bluuebunny/crossref_metadata_2025 huggingface dataset:
Parial resistance in the barley (Hordeum vulgare L.) cultivar ‘Chikurin Ibaraki 1’ to two PAV‐like isolates of barley yellow‐dwarf virus: allelic variability at the Yd2 gene locus
Authors: Chalhoub B. A. , Sarrafi A. , Lapierre H. D.
Published: April 2006

The Japanese barley cultivar, ‘Chikurin Ibaraki 1’, is partially resistant to the PAV serotype of barley yellow‐dwarf virus (BYDV), but its induced mutant line, Ea52, is susceptible. The inheritance of resistance in cv. ‘Chikurin Ibaraki 1’ to BYDV‐PAV was investigated. The F, and F2 plants of crosses of cvs ‘Chikurin Ibaraki 1’, Ea52, ‘Vixen’, carrying the Yd2 gene of resistance, and ‘Plaisant’, a susceptible French cultivar, were tested in growth chamber and field conditions. Isolate RG, against which ‘Chikurin Ibaraki 1’ is partially resistant in growth chamber and field conditions, and isolate 2t, which overcomes the partial resistance of ‘Chikurin Ibaraki 1’ in field conditions (Chalhoub et al. 1994) were used. The segregation of F2 plants of crosses between ‘Chikurin Ibaraki 1’ and the susceptible cultivars to isolate RG (one resistant to three susceptible) suggests that the resistance of ‘Chikurin Ibaraki 1’ is controlled by a single recessive gene. All 537 F2 plants of ‘Chikurin Ibaraki 1’×‘Vixen’ tested with isolate RG in growth chamber and field conditions were resistant. The F2 plants of this cross were all resistant to isolate 2t in growth chamber conditions but segregated with a ratio of one resistant to three susceptible in field conditions owing to the susceptibility of ‘Chikurin Ibaraki 1’ to this isolate. Results suggest that the resistance gene in ‘Chikurin Ibaraki 1’ is tightly linked or allelic with the Yd2 gene in ‘Vixen’. However, it differs from this gene in ‘Vixen’ in that it can be overcome by isolate 2t in field conditions.
Genotypic lipoxygenase variation in soybean seeds and response to nitrogen nutrition
Authors: Zougari A. , Guy S. , Planchon C.
Published: April 2006

Decreasing the lipoxygenase content of soybean (Glycine max (L.) Merr.) seed is a prerequisite for its increased use in human foods. These investigations aim to analyse the variation of lipoxygenase contents in relation to the genotype or the nitrogen nutrition of the plant. Four genotypes from a divergent selection for N2 fixation and the recurrent parent, Weber, were grown in pots, and two Bradyrhizobium japonicum strains (G.49 and SMGS1) were used. Dinitrogen fixation was estimated in situ using the acetylene–reduction assay. The lipoxygenase activity was determined polarographically on seeds taken from plants grown under controlled conditions in the presence or absence of symbiotic N2 fixation. The large genotypic variation observed for the lipoxygenase contents was enhanced by high N2 fixation. The variation range of lipoxygenase contents, which was obtained through the combination of the genotypic variation and the N2 fixation activity, was relatively large with a ratio of 2 on a seed dry–weight basis and a ratio of 2.6 when the total proteins were considered. Decreased lipoxygenase content and increased total protein content can thus be considered in parallel in a genetic context, together with more efficient N2 fixation.
Evaluating the effectiveness of isolation distances for field plots of oilseed rape (Brassica napus) using a herbicide‐resistance transgene as a selectable marker
Authors: Scheffler J. A. , Parkinson R. , Dale P. J.
Published: April 2006

The effectiveness of 200‐ and 400‐m isolation distances were evaluated for small‐scale trials of oilseed rape (Brassica napus L.). These distances have been used for previous transgenic release experiments and are commonly adopted for production of basic and certified breeders seed. A 400‐m2 donor plot contained plants with a dominant transgene conferring resistance to the herbicide glufosinate‐ammonium. This character was used as a selectable marker to measure the frequency of hybrid formation in 400‐m2 target plots of non‐transgenic rape. Seeds produced by the non‐transgenic plants were permitted to fall onto the plots and allowed to germinate. At the first true‐leaf stage, the plants were sprayed with glufosinate‐ammonium. Surviving plants were resprayed, and a subsample assayed for the presence of the transgene using a colorimetric assay and Southern‐blot analysis. The average frequency of hybridization over two replicates was 0.0156% at 200 m and 0.0038% at 400 m. These estimates are within the limits established for the production of basic seed (0.1%). Results indicated that bees were the most likely agent for long‐distance pollen dispersal.
Resistance to Leveillula taurica in pepper (Capsicum annuum) is oligogenically controlled and stable in Mediterranean regions
Authors: Daubeze A. M. , Hennart J. W. , Palloix A.
Published: April 2006

The resistance to Leveillula taurica from an african pepper line H3 Capsicum annuum) was evaluated and analysed, using the androgenetic haplodiploid progeny from an F1 hybrid between H3 and a susceptible line. Tests were performed in natural infection conditions in two locations (France and Sicily). Stable behaviour of the parental and haplodiploid lines was observed in both locations, confirming the high level and stability of this resistance source in Mediterranean countries. Heritability of resistance was high and genetic analysis suggested that it is under oligogenic control. However, the number of genetic factors involved in resistance depended on infection conditions: two or three genetic factors with additive and partial dominance effects appear sufficient to confer resistance at the beginning of the epidemic or in weak infection conditions. However, additional genes are necessary to slow down further disease progress and secondary infections and at least five genetic factors are necessary to confer resistance in severe infection. In this case, both additive and epistatic effects are significant. The transfer of this resistance into cultivars will require the use of artificial inoculation procedures to control the severity of the test.
The use of multilocation trials to select cultivars that are better than a control
Authors: Piepho H.‐P.
Published: April 2006

