bluuebunny/crossref_metadata_2025_split huggingface dataset:
Duplication of the Bx7 high‐molecular‐weight glutenin subunit gene in bread wheat (Triticum aestivum L.) cultivar‘Red River 68′
Authors: D'Ovidio R. , Masci S. , Porceddu1 E. , Kasarda D. D. 
Published: April 2006

AbstractSDS‐PAGE analysis of seed proteins of the cultivar‘Red River 68’showed a considerably higher staining intensity of the band corresponding to HMW‐GS Bx7 relative to the equivalent band in the cultivars‘Chinese Spring’and‘Cheyenne’. Southern blots of restriction enzyme fragments from DNA of these three cultivars were analyzed densitometrically to reveal that the band corresponding to the Bx7 gene of‘Red River 68’had a double staining intensity compared to the equivalent bands from the other two cultivars, which indicates that in‘Red River 68’a duplication of the Bx7 gene has occurred. Although the possibility of the gene copy being a pseudogene was not ruled out, the greater amount of protein corresponding to Bx7 in‘Red River 68’most likely is in accord with an increase in active gene number. SDSPAGE analysis of the proteins showed also that the mobility of Bx7 in‘Cheyenne’was slightly different from the mobilities of the Bx7 subunits of‘Red River 68’and‘Chinese Spring’. The same difference was observed at the gene level by PCR amplification of the genes encoding these subunits.
Resistance and tolerance to leaf rust in Ethiopian tetraploid wheat landraces
Authors: Andenow Y. , Hullukal M. , Belay G. , Tesemma1 T. 
Published: April 2006

AbstractInfection type to leaf rust (Puccinia recondita f. sp. tritici) in Ethiopian tetraploid wheat (Triticum turgidum L.) landraces is almost invariably susceptible and disease severity is usually high. However, such wheats produce a stable yield and seeds are less shrivelled, relative to disease severity. Using 10‘pure‐line’genotypes, the effect of the disease on kernel weight and grain yield was studied to detect whether some form of incomplete resistance or tolerance was involved. Genotypes exhibited significant differences for mean disease severity. Percentage losses varied from 3.9 to 14.4% for kernel weight and from 2.8 to 31.3% for grain yield. Regression analysis revealed a significant linear relationship (r = 0.66, P < 0.05) between mean percentage loss and mean disease severity for kernel weight but not for grain yield. Only one genotype sustained significant losses of both kernel weight and grain yield, and was therefore classified as susceptible. Genotypic differences for both traits and the negative correlation (r = ‐0.87, P < 0.01) between them complicated interpretation of the data. Generally, however, the results indicated that incomplete resistance, possibly partial resistance, is present when one considers kernel weight. For grain yield, tolerance was also implicated since the variation could not be explained by differences in disease severity, and percentage loss did not appear to be a function of disease severity.
Comparative seed yield performance of high‐by‐high and low‐by‐high crosses in flax *
Authors: Tadesse1 N. , Lay C. , Dybing C. D. 
Published: April 2006

AbstractSuccessful identification of a desirable segregant depends partly on the parents chosen to make the crosses. This experiment was conducted to compare performance and genetic variability for seed yield, yield components, agronomic traits and harvest index of lines derived from low‐ and high‐yielding flax (Linum usitatissimum L.) crosses, and to identify important yield components for flax seed yield improvement. The lines chosen as high yielding parents for this experiment were‘Linott’and 'Summit; and the low yielding parents were‘Grant’and Ci2395. The high‐yielding lines produced significantly more seeds per boll and had a higher harvest index than the low‐yielding lines. Evaluation of 161 F2:6 lines from four crosses among these lines showed that the greatest genetic variability, highest cross average, and highest F6 line seed yield occurred in the low x high cross,‘Grant’x‘Linott’. All low X high crosses exhibited higher genetic variances for seed yield than the high x high crosses. The high x high cross 'Summit’x‘Linott’had low genetic variance for seed yield. Number of bolls per area was determined by linear regression, path coefficient analysis, and stepwise multiple regression analysis to be the most important component of seed yield. This study showed that hybridization of low and high‐yielding flax lines may be useful to increase genetic variability and obtain high‐yielding flax lines.
A specific PCR assay for resistance to biotypes 1 and 2 of the rosy leaf curling aphid in apple based on an RFLP marker closely linked to the Sd1 gene
Authors: Rochf1 P. , Arke G. van , Vanheusden A. W. 
Published: April 2006

