had a negative impact while addition of CH had a positive impact on callus formation. Shoot regeneration from callus from CH-supplemented medium only was achieved for rhizome and immature leaf tissues. The highest rate of regeneration was obtained with BA (26.6 M) as the sole hormone. Shoot buds g^–1 callus varied according to BA concentrations. Shoot proliferation rate increased on half-strength MS medium containing BA (8.9 M). Microshoots developed on MS medium containing BA (2.22 M) and GA₃ (1.44 M) and finally rooted on MS medium containing IAA (11.42 M). Acclimatized rooted plantlets are growing satisfactorily in ex vitro. This is the first report on plant regeneration via organogenesis of A. sisalana.     

Effects of constant and fluctuating temperatures on sporulation and infection by the aphid-pathogenic fungus Pandora neoaphidis

Laboratory studies were performed to assess the importance of temperature on sporulation and infection by the aphid-pathogenic fungus Pandora neoaphidis (Remaudière and Hennebert) Humber. Numbers of primary conidia discharged from mycelium formulated as alginate granules and unformulated mycelial mats were assessed, as well as infection of the potato aphid, Macrosiphum euphorbiae (Thomas) (Homoptera, Hemiptera, Aphididae), using culture plugs as inoculum sources. Sporulation from experiments at constant temperatures indicated the optimum temperature range was 10–20°C for both mycelial preparations and there was no or very little sporulation at 30°C. Infection of aphids kept at 15°C was 34–50%, while infection at 25°C was 11–44%. At 20°C, 77–79% of aphids were infected. Under fluctuating temperature cycles, conidia numbers did not differ when mycelial preparations were maintained at 18–25°C compared with 18–20°C, but fewer conidia were recorded when preparations were exposed continuously to 18–30°C. Infections of inoculated aphids kept for varying numbers of days at 18–25°C varied between 24–47%, but only 3–32% of aphids were infected when exposed to a cycle of 18–30°C for various times. Unformulated mycelial mats of P. neoaphidis appear to be superior to forumlated alginate granules for use in experimental greenhouse and field trials, since temperature stability is similar for both materials but mycelial mats are much easier to produce.     

Changes in density of chromatin in the meristematic cells ofSinapis alba during transition to flowering

Summary Changes in the density of nuclear chromatin in the shoot apical meristem ofSinapis alba L. during floral transition (floral evocation) are described using Feulgen-stained 2 m thick semi-thin sections and scanning cytophotometric techniques. In both G1 and G2 nuclei the chromatin becomes less heterogeneous and less dense in evoked meristems compared to vegetative meristems. When chromatin is resolved into two fractions the dispersed fraction increases relative to the condensed fraction at evocation. This decondensation process occurs earlier in G1 than in G 2 nuclei. These chromatin changes are presumably closely related to the dramatic stimulation of biosynthetic activity and cell division during floral transition.     

Molecular mapping of a new gene Rrs4 CI 11549 for resistance to barley scald (Rhynchosporium secalis)

Doubled haploid (DH) progeny from a cross between the scald susceptible barley (Hordeum vulgare L.) cultivar Ingrid and the resistant accession CI 11549 (Nigrinudum) was evaluated for resistance in the pathogen Rhynchosporium secalis (Oudem) J.J. Davis. Two linked and incompletely dominant loci confer resistance CI 11549 against isolate 4004. One is an allele at the complex Rrs1 locus on chromosome 3H close to the centromere; the other is located 22 cM distally on the long arm. The latter locus is designated Rrs4. In BC₃-lines into Ingrid from CI 2222 (another Nigrinudum) resistance seems governed by one locus close to the telomeric region of chromosome 7H, probably allelic to Rrs2. In neither case did we find any trace of the recessive gene rh8 reported to be present in Nigrinudum. Various resistance donors of Ethiopian origin designated as Nigrinudum, Jet or Abyssinian were identical to a great extent with respect to markers, but differed in resistance to different isolates of scald or in barley yellow dwarf virus (BYDV) resistance. The implications for their use as differentials in scald tests and screening of germplasm collections are discussed.     

Primary structure of the marmoset (Saguinus fuscicollis) hemoglobin. I. Use of tryptic maleylated peptides in the solubilization and sequence elucidation of the α- and β-chains

The primary structure of adult marmoset hemoglobin has been determined. The - and -chains of HbA were separated on a CM23 column in 8 M urea using a sodium phosphate gradient. Tryptic digests of the - and -chains were fractionated on a Dowex 50W-X2 column using a pH and pyridine acetate gradient. Large peptide fragments were obtained by the cyanogen bromide cleavage of the - and -chains, as well as by tryptic digestion of the maleylated - and -chains. The sequence was derived from the amino acid compositions and sequences of the individual tryptic peptide, automated sequence determination of intact - and -chains, as well as automated sequence determination of cyanogen bromide fragments and tryptic maleylated peptides derived from the - and -chains. The complete structure of marmoset adult hemoglobin is closely homologous to that of other primate hemoglobins. The sequence of the marmoset -chain differs from the -chain of human HbA at positions 8, 19, 23, 68, and 116. The -chain from marmoset HbA differs from the -chain of human HbA at positions 5, 13, 21, 50, 87, and 125.This work was supported in part by funds from a Physicians' Medical Education and Research Foundation Grant of the University of Tennessee Memorial Research Hospital and by NIH General Research Support Grant FR-5541 to the institution.     