Multilocation trials are a common means for evaluating new cultivars or strains. Their statistical analysis is often based on multiple comparisons with one or more controls. The purpose of this paper is to demonstrate the use of the Chen‐Picket procedure for selecting cultivars that are better than a control, which does not require stringent statistical assumptions and allows conclusions about the probability that the selected subset contains all cultivars that are better than the control. This procedure appears preferable to the multiple t‐test, which is often used in the evaluation of yield trials.
In vitro selection for modified amino‐acid pathways in Triticum species
Authors: Lange F. D. , Brown P. T. H. , Kollmorgen J. F. , Lörz H.
Published: April 2006

In vitro selections were carried out to obtain mutant plants of Triticum aestivum L. and T. monococcum L. with modified amino‐acid pathways. Embryogenic callus cultures were selected with the amino acids L‐lysine plus L‐threonine and the amino acid analogues S‐2‐aminoethyl‐L‐cysteine, 5‐methyl‐L‐tryptophan and sulfometuron‐methyl. A number of plants were regenerated from these selections and tested for resistance at the whole‐plant level. Only plants from the selections with sulfometuron‐methyl proved to be resistant and these were characterized biochemically. Three different mutant lines could be detected. The resistance of these plants could be associated with an altered enzyme. Acetolactate synthase was less sensitive to inhibition. A discussion of the suitability of the selection agents is presented.
A genetic map of sugar beet (Beta vulgaris) based on RAPD markers
Authors: Uphoff H. , Wricke G.
Published: April 2006

Linkage analysis of sugar beet (Beta vulgaris L.) was performed with random amplified polymorphic DNA (RAPD)‐markers. From three segregating populations, a combined genetic map was constructed which comprises 85 RAPD, five isozyme, one RFLP marker and the genes for resistance against the nematode Heterodera schachtii Schm., one restorer locus for male sterility and the genes for annuality and hypocotyl colour. For mapping of the two unlinked restorer genes a statistical model was developed based on the maximum‐likelihood function.
Chromosomal location of a gene (Rkn‐mnl) for resistance to the root‐knot nematode transferred into wheat from Aegilops variabilis
Authors: Yu M. Q. , Jahier J. , Person‐Dedryver F.
Published: April 2006

Root‐knot nematode is a significant root‐parasite of common wheat. A dominant gene Rkn‐mnl for resistance was transferred into wheat from Acgilops variabilis. This gene was shown to be on chromosome 3B. Further analysis indicated that it is on the long arm of this chromosome and independent of the centromere.
Physical mapping of differences between the chloroplast DNAs of Beta vulgaris and B. webbiana
Authors: Kishima Y. , Yanai Y. , Kinoshita T. , Mikami T.
Published: April 2006

A physical map of Beta webbiana (a wild species of the section Pro‐cumbentes) chloroplast genome was constructed by localizing the cleavage sites of SmaI, PstI, PvuII, XhoI, and HindIII, and the map was then aligned with the map of sugarbeet (B. vulgaris) chloroplast DNA. This alignment shows 27 restriction‐site changes and 11 insertions/deletions, most of which occur in the large single‐copy region of the genome. A 0.7‐kb long mutation, located within an unidentified open reading frame (ORF2280) in the inverted repeat, was also found.
Inheritance and biochemical basis of resistance to Spilosoma obliqua Walker in interspecific crosses of soybean
Authors: Bhattacharyya P. K. , Ram H. H.
Published: April 2006

The inheritance and biochemical basis of resistance to Spilosoma obliqua Walker were studied in four interspecific crosses in soybean. Data from the F1, F2 and F3 generations indicated that resistance was controlled by one incompletely dominant gene. Chemical analysis for phenolic acids (benzoic acid, coumaric acid, tannic acid, 3,4 dicaffeoyl‐quinic acid, caffeic acid, p‐chloromercurobenzoic acid and chlorogen acid) did not show any clearcut relationship between resistance to S. obliqua and these phenolics.
Recommended isolation distances for the field multiplication of diploid tuber‐bearing Solanum species
Authors: Schittenhelm S. , Hoekstra R.
Published: April 2006

The sexual propagation of genebank accessions by hand pollination in the greenhouse is a very expensive and time‐consuming routine task. The self‐incompatibility of most diploid potato species allows their multiplication in isolated field plots, which is coupled with the advantage of the presence of natural pollinators and maintaining a high level of heterozygosity. The aim of this study was to determine the isolation distance required for minimizing pollen flow between neighbouring multiplication plots. The Solanum phureja clone IVP48 was used as the pollen donor since it possesses a dominant seed marker (‘embryo spot’). The centrally located pollen donor was surrounded by S. phureja recipient plots at distances of 10,20,40, and 80 m, respectively. The average pollen contamination ranged from 0.2% in the plots 80 m from the pollen donor to 5.1% in those 10 m away. In this study, procedures are suggested which will help to reduce cross‐pollination between accessions.
Use of electrophoresis for variety testing in carrot
Authors: Lallemand J. , Briand F.
Published: April 2006

