Temperature-related non-homogeneous fatty acid desaturation in sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) seeds

The fatty acid compositions of half-seeds and whole seeds of the temperature-dependent high-stearic-acid sunflower (Helianthus annuus L.) mutant CAS-14 were unexpectedly different. We found that there is a longitudinal gradient starting from the embryo up to the end of the cotyledon. The stearic acid content varied from 9.7 to 34.6% in seeds produced in a growth chamber (39/24 degrees C; day/night), and from 14.0 to 34.4% in seeds produced in the field during the summer season (35-40 degrees C in daylight and 20-25 degrees C at night). The gradient occurs throughout seed formation, and is due to a spatial and non-temporal regulation of stearic acid desaturation. A similar temperature-regulated behaviour, but for oleic and linoleic acid contents, was found in normal sunflower seeds. Since the deposition of oil bodies was homogeneous during seed formation, seeds showed the gradient throughout their development. This non-homogeneous distribution must be due to differences in the enzymatic pathway of de-novo fatty acid desaturation along the seed, resembling a morphogen gradient. Other high-stearic-acid mutant lines, such as CAS-3, did not show any gradient. This is the first time that a gradient and an inheritable maternal control of the fatty acid composition have been found in oilseeds.     

In vitro culture of isolated living sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) embryo sacs

Ovules of sunflower tubular florets were observed histologically by serial sectioning and clearing to study the correlation between flower morphology and developmental stage. On the basis of these data, florets with visible stigma and receptive "curling" surfaces were chosen for embryo sac (ES) isolation. In such florets, ~20% of the ovules were unfertilized; fertilized zygote-stage ES (~75% of ovules) or ES containing two-celled proembryo occurred in the remaining ovules. ES were dissected manually using needles under a stereomicroscope or were treated with enzymes for 4–5 h after manual isolation. The viability of ES isolated without enzymes was more than 90% as assessed by fluorescein diacetate staining, and decreased to ~3% after 72 h of culture. The use of enzymes during isolation resulted in diminished ES viability, suggesting that removal of the protective layers of ovular cells may be part of the problem. Another factor affecting ES viability is medium osmolality. Living ES were then cultured in vitro. On liquid medium containing 9% sucrose, globular embryos developed in ~10% of zygote-stage ES, but further growth of the embryos was abnormal and callus was produced. Transfer of embryo-derived callus to solid Murashige-Skoog medium supplemented with 1-naphtaleneacetic acid and kinetin resulted in organogenesis. When ES were co-cultured with androgenetic microspores and microspore-derived embryos of Brassica napus, ~11% of the ES showed growth and development. Embryological study of the cultured ES revealed outgrowth of endothelium.     

A new name in <Emphasis Type="Italic">Pavetta</Emphasis> L. (<Emphasis Type="Italic">Rubiaceae</Emphasis>)

Summary  The name Pavetta modesta (Hiern) S. E. Dawson is a later homonym of P. modesta Bremek. Pavetta crystalensis is proposed as a new name.     

Chromosomes are eliminated in the symmetric fusion between <Emphasis Type="Italic">Arabidopsis </Emphasis><Emphasis Type="Italic">thaliana</Emphasis> L. and <Emphasis Type="Italic">Bupleurum scorzonerifolium</Emphasis> Willd.

In order to investigate chromosome elimination in symmetric somatic hybridization between Bupleurum scorzonerifolium and Arabidopsis thaliana, protoplasts were isolated from suspension cultures of both A. thaliana and B. scorzonerifolium parents. Biparental protoplasts were mixed at a rate of 1.5:1 and fused with PEG-method. After protoplast fusion, the products were cultured in the P5 liquid medium for microcallus formation. Single cell lines formed from microcalli after subculturing on the MB1 (Xia and Chen, Plant Sci 120:197–203, 1996) solid medium. The putative somatic hybrid cell lines were identified by cytological and molecular analysis. Of the 132 somatic cell lines generated, 16 were identified as somatic hybrids, with the phenotypes resembled B. scorzonerifolium parent. These hybrids showed a complete set of B. scorzonerifolium chromosome and 0–2 small chromosome(s) of A. thaliana. A few of them showed nuclear and cytoplasmic SSR fragments of A. thaliana. These hybrid cell lines could differentiate to green spots, buds/leaves through complementation of regeneration ability. The chromosomes elimination of A. thaliana was discussed. Wang Minqin and Zhao Junsheng contributed equally to the work.     

Single nucleotide polymorphism genotyping by heteroduplex analysis in sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.)