AbstractThis report describes the conversion of a restriction fragment length polymorphism (RFLP) marker (the 2B12a locus). linked to the Sd1 aphid resistance gene, to a polymerase chain reaction (PCR) based marker. A section of the 2BI2 probe was sequenced and two primers were designed lo amplify this sequence in the cultivars‘Prima’and‘Fiesta’: all the amplification products were the same size. After sequencing. two specific 24‐mer oligonueleotides were synthesized (DdARM‐51 and DdAR.M‐32) to exploit a single base‐pair difference. These primers were used to screen 44 plants from the‘Prima’x‘Fiesta’family and generated a single amplification product (196bp). in approximately half of the seedlings, which was linked to the resistance gene Sd1,. The DdARM primer combination was used to evaluate a range of apple cultivars and selections, including some varieties derived from‘Cox’and alternative sources of resistance reported in the literature. In parallel with this work, the phenotypic response of the same genotypes was either confirmed or determined in replicated glasshouse tests. The sequence characterized amplified regions (.SCAR) marker was amplified in all the resistant plants, with the exception of‘Northern Spy’and 3760 (the sources of Sd2 and Sd3 resistance, respectively), but never in the susceptible plants. The possible role of this marker in a marker‐assisted breeding strategy, and its compatibility with a SCAR marker linked to the I, gene for resistance to apple scab. is discussed.
Pollen‐mediated gene flow in an autogamous crop: Foxtail millet (Setavia italica)
Authors: WANG T. Y , CHEN H. B. , DARMENCY H. 
Published: April 2006

AbstractGene How is a key concern associated with the eonlamination of seed multiplication iields and the use of transgenic crops. The release of herbicide‐resistant germplasnis and the use of male‐sterile varieties make foxtail millet (Sviaria ilalicii) an appropriate material to inves‐tigate this concern. Pollen dispersal from pollen donor sources and gene tlow in fertile and male‐slerile varieties of fortail millet were investigated in experiments in China and France. Although foxtail millel is mainly autogamous (less than 2% oiitcrossing), pollen from a 5m diameter plot could fertilize a tertile variety up to 24 ni away, and a male‐sterile variety up to 40m. Negative exponential and WeibuU fnnctions were used to tit the relationships between percentage and number i.A iubrids per cm of ear with distance from the pollen source. Wind velocity and direction resulted in variations of gene How intensity, but did nol change liie slope ofthe regression equations. Pollen competition for available target ovules was observed up to 2 m away from a 1 m diameter pollen source. The percentage of pollen grains that fertilized ovules outside the pollen donor source was 1.4% of the total pollen grain produetion. For every iflO pollen grains released under lieid conditions 1.5 seeds were produced. The probability funetion of pollen dispersal for one donor plant was calculated. It allowed predictions of gene How accord‐ing to lield shapes, estimations of isolation distances to preserve /ariety purity against pollen contamination, and the fornuiiation of efficient male/female ratios Ibr hybrid seed production.
Heritility of field resistance to potato leafroU virus in cultivated potato
Authors: BROWN C. R. , CORSINI D. , PAVEK J. , THOMAS P. E. 
Published: April 2006

AbstractPotato progenies in a line x tester mating design and the clonal parents were screened for field resistance to potato leafroll virus (PLRV) to determine the heritability of this trait. Twelve advanced potato clones or varieties were crossed as pistillate parents to two pollen testers. The seedling progenies and clonal parents were exposed to aphid‐transmitted potato leafroll virus for two growing seasons. Cumulative infection by potato leafroll virus was determined by post‐season sero‐logical indexing of foliage grown from sprouted tubers after 2 years of exposure. Narrow‐sense heritability was estimated from regression of mid‐parent on progeny as h = 0.72. This estimate indicates a high level of useabie genetic variance for PLRV resistance in advanced breeding materials. Although variation in resistance to PLRV appears to be a quantitative trait in susceptible and moderately resistant clones, per‐formance of the most resistant parents suggests that genes with major effects may be present. These results are similar to the conclusions of other researchers who found one or two genes controlling the pheno‐types of extreme resistance, resistance to infection, or suppression of virus titre.
Response to early generation selection for grain yield and harvest index in bread wheat (T, aestivum L.)
Authors: Borghi B. , Accerbi M. , Corbellini M. 
Published: April 2006