Electrophoretic markers were used to describe varieties of carrot and tested for their use in distinguishing and identifying them. Seed proteins and ten enzyme systems (PGI, PGM, PGD, ACP, ADH, GOT, IDH, MDH, MR and SkDH) were studied in a set of varieties and selection lines. Using the proteins from bulk samples of more than 25 seeds per variety, consistent results were obtained which enabled the 38 varieties studied to be divided into 14 groups. Among the enzymes studied, PGI, PGM and PGD were found to be convenient for distinction purposes. They demonstrated the heterogeneity of the varieties and their combined use enabled most of them to be distinguished from one another. The use of electrophoretic markers for distinguishing varieties is discussed.
An agronomic and seed‐quality evaluation of noug (Guizotia abyssinica Cass.) germplasm in Ethiopia
Authors: Alemaw G. , Wold A. T.
Published: April 2006

Noug (Guizotia abyssinica Cass.), a member of the Compositae family, is grown as an oilseed crop in Ethiopia. The crop grows best on poorly drained, heavy clay soils. This study investigates the genetic variability of agronomic and seed quality characteristics of 241 noug germplasm collections from different parts of Ethiopia evaluated in a field test at Ghinchi, near Addis Ababa, Ethiopia, in 1992. The maturity of the noug accessions ranged from 132 to 168 days. Seed oil contents ranged from 39.8 to 46.9% with linoleic acid being the major fatty acid of the oil (76.6% of total fatty acids). The results of this field study indicated that genetic differences for maturity existed among the noug accessions. Oil content variation was continuous, without clear separation of accessions into oil content groups. It is concluded that the genetic variation observed among these accessions could be utilized in a breeding programme to develop high‐yielding, well‐adapted, high‐oil‐content noug cultivars for production in Ethiopia.
Assessment of transgene escape from Brassica rapa (B. campestris) into B. nigra or Sinapis arvensis
Authors: Bing D. J. , Downey R. K. , Rakow G. F. W.
Published: April 2006

The possibility of gene transfer between Brassica rapa and the two weedy species B. nigra and Sinapis arvensis was evaluated with the special concern on transgene escape from B. rapa to these two weedy species. B. rapa cultivar Tobin was reciprocally crossed to five and four strains of B. nigra and S. arvensis, respectively, using controlled cross. A single interspecific hybrid was obtained from the cross B. rapa×B. nigra, but no other cross was successful. The fertility of this hybrid on open pollination, selfing and backcrosses was investigated. The data of the present study and the information available to date indicate that gene transfer between B. rapa and B. nigra is possible. The chance of transgene escape from B. rapa to B. nigra depends essentially on whether natural cross can occur between these two species. Gene transfer between B. rapa and S. arvensis is at the most difficult, whereas trans‐gene escape directly from B. rapa to S. arvensis appears very unlikely.
Disease response of resynthesized Brassica napus L. lines carrying different combinations of resistance to Plasmodiophora brassicae Wor.
Authors: Diederichsen E. , Sacristan M. D.
Published: April 2006

Resistance responses of resynthesized Brassica napus lines to infection with Plasmodiophora brassicae were investigated. Lines that were derived from interspecific crosses between clubroot‐resistant B. rapa and resistant B. oleracea exhibited very broad and effective resistance in both greenhouse and field tests. When clubroot resistance was introduced into resynthesized lines from the B. oleracea parent only, the plants were mainly susceptible. Interspecific hybrids from the most resistant parental genotypes, i.e. B. campestris ECD‐04 and the B. oleracea cultivars ECD‐15 or ‘Bohmerwaldkohf’, were used to initiate a B. napus resistance‐breeding programme. These artificial rapeseed lines were resistant to isolates that were virulent on all B. napus differential lines and/or parental lines. Preliminary segregation analysis suggests that their resistance is due to at least two dominant and unlinked genes. In some cases progenies from selfed resynthesized plants exhibited resistance reactions that differed from those of the parental hybrid plant; this may have been the result of cytological instability.
Selection on pollen for linolenic acid content in rapeseed, Brassica napus L.
Authors: Jourdren C. , Simonneaux D. , Renard M.
Published: April 2006

In order to enhance the economic value of edible rapeseed oil, an improvement of quality is necessary. Mutagenesis of rapeseed resulted in a low linolenic acid content and a low ‘linolenic acid (CIS: 3) level to linoleic acid (CIS: 2) level’ ratio, that is, the linoleic desaturation ratio (LDR), in the seeds of the Canadian variety ‘Stellar’. As an early breeding marker for low linolenic acid content, the pollen fatty acid composition was determined on 80 doubled haploid plants derived from a single F1 hybrid obtained from a cross between ‘Stellar’ and a high CIS: 3 variety ‘Drakkar’. Fatty acid analysis on seed and pollen showed that the low CIS: 3 and the low LDR traits from the ‘Stellar’ variety were expressed in pollen and in seeds, and that a very close correlation (r = 0.88) existed between seed and pollen for these two traits. The inheritance of these traits is controlled by two major genes with additive effects, both in seed and pollen. However, minor genes also appeared to be expressed in pollen and seed. These genes may allow the production of plants with lower CIS: 3 levels than that of the low linolenic acid content parent. The efficiency of this new tool for early screening in breeding programmes is discussed.
Relationship between morphological variation and geographical origin or selection history in Lupinus pilosus
Authors: Clements J. C. , Buirchell B. J. , Cowling W. A.
Published: April 2006

Patterns of morphological diversity were examined in Lupinus pilosus in relation to geographical origins or selection history of accessions. There was significant variation among accessions for most architectural and reproductive characters in a field experiment in Perth, Western Australia. Late flowering was associated with resetted early growth, profuse branching and collection in higher rainfall sites. High yield and profuse podding on the main stem was associated with large pods and leaves, many seeds per pod, greater height to the first main‐stem pod, and collection in higher altitude sites.