Single nucleotide polymorphisms (SNPs) and insertions/deletions (indels) are increasingly used for cultivar identification, construction of genetic maps, genetic diversity assessment, association mapping and marker-assisted breeding. Although there are several highly sensitive methods for the detection of polymorphisms, most of them are often beyond the budget of medium-throughput academic laboratories or seed companies. Heteroduplex analysis by enzymatic cleavage (CEL1CH) or denaturing high-performance liquid chromatography (dHPLC) has been successfully used to examine genetic variation in several plant and animal species. In this work, we assess and compare the performance of both methods in sunflower by genotyping SNPs from a set of 24 selected polymorphic candidate genes. The CEL1CH method allowed us to accurately detect allele differences in 10 out of 24 regions using an in-house prepared CEL1 enzyme (celery single strand endonuclease 1, Apium graveolens L.). Similarly, a total of 11 regions were successfully optimized for dHPLC analysis. As a scaling-up approach, both strategies were tested to genotype either 42 SNPs/indels in 22 sunflower accessions from the local germplasm bank or 33 SNPs/indels in 90 recombinant inbred lines (RILs) for genetic mapping purposes. Summarizing, a total of 601 genotypes were efficiently analyzed either with CEL1CH (110) or dHPCL (491). In conclusion, CEL1CH and dHPLC proved to be robust, complementary methods, allowing medium-scale laboratories to scale up the number of both SNPs and individuals to be included in genetic studies and targeted germplasm diversity characterization (EcoTILLING).     

Decolourisation and dephenolisation potential of selected <Emphasis Type="Italic">Aspergillus</Emphasis> section <Emphasis Type="Italic">Nigri</Emphasis> strains – <Emphasis Type="Italic">Aspergillus tubingensis</Emphasis> in olive mill wastewater

Aspergillus section Nigri strains Aspergillus aculeatus Ege-K 258, A. foeditus var. pallidus Ege-K156, A. niger Ege-K 4 and A. tubingensis Ege-K 265 were used to treat olive mill wastewater (OMW) in an investigation aimed at exploring their dephenolisation and decolourisation ability and, consequently, the economic feasibility of using any or all of these strains in a pre-treatment step in the processing of OMW. Of these strains A. tubingensis Ege-K 265 resulted in an 80% decolourisation of twofold-diluted OMW and a 30% decolourisation of undiluted OMW; in addition, it was able to remove approximately 30% of all phenolic compounds in both twofold-diluted and undiluted OMW. We conclude that A. tubingensis Ege-K 265 could be effectively used in the pre-treatment step of a combined aerobic-anaerobic process to solve the environmental problems caused by OMW in Mediterranean countries.     

Life cycle of <Emphasis Type="Italic">Aylax hypecoi</Emphasis> (<Emphasis Type="Italic">Insecta: Hymenoptera: Cynipidae</Emphasis>), a gall inducer on <Emphasis Type="Italic">Hypecoum</Emphasis> ssp. (<Emphasis Type="Italic">Papaveraceae</Emphasis>)

The life cycle and developmental stages of Aylax hypecoi (Trotter, 1913, Hymenoptera: Cynipidae: Aylacini) were studied in detail. Aylax hypecoi is known to induce galls in fruits of two Hypecoum species — H. imberbe and H. geslini (Papaveraceae) and the larva develops in host plant fruits. The morphology and development of egg, larva and pupa were investigated, which has previously not been done. The shape and size of terminal-instar larvae and associated galls are sex-specific. Overwintering stage, adult emergence and flying periods, and egg productivity were studied also.     

Mapping species differences for adventitious rooting in a <Emphasis Type="Italic">Corymbia torelliana</Emphasis> × <Emphasis Type="Italic">Corymbia citriodora</Emphasis> subspecies <Emphasis Type="Italic">variegata</Emphasis> hybrid

Quantitative trait loci (QTL) detection was carried out for adventitious rooting and associated propagation traits in a second-generation outbred Corymbia torelliana × Corymbia citriodora subspecies variegata hybrid family (n = 186). The parental species of this cross are divergent in their capacity to develop roots adventitiously on stem cuttings and their propensity to form lignotubers. For the ten traits studied, there was one or two QTL detected, with some QTL explaining large amounts of phenotypic variation (e.g. 66% for one QTL for percentage rooting), suggesting that major effects influence rooting in this cross. Collocation of QTL for many strongly genetically correlated rooting traits to a single region on linkage group 12 suggested pleiotropy. A three locus model was most parsimonious for linkage group 12, however, as differences in QTL position and lower genetic correlations suggested separate loci for each of the traits of shoot production and root initiation. Species differences were thought to be the major source of phenotypic variation for some rooting rate and root quality traits because of the major QTL effects and up to 59-fold larger homospecific deviations (attributed to species differences) relative to heterospecific deviations (attributed to standing variation within species) evident at some QTL for these traits. A large homospecific/heterospecific ratio at major QTL suggested that the gene action evident in one cross may be indicative of gene action more broadly in hybrids between these species for some traits.     