AbstractThe availability of a reliable selection criterion for the identification of the most productive genotypes in early generations represents a crucial point in many breeding programs. The findings reported in the literature concerning the effectiveness of early generation testing for grain yield (GY) or harvest index (HI) are contradictory.In this work, we measured the response to selection for GY and HI applied in different generations, from F2 to F6 in nine segregating populations previously screened in F2 by means of visual selection. Genetic variability for HI and GY was found in most of the segregating populations. However, GY of spaced plants in F6 and F3 generations was weakly correlated with yield of F4 and successive generations grown at normal seed density. HI was of limited value as an indicator of yield potential.
Molecular breeding for the BaMMV/BaYMV resistance gene ym4 in winter barley
Authors: Tuvesson S. , Post L. V , ÖHlund R. , Hagberg P. , Graner A. , Svitashev S. , Schehr M. , Elovsson R. 
Published: April 2006

AbstractThe aim of this investigation was to develop a procedure for the largescale molecular breeding for ym4, allowing resistance to BaMMV/BaYMV to be fixed in early breeding generations of winter barley. A codominant STS marker derived from the restriction fragment length polymorphism marker MWG838 for the ym4 resistance gene was combined with a new and easy procedure for preparing leaf samples for polymerase chain reaction (PCR), theoretically allowing one person to extract DNA from 5000 samples in a single day. In the procedure for molecular breeding for ym4, all steps, including leaf sampling, DNA extraction, PCR amplification and digestion with restriction enzyme were assembled in microtitre plates allowing multipipetting throughout the procedure, including the loading of gels. The method is amenable to further automation with the aid of a robot arm. Double haploid (DH) lines, as well as F2 and F4 breeding lines were analysed and, based on markers, homozygous and heterozygous BaMMV/BaYMV resistant plants were identified for further breeding. The winter barley breeding programmes were modified to include marker‐based selection for BaMMV/BaYMV resistance on DH or on F2 individuals, which had been preselected for mildew and leaf rust resistance.
Identification of two new genes conferring resistance to rice blast in the Chinese native cultivar ‘Maowangu’
Authors: Pan Q. H. , Wang L. , Ikehashi H. , Yamagata H. , Tanisaka T. 
Published: April 2006

AbstractThe Chinese native rice cultivar ‘Maowangu’ expresses a high level of resistance to many races of rice blast (Pyricularia grisea) collected from North China and Japan. ‘Maowangu’ was crossed with 10 Japanese differential cultivars and the susceptible Chinese cultivar ‘Lijiangxintuanheigu’ (LTH). Allelism tests were conducted in the F2 populations with rice blast races. The resistance of ‘Maowangu’ was governed by two dominant genes which were non‐allelic to the resistance genes at seven loci: Pi‐a, Pi‐i, Pi‐k, Pi‐z, Pi‐ta, Pi‐b, and Pi‐t. To identify the two resistance genes, two F3 lines of ‘Shin 2/Maowangu’ segregating 3R:1S were selected for linkage tests in 1994. One was linked to marker genes C and Amp‐3 on chromosome 6 with recombination frequencies of 35.8 ± 6.4% and 42.1 ± 6.2%, respectively, and the other to Amp‐1 on chromosome 2 with a recombination frequency of 37.6 ± 6.0%. To confirm these results, two F3 lines of ‘LTH/Maowangu’ were selected for linkage tests in 1995. The one was linked to Amp‐3, and other was linked to Amp‐1, with recombination frequencies of 36.9 ± 3.1% and 34.3 ± 3.2%, respectively. The two genes on chromosomes 6 and 2 were designated Pi13(t) and Pi14(t), respectively.
Patterns of genetic diversity in landraces of common bean (Phaseolus vulgaris L.) from Galicia
Authors: Escribano M. R. , Santalla M. , Casquero P. A. , de Ron A. M. 
Published: April 2006