Ten groups of accessions, identified by hierarchical cluster analysis, accounted for 79% of genotype and 69% of genotype x character sums of squares. One group, possibly taxonomically distinct from the others, consisted exclusively of wild types from northern Israel with poor pod set and low seed yield, poor nodulation, pale foliage, and small leaves. Wild types from Turkey and Crete had rosetted early growth and were late flowering, and the Turkish group had extremely rapid mid‐season growth. Ornamental types from Europe or Australia with pink, purple or white flowers clustered together in an early flowering group with vigorous early growth. A smooth‐seeded type of L. pilosus was discovered in a group of short, late flowering and rough‐seeded types from Syria.
Isolation of triploid and tetraploid olive (Olea europaea L.) plants from mixoploid cv. ‘Frantoio’ and ‘Leccino’ mutants by in vivo and in vitro selection
Authors: Rugini E. , Pannelli G. , Ceccarelli M. , Muganu M.
Published: April 2006

This paper reports a procedure for isolating triploid and tetraploid olive plants, which have not been produced before either artificially or in nature. These polyploids were isolated from two mixoploid somatic mutants obtained earlier by treating Trantoio' and ‘Leccino’ plantlets with gamma radiation. The mixoploid mutants exhibit increased thickness of leaf, stem and root tissues, short internodes, a modified leaf lamina shape and a strong resistance to Spilocaea oleagina (Cast.) Hugh. In addition, they produce a mixture of normal drupes and some abnormally large ones, almost twice normal size. The variation in the nuclear DNA content of the mixoploid mutants is closely correlated with variation in their pollen size, crop capacity and the production of large fruit. Triploid genotypes with 69 chromosomes were isolated by germinating the seeds of these large fruits, collected from both the mixoploid mutants. Tetraploid plantlets, with 92 chromosomes, were obtained from cv. ‘Frantoio’ by selecting in vitro, during several proliferation phases, the shoots with obvate leaf shape which occurred among the shoots with normal lanceolate or intermediate leaf shape.
Genetic variability of tocopherol composition in sunflower seeds as a basis of breeding for improved oil quality
Authors: Demurin Y. , Skoric D. , Karlovic D.
Published: April 2006

The variability of seed tocopherol content in wild sunflower species, the expressivity of tph1 and tph2 mutations in different lines and the oxidative stability of sunflower oil with altered tocopherol and fatty acid composition were objectives of this research.

Near‐isogenic lines for three genes, i.e. Tph1, Tph2, and Ol, were developed and investigated. Tocopherol content was determined with TLC and HPLC, as well as fatty acid composition with GC of methyl esters. Rancimat tests were used to estimate the oxidative stability of the oil.

The seed tocopherol composition of wild sunflower species was shown to be uniform with a prevailing content of the α‐homologue (90‐99%). The genetic background of different near‐isogenic lines was found to influence expressivity of mutations for tocopherol composition. High content of strong antioxidants, such as β‐, γ‐, and δ‐tocopherols increased oil oxidative stability of linoleic and oleic types of oil by 1.2–3.0 times.

The breeding model of sunflower hybrids should include antioxidant and vitamin parameters balanced for oils of different applications.
Development of RAPD markers in tritordeum and addition lines of Hordeum chilense in Triticum aestivum
Authors: Hernández P. , Rubio M. J. , Martin A.
Published: April 2006

RAPD markers were developed for octoploid X Tritordeum (amphiploid Hordeum chilense × Triticum aestivum) and its parents. Two bread wheats, two H. chilense accessions and the two tritordeums synthesized with them were used. A total of 41 arbitrary decamer primers were tested, yielding 190 products that could be assigned to wheat, 185 to H. chilense and 108 that were nonspecific (present in wheat and barley). A total of 44 products were specific to one H. chilense line and 33 to the other 16 of the former were located on the chromosomes using a set of H. chilense in T. aestivum addition lines. The potential of RAPDs for developing addition lines or the detection of introgressions of H. chilense in bread wheat is discussed.
Quality evaluation of D‐zone omega gliadins in wheat
Authors: Johansson E.
Published: April 2006

One‐hundred and eighty‐one wheat cultivars and breeding lines of diverse origin, together with 409 and 540 Swedish spring and winter wheat breeding lines, respectively, were analysed by electrophoretical methods for D‐zone omega gliadins. Correlations were calculated between the D‐zone omega gliadin and high‐molecular‐weight (HMW) glutenin subunit patterns, with Zeleny volume or specific Zeleny volume. The results showed that simultaneous screening of D‐zone omega gliadins and HMW subunits of glutenin was possible, and that the variation in Zeleny volume was attributed approximately equally between these protein groups. Both protein patterns can be used as parameters when breeding for bread‐making quality. Positive relationships were found between gliadins d7 and d2 d4, and the specific Zeleny volume. Gliadins d11 d12 and the null allele of chromosome IB showed indications of negative relationships. Common D‐zone omega gliadin patterns in the Swedish winter‐wheat breeding lines were d2d4 and d11 d12 (67% of the lines), and the null allele of chromosome IB and d11 d12 (in 25%). Greater variation was documented in the spring breeding lines than in the winter lines.
Linkage between a major gene for powdery mildew resistance and an RFLP marker on chromosome 1R of rye
Authors: Wricke G. , Dill P. , Senft P.
Published: April 2006