Nuclear Overhauser effect investigation on GM1 ganglioside containingN-glycolyl-neuraminic acid (II3Neu5GcGgOse4Cer)

The conformational properties of the oligosaccharide chain of GM1 ganglioside containingN-glycolyl-neuraminic acid, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer, were studied through NMR nuclear Overhauser effect investigations on the monomeric ganglioside in dimethylsulfoxide, and on mixed micelles of ganglioside and dodecylphosphocholine in water. Several interresidual contacts for the trisaccharide core--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-were found to fix the relative orientitation of the three saccharides, while the glycosidic linkage of the terminal -Gal-was found to be quite mobile as the -Gal-(1-3)--GalNAc-disaccharide exists in different conformations. These results are similar to those found for two GM1 gangliosides containingN-acetyl-neuraminic acid and neuraminic acid [1].Abbreviations Ganglioside nomenclature is in accordance with Svennerholm [23] and the IUPAC-IUB Recommendations [24] GM3(Neu5Ac) II³Neu5AcLacCer, -Neu5Ac-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM3(Neu5Gc) II³Neu5GcLacCer, -Neu5Gc-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Ac) II³Neu5AcGgOse₄Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu5Gc) II³Neu5GcGgOse₄Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GM1(Neu) II³NeuGgOse₄Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu-(2-3)]--Glc-(1-1)-Cer - GD1a IV³Neu5AcII³Neu5AcGgOse₄Cer, -Neu5Ac-(2-3)--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - GalNAc-GD1a IV⁴GalNAcIV³Neu5AcII³Neu5AcGgOse₄Cer, -GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer - Neu neuraminic acid - Neu5Ac N-acetyl-neuraminic acid - Neu5Gc N-glycolyl-neuraminic acid - Cer ceramide     

In vitro shoot regeneration from leaf explants of Roman Chamomile

Murashige and Skoog (1962) medium supplemented with 1.0 to 4.5 M of BA and 1.0 M of NAA induced adventitious bud formation and shoot development in leaf explants of Roman Chamomile. A higher number of adventitious buds was observed at the proximal end of the explants. Plantlets were replicated and multiplied on MS medium supplemented with 2.25 M of BA and 0.6 M of IAA. Plantlets were rooted on MS medium supplemented with 0.5 M of IBA and successfully weaned in vivo. The plants grew to maturity with high uniformity and no morphological signs of somaclonal variation.     

Fine structure of early previtellogenic oocytes in Mugil (Liza) auratus Risso, 1810 (Teleostei,Mugilidae)

Summary Sequential cytological events at the onset of previtellogenesis were studied in oocytes from 12 m to 70 m in diameter of golden grey mullet. The main cytological changes observed (increase in size of cell, nucleus, nucleolus and increase in number of nucleoli, RNP particles, nuage and mitochondria) provide evidence for important synthetic processes in an early preparatory phase of oocyte development.Somatic cells (pre-follicle, follicle and thecal) are also described.     

Effects of cycloheximide on preprophase bands and prophase spindles in onion (Allium cepa L.) root tip cells

Summary Effects of cycloheximide (CHM) on preprophase bands (PPBs) of microtubules (MTs) and on prophase spindle MTs in root tip cells of onion (Allium cepa L.) were examined. When root tip cells were treated with 36 M CHM for 0.5–4 h, the population of cells with a PPB did not decrease markedly although the population of mitotic cells and that of prophase cells with a PPB gradually decreased to half of the control root tips. In prophase cells treated with 11 and 36 M CHM for 2 h, the width of the PPB was 1.4 times broader than that in the prophase PPB without CHM. Electron microscopic observation on the cross section of the PPB showed that the number of MTs and the distance between adjacent MTs in prophase PPBs treated with CHM were similar to those in the early developmental stage of PPBs without CHM. The bipolar spindle, that appeared in late prophase was not seen in prophase cells treated with 11 M or higher concentrations of CHM for 2 h. In order to examine differences of perinuclear MT arrangement between CHM treated and non-treated prophase cells, arrangement of perinuclear MTs was examined by confocal laser scanning microscopy. In control cells without CHM, MTs appeared on the nuclear surface with several branched or cross over type MT foci in the cytoplasm when broad PPB formation started. These MT foci were replaced by the aster type MT foci, from which several MTs radiated along the nuclear surface. The aster type MT foci gradually gathered to form a bipolar spindle. MTs connecting the spindle pole region and the PPB were seen in late prophase. In CHM-treated cells (11-360 M for 2 h), branched and cross over type MT foci were prominent, even in prophase cells with well condensed chromosomes. Neither linkages of MTs between the spindle pole region and the PPB nor aster type MT foci were seen. These observations showed that CHM prevents the bundling of MTs in the PPB and also inhibits the formation of aster type MT foci that is essential for bipolar spindle development.     

Solution conformations of proline rings in proteins studied by NMR spectroscopy

Summary Three different conformations of proline rings in a protein in solution, Up, Down and Twist, have been distinguished, and stereospecific assignments of the pyrrolidine -, - and -hydrogens have been made on the basis of ¹H-¹H vicinal coupling constant patterns and intraresidue NOEs. For all three conformations, interhydrogen distances in the pairs -³, ³-³, ²-², ²-², and ³-³ (2.3 Å) are shorter than those in the pairs -², ²-³, ³-², ²-³, and ³-² (2.7–3.0 Å), resulting in stronger NOESY cross peaks. For the Up conformation, the ³-² and ²-³ spin-spin coupling constants are small (<3 Hz), and weak cross peaks are obtained in a short-mixing-time (10 ms) TOCSY spectrum; all other vicinal coupling constants are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. For the Down form, the -², ²-³, and ³-² vicinal coupling constants are small, leading to weak TOCSY cross peaks; all other couplings again are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. In the case of a Twist conformation, dynamically averaged coupling constants are anticipated. The procedure has been applied to bovine pancreatic trypsin inhibitor and Cucurbita maxima trypsin inhibitor-V, and ring conformations of all prolines in the two proteins have been determined.