AbstractKnowledge of patterns of genetic diversity among existing cultivars helps to broaden the genetic base of new cultivars and maximizes the use of available germplasm resources. This study examined the organization of diversity for morphological traits in 66 landraces of cultivated common bean (Phaseolus vulgaris) from Galicia and its relationship with phaseolin seed protein diversity. Data on growth habit, seed and pod traits obtained from field evaluations at two locations during the 1989—91 cropping seasons were subjected to multivariate statistical analysis. Cluster analysis based on 14 quantitative variables and five qualitative variables identified 11 groups. The landraces were also characterized by phaseolin electrophoresis. The results allowed separation of these landraces into Middle and Andean American groups, which could be further divided into at least eight groups within the Andean American cultivars and three within the Mesoamerican cultivars. These groups in turn corresponded to the previously described races Nueva Granada and Peru of South American origin, and races Durango, Jalisco and Mesoamerica from the Middle American domestication centre. These results confirm the existence of two major groups of germplasm in the cultivated common bean landraces from Galicia, Mesoamerican vs. Andean American.
Identification of lily cultivars using isoelectric focusing of proteins from bulb scales and tissue culture bulblets
Authors: Booy G. , Wouters T. C. A. E. , Kleyn‐Noordijk Y. 
Published: April 2006

AbstractAn efficient procedure is described for cultivar identification in lily, based on polymorphism in bulb scale proteins analysed by isoelectric focusing (IEF). Seventy (84%) out of 83 cultivars from which in vivo bulbs were analysed showed a unique banding pattern. Analysis of in vitro bulblets from 62 commercial cultivars resulted in 47 (76%) unique banding patterns. Cultivars with identical protein patterns always belonged to the same cultivars classification group (i.e., Asiatic hybrids, Oriental hybrids or Lilium longiflorum). Protein bands characteristic for the cultivar groups have been found. The protein patterns appeared to be very consistent and were not affected by the soil‐type on which the bulbs were grown, long‐term bulb storage, different protein sample storage methods, in vitro growing conditions, or in vitro bulblet storage. However, in six out of 10 cultivars from which in vivo bulbs and in vitro bulblets were analysed, protein patterns from in vivo bulbs consisted of a greater number of, and/or more intensely stained bands than those from in vitro bulblets of the same cultivar. The protein patterns appeared to be unsuitable markers for selection of reference cultivars for distinctness, uniformity and stability (DUS) testing as no relation was found between morphological characters and protein patterns. Cultivars with identical or very similar protein patterns were generally clearly distinct on the basis of morphological characters.
Association of leaf rust and powdery mildew resistance in a recombinant derived from a Hordeum vulgare × Hordeum bulbosum hybrid
Authors: PICKERING R. A. , STEEFFENSON B. J. , HILL A. M. , BOROVKOVA I. 
Published: April 2006

AbstractWhile studying powdery mildew resistance in a recombinant line (code 81882) derived from a Hordeum vulgare (cv. ‘Vada’) ×Hordeum bulbosum hybrid, a low infection type of resistance to leaf rust was observed. To determine the mode of inheritance of the leaf rust resistance and whether there was linkage between the two resistances, F2 and F3 progenies from crosses between 81882 and ‘Vada’ were inoculated with the leaf rust and powdery mildew pathogens. Southern blots were prepared using restricted DNA extracted from leaves of 82 F2 plants and four chromosome 2HS sequences were hybridized with the blots to define the length of the introgression. The leaf rust resistance appears to be inherited as a single dominant gene on chromosome 2HS, which co‐segregates with the powdery mildew resistance. There was an almost complete association between the resistances and the respective molecular markers, but it is likely that the strong linkage results from the frequent inheritance of the introgressed H. bulbosum DNA as an intact segment of chromatin with only low levels of recombination within the segment.
Increasing erucic acid content in Ethiopian mustard through mutation breeding
Authors: VELASCO L. , FERNÁNDEZ‐MARTINEZ J. M. , HARO A. de 
Published: April 2006

AbstractEthylmethane sulphonate (EMS) was applied to seeds of the Ethiopian mustard (Brassica carinata A. Braun) line C‐101. Bulk samples of M3 seeds from 8331 M2 plants were evaluated for the fatty acid composition of their oil by near‐infrared reflectance spectroscopy (NIRS) and by further gas chromatography on selected samples. A putative mutant, N2‐6230, showing very low oleic acid content (4.7% vs. average of 8.6% in C‐101) and erucic acid content within the range of variation of the line C‐101 (40‐49.3%) was identified. The M3 progeny of this mutant showed a wide segregation for erucic acid content (39.1‐57.9% vs. 41.8‐50.3% in C‐101), and maintained levels of oleic acid lower than in line C‐101. Selection for high erucic acid content in the M3 and M4 generations led to the fixation of this mutation in the M5 generation (52.2‐59.3% vs. 39.0‐47.6% in C‐101). This is the first high erucic acid line obtained in Brassica species through mutation breeding. Its utility in future programmes to develop very high erucic acid lines is discussed.
Identification of RAPD markers linked to the Ns locus in potato
Authors: Marczewski W. , Ostrowska K. , Zimnoch‐Guzowska E. 
Published: April 2006