DNA samples from an F2 progeny which segregated for resistance to powdery mildew were bulked for resistant and susceptible individuals. In a segregant analysis, genomic rye probes which had been localized previously in a linkage map of rye were systematically screened for polymorphisms between these bulks. An RFLP marker located on linkage group 1RS was found to be tightly linked to a dominant mildew resistance gene. This is the first publication mapping a major gene for mildew resistance in rye.
An assessment of the salt tolerance of wheat/Thinopyrum bessarabicum 5Eb addition and substitution lines
Authors: King I. P. , Orford S. E. , Cant K. A. , Reader S. M. , Miller T. E.
Published: April 2006

Lines of Triticum aestivum cv. Chinese Spring carrying an additional chromosome 5Eb from Thinopyrum bessarabicum or having chromosome 5A or 5D replaced by chromosome 5Eb were screened in hydroculture for tolerance to salt. The previously reported tolerance of the 5Eb addition line was confirmed and the two substitution lines were shown to have a higher level of survival in 175 mol/m3 NaCl than both the addition and the ‘Chinese Spring’ parent. Reasons for the better tolerance of the substitutions are discussed.
Effect of sulphur levels on transgenic double‐low Brassica napus plants expressing a seed‐specific gene encoding a methionine‐rich 2S albumin
Authors: Denis M. , Krebbers E. , Renard M.
Published: April 2006

The effects of supplying varying levels of sulphur to transgenic Brassica napus plants expressing the Brazil nut 2S albumin in their seeds were studied in the field. The aim was to determine if transgenic plants responded differently to such stress, and whether expression of the transgene would be effected. The transgenic plants were similar to normal plants in their response to sulphur stress. Increases in sulphur concentration were correlated with an increase in fresh and dry matter quantities as well as an increase in the carbon, nitrogen and sulphur levels in the vegetative parts of the plants. No effect on yield parameters was observed. Increasing sulphur levels resulted in an increase in the glucosinolate content, and shifts in fatty acid composition were observed. None of these changes could be correlated with the response of the transgene. The expression of the latter was altered at neither the mRNA nor The protein levels, presumably because the promoter used does not respond directly to sulphur level changes. The procedures used to create the transgenic plants in this work appear not to result in plants that respond to sulphur stress differently from normal plants in the ranges studied.
Genetic analysis of resistance to clubroot (Plasmodiophora brassicae Woron) in two Brassica oleracea groups (ssp. acephala and ssp. botrytis) through diallel analysis
Authors: Grandclement C. , Laurens F. , Thomas G.
Published: April 2006

Clubroot, caused by Plasmodiophora brassicae Woron, is a major disease of cruciferous crops and few sources of resistance have been detected and genetically studied in the Brassica oleracea species. In this study, two diallel mating systems using resistant kale lines and susceptible cauliflower lines were performed. Resistance was assessed from a disease index evaluated on young plants artificially inoculated with local isolates of the parasite.

Both general and specific combining ability effects (GCA and SCA) and partly reciprocal effects were demonstrated. Resistance inheritance was, however, characterized by a predominance of additive genetic effects (GCA). Three groups of parent lines could be separated; kale lines with very high resistance, kale lines with intermediate resistance and susceptible cauliflower lines. In the two kale groups, two genetically different resistance types were suggested and various recurrent selection procedures are proposed following the diallel results.
Variation of B subunits of glutenin in durum, wild and less‐widely cultivated tetraploid wheats*
Authors: Liu C.‐Y. , Shepherd K. W.
Published: April 2006

Three major types of B subunits of glutenin patterns were detected among 240 durum wheat lines collected from eleven countries by the one‐step one‐dimensional SDS‐PAGE procedure. Most commercial durum lines had the LMW‐2 type while extensive variation of other banding patterns was found for lines particularly from North African and Mediterranean region. A total of 281 wild and less‐cultivated tetraploid wheat lines (var. dicoczoides, Triticum dicoccum and T. polonicum) were also studied for the variation of low molecular weight glutenin subunits and extensive variation was found. The complexity of banding patterns observed among the T. turgidum species indicate a rich source of glutenin variation with a potential value to be used for quality improvement of cultivated wheat when their functional properties have been tested.
Combination of resistances to barley yellow mosaic virus and Rhynchosporium secalis by recurrent selection with repeated haploid steps
Authors: Dletzmann E. , Foroughi‐Wehr B.
Published: April 2006

The aim of this investigation was the incorporation of resistance to BaYMV and Rhynchosporium secalis into German winter barley varieties together with the maintenance of their high agronomic characters. The agronomic value of DH‐lines after two backcrosses and three haploid steps were compared with the original parents. Lines with similar or superior results could be selected for all the agronomic features evaluated. This method of recurrent selection with repeated haploid steps can therefore lead to the development of lines useful for practical purposes.
Field evaluation and selection of rice somaclonal variants at different altitudes
Authors: Bertin P. , Busocoro J.‐P. , Tilquin J.‐P. , Kinet J.‐M. , Bouharmont J.
Published: April 2006