Synthesis of orthogonally protected (<Emphasis Type="Italic">3R</Emphasis>,<Emphasis Type="Italic">4S</Emphasis>)- and (<Emphasis Type="Italic">3S</Emphasis>,<Emphasis Type="Italic">4S</Emphasis>)-4,5-diamino-3-hydroxypentanoic acids

Summary.  The paper describes two methods of the synthesis of ethyl (3R,4S)- and (3S,4S)-4-[(benzyloxycarbonyl)amino]-5-[(tert-butyloxycarbonyl)amino]-3-hydroxypentanoates, useful for the syntheses of edeine analogs. Differently N-protected (S)-2,3-diaminopropanoic acid was used as a substrate in both procedures. The absolute configuration of newly generated asymmetric carbon atoms C-3 in β-hydroxy-γ,δ-diamino products was assigned by means of ¹H NMR spectroscopy after their transformation into corresponding piperidin-2-ones. Received May 24, 2002 Accepted October 10, 2002 Published online December 18, 2002 Acknowledgment The authors are indebted to the Faculty of Chemistry, Technical University of Gdańsk for financial support. Authors' address: Zbigniew Czajgucki, M. Sc., Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Technical University of Gdańsk, 11/12 Narutowicza St., 80-952 Gdańsk, Poland, Fax +48 58 347 11 44, E-mail: zmczaj@wp.pl     

Seasonal changes in water source of four families of loblolly pine (<Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="Italic">taeda</Emphasis> L.)

Source water utilized by four families of loblolly pine (Pinus taeda L.) was assessed by comparing the H isotope composition ('D) of xylem sap and of soil water from four depths (0-20 cm, 20-40 cm, 1.2 m, and 2.1 m) across 1 year. Soil water 'D values varied with soil moisture content in the well-drained, sandy site and at each of the four soil depths. In September and November 1997 and May through November 1998, xylem sap 'D values closely matched the soil water 'D values of the upper soil horizons (0-20 and 0-40 cm) and, therefore, reflected significant water uptake from upper regions of the soil profile. In March 1998, xylem sap 'D values closely matched the soil water 'D values of the 1.2 m soil depth and, therefore, indicated that trees during this portion of the growing season were obtaining their water from deep in the soil profile. Analysis of source water use with a two-ended mixing model in the 3 months of collection that exhibited a range of soil water 'D values across the soil profile confirmed that trees utilized different sources of water depending upon season of the year. In September 1997 and November 1998, source water uptake was primarily from the upper soil profile while in March 1998, source water uptake was from deep in the soil profile. With few exceptions, we did not find striking differences in source water use between drought-hardy families and those that were locally adapted.     

Molecular mapping of an apical branching gene of cultivated sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.)

Commercial hybrids of cultivated sunflower (Helianthus annuus L.) are obtained by crossing a cytoplasmic male sterile line (A-line) with a restorer pollinator (R-line). The incorporation of a recessive branching trait to extend the pollination period of R-lines during hybrid seed production is laborious and time-consuming. By using target region polymorphism (TRAP) and bulked segregant analysis (BSA), we identified 15 TRAP markers linked to the b(1) (branching) locus in a population of 229 F(2) plants derived from a cross between nonbranched (HA 234) and branched (RHA 271) lines. TBr4-720 and TBr8-555 markers were linked to the b(1) gene in the coupling phase at 0.5 cM (0.004 recombination frequency). The Tbr20-297 and Tbr20-494 markers flanked the b(1) locus in the repulsion phase at genetic distances of 7.5 and 2.5 cM, respectively. Tbr19-395, also in the repulsion phase, mapped at 3.8 cM from the b(1) locus and on the opposite side of the marker Tbr20-297. The 8A1 and 15B3 restriction fragment length polymorphic (RFLP) markers of linkage group (LG) 16 of the RHA 271 x HA 234 cultivated sunflower map anchored the b(1) LG onto the RFLP map. Polymerase chain reaction (PCR)-based markers tightly linked to the recessive b(1) gene have been developed. Their identification and the incorporation of the LG containing the b(1) locus onto an RFLP map will be useful for marker-assisted selection (MAS) in breeding programs and provide the bases for map-based cloning of this gene.     

Effects of <Emphasis Type="Italic">crp</Emphasis> deletion in <Emphasis Type="Italic">Salmonella enterica</Emphasis> serotype Gallinarum

Background  

Salmonella enterica serotype Gallinarum (S. Gallinarum) remains an important pathogen of poultry, especially in developing countries. There is a need to develop effective and safe vaccines. In the current study, the effect of crp deletion was investigated with respect to virulence and biochemical properties and the possible use of a deletion mutant as vaccine candidate was preliminarily tested.     

Alternative mating tactics of the gobiid fish <Emphasis Type="Italic">Bathygobius</Emphasis><Emphasis Type="Italic">fuscus</Emphasis>

The reproductive ecology of the gobiid fish Bathygobius fuscus was studied at Nobeoka, Miyazaki, Japan. Males of this species maintain small rock holes as a nest and females spawn an egg mass on the wall of the nest. The males employed two forms of mating tactic: nest holding and sneaking. A nest holder stayed in the nest and waited for a female to visit, whereas a sneaker intruded into a nest while a pair was engaged in reproduction. Males larger than 55 mm standard length were always nest holders; those of smaller size employed both tactics. As the larger males excluded the smaller males, the latter did not occupy a nest hole. With a decrease in the number of larger males, smaller males changed their mating tactic from sneaking to nest holding. The results suggest that male Bathygobius fuscus adopt a conditional strategy whereby they change their tactic depending on their social status. Electronic Publication