AbstractUsing the RAPD method and bulked segregant analysis we identified four RAPD markers linked to a dominant gene Ns, responsible for a hypersensitive reaction of potato (Solanum tuberosum L.) to potato virus S (PVS) infection. The markers OPE15550, OPJ13500, OPG17450 and OPH19900 were found to be closely linked to the Ns gene in diploid potato clones. They are situated at 2.6, 3.3, 4.6 and 6.6 cM from Ns, respectively. As a source of the gene, clone G‐LKS 678147/60, which is known to carry Ns transferred from S. tuberosum ssp. andigena was used. These RAPD markers were not amplified in resistant tetraploid clones containing Ns derived from the clone MPl65 118/3, also having an andigenum origin. This suggests that there may be two separate loci of Ns in the sources identified, or different alleles with the same specificity at a single locus, or that the genetic background of tetraploids tested results in different RAPD amphlification patterns.
Analysis of total glucosinolate content and individual glucosinolates in Brassica spp. by near‐infrared reflectance spectroscopy
Authors: Velasco L. , Becker H. C. 
Published: April 2006

AbstractThis study was conducted to test the applicability of near‐infrared reflectance spectroscopy (NIRS) for estimating the total glucosinolate (GSL) content in samples of intact seed from a wide range of Brassica species, and to develop calibration equations to estimate simultaneously the percentage of individual GSLs. A total of 290 samples from 15 different Brassica species were scanned by NIRS and analysed for glucosinolate content by high‐pressure liquid chromatography (HPLC). A calibration equation for total GSL content was developed using 270 samples of 14 species in a range between 6 and 193μmol/g seed, resulting in an r2 of 0.99 in calibration and cross‐validation, and 0.95 in independent validation with 20 samples of Brassica rapa, a species not represented in the calibration. Furthermore, calibration equations to estimate the relative amount (mol/mol) of progoitrin, sinigrin, and gluconapin were successfully developed (r2 > 0.85 in cross‐validation) and validated with samples from species not included in the calibration. It was also possible to discriminate between entries with high and low values of glucoiberin, 4‐hydroxyglucobrassicin and glucoerucin.
Diallel analysis of four resistance components to Septoria tritici in six crosses of wheat (Triticum aestivum)
Authors: Simon M. R. , Cordo C. A 
Published: April 2006

AbstractFour resistance components, i.e. incubation period, latent period, maturation period and pycnidial coverage, were studied in a diallel cross of four wheat cultivars differing in susceptibility to Septoria tritici. Inoculations and evaluations were carried out at the fourth leaf stage for two years. A combined ANOVA for both years exhibited a significant interaction between crosses and years for maturation period. A separate ANOVA for each year was done for this trait. The combined ANOVA showed that crosses were significantly different for incubation, latent period and pycnidial coverage. Cross effects were also significant for maturation period in each year for the separate ANOVA. Year effects were significant for latent period and maturation period. General combining ability (GCA) was significant and preponderant for incubation period, latent period and pycnidial coverage. For maturation period, the separated ANOVA showed the significance of the GCA for both years. Specific combining ability (SCA) was significant for incubation and pycnidial coverage and for maturation in one year. The preponderance of the additive genetic variance for all traits indicates the possibility of selecting for them in order to obtain improved cultivars. Incubation period was inherited independently of maturation period and pycnidial coverage, indicating that combinations of some of those characters may lead to more effective and durable resistance.
RFLP variability in apricot (Prunus armeniaca L.)
Authors: de Vicente M. C. , Truco M. J. , Egea J. , Burgos L. , Arús P. 
Published: April 2006

AbstractThe level of polymorphism of the restriction fragment length polymorphisms (RFLPs) detected by 33 almond genomic and cDNA probes was studied in a set of 52 European and North‐American apricot cultivars. Eighteen of these probes were polymorphic and yielded a total of 48 scorable bands, allowing the identification of 45 different phenotypes. Most cultivars (43) had an individually distinguishable RFLP phenotype, and three of the five clusters with the same phenotype contained cultivars that were likely to be synonymous. The group of Spanish cultivars (25) had a lower level of polymorphism than the others, suggesting that bottlenecks may have occurred in the recent history of the apricot that have eroded its genetic variability.