A field experiment was designed to compare control with tissue culture‐derived plants of rice, and to study the effects of natural selection pressure applied to the first generation (R0) of in vitro plants on the performance of their progeny. Control‐ and R0 in vitro plants of four rice varieties from middle altitude in Burundi, i.e. Facagro 57′, Facagro 76′, ‘Kirundo 3’ and ‘Kirundo 9’, were cultivated at four different altitudes (800, 1380, 1650 and 1900 m). Several parameters concerning tillering capacity, plant height development and seed production were measured. The means for most measured parameters were higher in control plants than in the in vitro plants, while the higher variation coefficients and most extreme values were usually found in the in vitro plants. For each variety, the 20 control plants and 20 in vitro plants having the highest production were selected at each altitude of 1380 and 1650 m, and their progenies were cultivated on the same site at 1580 m. Among the plants arising from 1650 m, most maximum values, higher variation coefficients and, in some cases, higher means were found in the in vitro plants. In contrast, among the plants arising from 1380 m, higher means most usually corresponded to control plants, while the tendency for maximum values and variation coefficients were unclear. These results indicate the positive effect of natural selection pressure applied in the first generation to plants rising from tissue culture. They also demonstrate that considerable variation may be generated in vitro. The interest for plant breeding purposes is discussed.
Linkage map of prolamin loci Gli‐D4 and Gli‐D5 in hexaploid wheat
Authors: Rodríguez‐Quitano M. , Carrillo J. M.
Published: April 2006

By electrophoretic analysis of F2 progenies from crosses among the hexaploid wheat varieties ‘Cajeme 71’, ‘Ablaca’, ‘Anza’ and ‘Pané 247’, two new prolamin loci Gli‐D4 and Gli‐D5, were mapped on the short arm of chromosome ID. The Gli‐D4 locus controls gliadins of type γ and is situated on the short arm of chromosome ID between the centromere and the Gli‐D1 locus with a genetic distance of 10.1±2.4 cM from this locus. The Gli‐D5 locus controls gliadin type ω and was mapped 3.7 ± 0.8 cM from Gli‐Dl and located between Gli‐Dl and the telomere.
Complexity of the Gli‐A3 locus in bread wheat
Authors: Nieto‐Taladriz M. T. , Carrillo J. M.
Published: April 2006

Two bread wheat cultivars, ‘Ariana 8’ and ‘Cajeme 71’, and 129 F2, grains from the cross between them were analysed for gliadin composition. Two monodimensional (A‐PAGE and SDS‐PAGE) and two different two‐dimensional (SDS‐PAGE x SDS‐PAGE and A‐PAGE x SDS‐PAGE) electrophoretic methods were used. Parents differed at the Gli‐Al locus, detected by A‐PAGE. The SDS‐PAGE of the aqueous ethanol extractable protein under nonreduced conditions showed two bands of ‘Ariana 8’ and one of ‘Cajeme 71’, encoded by genes located 22 cM from the Gli‐Al locus, and therefore, located at the Gli‐A3 locus. This locus has been considered to contain genes coding for ω‐gliadins alone. The two‐dimensional maps of the parents showed that one band from ‘Ariana 8’ was an ω‐gliadin, but the other two bands, one from each parent, were γ‐gliadins. Results obtained indicated that GH‐A3, like Gli‐Al, is a complex locus coding for both ω‐and γ‐gliadins.
Estimation of outcrossing rate in landraces of tetraploid wheat (Triticum turgidum L.)
Authors: Tsegaye S.
Published: April 2006

A study was undertaken to assess the amount of natural outbreeding in tetraploid wheat landraces of Ethiopian origin. The study consisted of two trials which were planted separately at two locations representing different environmental conditions for two consecutive seasons. The design employed was the randomized complete block with three replications. Two polymorphic loci, glume pubescence and awn condition were utilized as markers. The rate of outcrossing was based on the number of hybrids found in the recessive class of each marker. The overall level of outcrossing was higher in the pure stand trial than in the mixed stand trial. A higher rate of outcrossing occurred in the higher altitude area in the pure stand trial while the opposite was the case in the mixed stand trial. The average rate of outcrossing due to the marker loci was also different, with the long awn displaying more outbreeding tendency. Both locational and seasonal differences in the amount of outcrossing were observed. Generally, the study has revealed that there is a considerable amount of outbreeding in the landraces and that this genetic factor could play a role in preserving variation in the landrace populations. The level of outcrossing detected in this study could have a bearing on the maintenance of the genetic purity of diverse breeding lines being handled together in a breeding nursery and varietal purity in seed multiplication.
R‐41, a sunflower restorer inbred line, carrying two genes for resistance against a highly virulent Spanish population of Orobanche cernua
Authors: Domínguez J.
Published: April 2006

The inheritance of resistance to a highly virulent population of sunflower broomrape (Orobanche cernua) has been studied in R‐41, a Spanish sunflower restorer inbred line. Using the cytoplasmic male‐sterile inbred line HA‐89 (cms; very susceptible to this population of broomrape) as a female parent, progenies of the cross with R‐41, i.e. Fl, F2 and BC1 to both parents, as well as the parental lines, were analysed for their reaction to the broomrape population EC‐94. The goodness of fit of the observed vs expected segregation ratios indicated that the inheritance of resistance to broomrape in line R‐41 is conferred by two independent dominant genes.
Genetic transformation of Brassica
Authors: Poulsen G. B.
Published: April 2006

Tissue culture regeneration of plants from Brassica species can be achieved from various explant types. Their performance, however, varies with the genotype and age of the explant and is sensitive to medium supplements and Agrobacterium cocultivation. Most Brassica transformations were carried out using Agrobacterium and it was established that nopaline and agropine strains of A. tumefaciens and A. rhizogenes, respectively, are the most efficient. Application of virulence gene induction is ambiguous. Binary vectors are mostly applied in spite of indications that cointegrate vectors are more efficient. Cotransformation is successful with two different bacteria or with one bacterium carrying both plasmids, however, it has proved problematic to integrate the two transgenes into separate loci. Transformations with wild type rol genes develop hairy roots, from which transgenic plants can be regenerated. Vectorless transformation is feasible with microprojectile bombardment of microspore derived embryos being the most promising.

Antibiotic markers providing resistance to kanamycin, hygromycin, and spectinomycin are applicable as selectable markers, while chloramphenicol is not suitable. Among herbicides, phosphinotricin gives good results while chlorsulfuron is unsuitable for in vitro selection. Major therapeutic antibiotics being successfully applied are carbenicillin, cefotaxime, amoxycillin, and ticarcillin. Standard methods for evaluating transgenic plants also have been applied to Brassica species. Some breeding objectives obtained through genetic transformation are presented.
Integration of AFLP markers into a linkage map of sugar beet (Beta vulgaris L.)
Authors: Schondelmaier J. , Steinrücken G. , Jung C.
Published: April 2006

The AFLP (amplified fragment length polymorphism) technique has been applied in establishing an extended linkage map of sugar beet. A total of 120 AFLPs were integrated into an existing linkage map based on RFLP markers. Four primer combinations yielded between 19 and 40 polymorphic bands in an F2 population consisting of 94 plants. The AFLP loci were evenly distributed over the nine linkage groups, with the exception of linkage group V where the number of AFLPs was significantly low. The AFLPs were found to be reproducible even against the background of different combinations of Taq DNA polymerases and buffers. However, the quantity of higher molecular weight fragments (>400 bp) was reduced when using plant DNA of poor quality as a template. The results of these experiments are discussed, together with possible applications of AFLPs in sugar beet breeding.
Cytogenetic studies in hexaploid Helianthus species and their F1 hybrids with cultivated sunflower, H. annum
Authors: Atlagić J.
Published: April 2006

Hexaploid sunflower species provide potential sources of desirable genes in breeding for resistance to pathogens as well as high protein and oleic acid content. The possibility of using them in sunflower breeding was studied by testing the crossability of hexaploid species to cultivated sunflower, by the analysis of meiosis and pollen viability in the F1 interspecific hybrids.

The hybrids were obtained from 16 combinations, with 1–18 F1 plants per combination. The F1 hybrids in general exhibited the dominant phenotype of the wild species. Sterility ranged from 0 to 87.5% per F1 combination, while pollen viability ranged from 43.0 to 70.2%.

Meiosis was almost normal in the species analysed but irregular in the F1 hybrids. Most of the meiocytes showed predominantly bivalents (86.79–90.22%), but univalents (0.00–4.99%) and the multivalents (8.23–10.09%) occurred as well. At anaphase I, chromosome bridges were detected in 6.88–8.48% of meiocytes. Fast chromosomes in meta‐phase I and lagging chromosomes in anaphase I and telophase II were observed in many meiocytes.
Somaclonal variation and improvement in chilling tolerance in rice: changes in chilling‐induced electrolyte leakage
Authors: Bertin P. , Bouharmont J. , Kinet J.‐M.
Published: April 2006

Excised leaves of four rice varieties, ‘Facagro 57’, ‘Facagro 76’, ‘Kirundo 3’, ‘Kirundo 9’, were chilled for six days at 10/5°C day/night, along with 11 somaclonal families arising from three of these varieties, which had been selected over four generations for improved chilling tolerance. At the end of the chilling treatment, electrolyte leakage from leaf pieces was followed for 12 h and compared with an unchilled control. With unchilled leaves, no varietal differences nor a rise in leakage over time were observed. Chilling induced higher leakages in all varieties, except in ‘Kirundo 3’ at the time of first measurement, and a continuous rise over time was found in all varieties. Varietal differences were detected, ‘Kirundo 3’ being the least affected, followed by ‘Kirundo 9’ and ‘Facagro 76’, and finally ‘Facagro 57’, which coincides with their ranking for chilling tolerance established through chilling survival tests. The leakages were generally lower in the somaclonal families than in the variety they originated from in ‘Kirundo 9’ and ‘Facagro 76’, while the opposite was observed in ‘Kirundo 3’. The significance and usefulness of electrolyte leakage measurement for chilling tolerance screening, and the potentials of somaclonal variation for chilling tolerance improvement are discussed.
General combining ability of six genotypes of spring wheat (Triticum aestivum) for biscuit‐making quality characteristics
Authors: Labuschagne M. T. , Coetzee M. C. B. , van Deventer C. S.
Published: April 2006

The first South African soft wheat breeding programme was initiated in 1990, consequently almost no information is available on soft wheat quality characteristics. The aim of this study was to determine general combining ability (GCA) of several spring wheats for biscuit‐making quality characteristics. A full dialled cross was made with five spring wheats with good biscuit‐making quality and a sixth hard wheat with poor biscuit‐making quality. Seventeen quality characteristics were measured. When the GCA to specific combining ability (SCA) ratios were calculated, strong additive gene action was shown for all characteristics, excluding flour colour and biscuit diameter, which suggested high heritabilities for most characteristics. None of the characteristics showed more non‐additive than additive gene action. Three of the soft wheat cultivars combined well for the characteristics important for biscuit‐making quality.
Use of androgenesis in intersubspecific hybrid rice breeding
Authors: Yan J. Q. , Xue Q. Z. , Wang Y. X.
Published: April 2006

Significant differences of callus induction, green plant regeneration and culture efficiency were observed among restorer lines and their hybrids in rice. Average callus induction percentage of F1, hybrids was about twice that of their parents. Twenty doubled haploid (DH) lines that showed normal fertility with both indica and japonica CMS lines, were selected as widely compatible restorers (WCRs). TG8 derived from CPSLO17/Minghui 63 not only showed normal fertility to both indica and japonica test varieties and CMS lines, but also exhibited superior agronomic traits, in particular short plant, desired plant type, high tillerability, large panicles, good grain quality and resistance to rice blast disease. Strong heterosis for yield was observed in crosses between indica or japonica CMS lines and TG8. TG8 possessed a dominant, widely compatible gene (WCG) that was inherited from the variety CPSLO17. Results confirmed that the anther culture technique is a quick and effective way of developing widely compatible restorers in rice and that it is applicable to the direct use of intersubspecific heterosis with the three‐line method.
Selection response for carbon isotope discrimination in a Triticum polonicum×T. durum cross: Potential interest for improvement of water efficiency in durum wheat
Authors: Hakimi A. Al , Monneveux P. , Deléens E.
Published: April 2006

This study has been conducted to evaluate the usefulness of carbon isotope discrimination (δ) in mature kernels as a criterion for the improvement of water‐use efficiency and yield under drought in durum wheat. For this purpose, Triticum durum‘Om Rabi 5’ was crossed with T. polonicum pseudochrysospermum 9 (Tp9) which has been found to be more drought tolerant and to have a lower carbon isotope discrimination value of the grain. The F2 population showed a wide segregation for carbon isotope discrimination. Further, divergent selections (selection of plants most different in carbon isotope discrimination) were made among individual F2 plants, and for carbon isotope discrimination in F3 progenies under field conditions. Selected F3 and F4 progenies were evaluated under field conditions for morphological and agronomical traits. Broad‐sense heritability (h2b), response to selection and realized heritability (h2r) were high. The narrow‐sense heritability (h2n= 0.37 ± 0.047) indicated that additive and dominance effects were involved in the genetic control of carbon isotope discrimination. Negative correlations were noted between carbon isotope discrimination and grain yield and between carbon isotope discrimination and biomass yield within years and generations. An explanation of this result is attempted by analysing the relationships between carbon isotope discrimination and several phenological and morphological traits influencing the water‐use efficiency. The divergent groups selected for low and high carbon isotope discrimination exhibited significant differences for days to heading, plant height, shape of the spike and number of spikelets per spike. Correlations were also found between carbon isotope discrimination and plant height, harvest index, shape of the spike, spike length, and number of spikes per plant. The potential use of carbon isotope discrimination as a criterion for the improvement of water‐use efficiency in durum wheat is discussed by considering the genetics of this trait (variability, heritability, response to selection) and also the associations with phenological and morphological traits.
Location of genes controlling resistance to greenbug (Schizaphis graminum Rond.) in Hordeum chilense
Authors: Castro A. M. , Martin A. , Martin L. M.
Published: April 2006

Wheat/Hordeum chilense disomic addition lines have been used to locate genes influencing resistance against greenbug (Schizaphis graminum Rond.) in specific chromosomes of H. chilense. H. chilense is a source of antixenosis, antibiosis and host tolerance to the greenbug, being resistant also to the Russian wheat aphid, the two key pests in wheat. For measuring antixenosis, the numbers of aphids per plant were recorded in a host free choice test; antibiotic resistance was determined by measuring the developmental time, the fecundity and the intrinsic rate of population increase of aphids reared on the different hosts, and host tolerance to aphids was evaluated by the leaf damage and the number of expanded leaves on the hosts after 3 weeks of infestation. The greenbugs belonged to a clone of biotype C.

Plant genes with positive effects for antixenosis were located on chromosome 1Hch. Genes with positive effects for antibiosis were located on three different chromosomes and those that prolonged aphid developmental time were located on chromosomes 5Hch and 7Hch while those that reduced the total fecundity were on 4Hch. Chromosome 7Hch accounted for host tolerance to greenbug.
Genetic analysis of some chlorophyll fluorescence and productivity parameters in barley (Hordeum vulgare)
Authors: Marcial L. , Sarrafi A.
Published: April 2006

Reciprocal crosses were made between five barley genotypes of diverse origin. Parents and 20 F1S were grown in a greenhouse in a randomized block design with three replications. Each replication consisted of one pot containing three plants. Chlorophyll fluorescence activity of the penultimate leaf (below the flag leaf) of the main stem in each plant was measured at two stages of development (six‐leaf stage and anthesis). At anthesis, and after measuring fluorescence parameters, a drought stress was applied. Yield components were measured at complete maturity. Statistical analysis for chlorophyll fluorescence parameters showed high genetic variability for the traits studied at both the six‐leaf stage and anthesis, but most fluorescence parameters had decreased by anthesis. General and specific combining abilities of a diallel analysis were significant for most of the characters studied. General combining ability (GCA) values were usually more important than those of specific combining ability (SCA), showing the importance of additive genetic control for the fluorescence traits. Reciprocal effects were not significant for the fluorescence traits studied. A high genetic variability was also observed for yield components. Additive gene effects for plant weight, spike number, spike weight, number of grains per plant and 1000‐grain weight were demonstrated. Potential photosynthetic activity (Rfd) at anthesis was positively correlated with plant weight, spike number per plant and 1000‐grain weight.