bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic Control of Vernalization, Day‐length Response, and Earliness per se by Homoeologous Group‐3 Chromosomes in Wheat
Authors: Miura H. , WOrland A. J. 
Published: April 2006

AbstractTo identify homoeologous group‐3 chromosomes that carry genes for vernalization, day‐length responses, and earliness per se, a series of aneuploid lines (mono‐somics and tetrasomics) and chromosome‐substitution lines in ‘Chinese Spring’ (CS) were surveyed under different vernalization and day‐length regimes in controlled environments. The results indicated that genes on all three chromosomes of group 3 can have striking effects on ear‐emergence time. The replacement of CS 3B by its homologues in ‘Lutescens 62’ and ‘Cheyenne’ produced an increased insensitivity to vernalization, while 3B homologues from ‘Ceska Presivka’ gave CS a remarkable sensitivity to vernalization. This provided evidence for multiple allelism at a new Vrn locus on chromosome 3B. A negative association between gene dosage and day‐length response was found in CS 3D which was thought to carry a gene for promoting insensitivity to day‐length. The behaviour of CS monosomic 3A and CS (Timstein 3A), in reducing numbers of days to heading independently of environmental stimuli, suggested the presence of earliness per se genes on this chromosome.
An Assessment of Variation for Nutritional and Non‐nutritional Carbohydrates in Lentil Seeds (Lens culinaris)
Authors: Frias J. , Vidal‐Valverde C. , Bakhsh A. , Arthur A. E. , Hedley C. 
Published: April 2006

AbstractThe levels of the raffinose family of α‐galactosides (raffinose, stachyose, verbascose and ciceritol) and of the nutritional carbohydrates (fructose, sucrose and starch) were determined in the seed of a range of lentil lines from germplasm collections and commercial Spanish cultivars. Significant levels of variation were found for all the measured characters, and particularly for the α‐galactosides. The greatest variation was found in verbascose content, which ranged from about 1 % of the seed dry weight to undetectable amounts. The relationship between these chemical components and morphological seed characteristics was assessed. The only significant relationship between the different groups of characteristics was a positive correlation between the level of verbascose and the average seed weight for each genotype.
The Genetics and Breeding Potential of Rht12, a Dominant Dwarfing Gene in Wheat
Authors: Worland A. J. , Sayers E. J. , Börner A. 
Published: April 2006

Abstract Rht12, a dominant dwarfing gene of wheat, was shown to be located distally on the long arm of chromosome 5A. Lack of recombination with the awn inhibitor B1 suggested that Rht12 is cither tightly linked to this gene or is, in this material, a pleiotropic expression of the gene. Linkage to β‐Amy‐A1 was also very tight, indicating that Rht12 is present on the segment of chromosome SAL ancestrally translocated from 4AL. The close linkage to β‐Amy‐A1 also suggests that Rht12 is not a homoeoallele of the commercially important GA‐insensitive dwarfing genes.Analysis of near‐isogenic lines in a number of genetic backgrounds showed that Rht12 reduces height without altering ear size and significantly increases spikelet fertility. However its successful utilization in breeding programmes will require careful selection since in some backgrounds the gene reduces grain numbers and grain size. In all backgrounds, Rht12 delayed ear emergence time by around 6 days. A delay of this magnitude could, in many environments, adversely affect yield if it is not neutralized by altering the balance of other genes determining ear emergence time.
Inheritance of Total and Individual Glucosinolate Contents in Seeds of Winter Oilseed Rape (Brassica napus L.)
Authors: Rücker B. , Röbbelen G. 
Published: April 2006

AbstractGenetic analyses were carried out with B. napus lines that differed in total content of individual glucosinolates (GSLs), as well as in their profile. Inheritance of total GSL content was studied with a complete F1 diallel mating of eight doubled haploid (DH) lines (5–120/μmol GSL/g dry seed) as well as with the segregating populations of two crosses between DH lines. Most of the genetic variability was caused by gca effects; heterosis was not important; heritability of GSL content was high (h2b, = 0.95, h2n= 0.87). For GSL contents below 20/μmol/g seed, heritability values reached h2b, = 0.69 and h2n, = 0.66. Low total GSL content was found to be controlled by 4–5 recessive genes with additive gene action. Alkenyl GSL profiles studied in F2 from resynthesized rapeseed lines were determined by four loci, two that are responsible for the elongation of the butenyl to pentenyl GSLs and two that are responsible for hydroxylation of alkenyl GSLs. Initial genetic studies of indolyl GSL contents from 0.1–4.5/μmol/g show that two or three genes may be involved. The frequency distribution of F2 phenotypes was virtually continuous due to both segregational and environmental variation. Genotypes with low alkenyl and low indolyl GSL contents were selected after crossing parents with low alkenyl/high indolyl and high alkenyl/low indolyl GSL content. The alkenyl GSL profiles are discussed with regard to the parental diploid species B. oleracea and B. campestris.
Efficient Production of Doubled Haploid Plants through Chromosome Doubling of Isolated Microspores in Brassica napus
Authors: Chen Z. Z. , Snyder S. , Fan Z. G. , Loh W. H. 
Published: April 2006

AbstractThree methods of chromosome doubling to produce doubled haploid plants from microspore cultures of Brassica napus were compared: colchicine treatment of microspore‐derived plants, microspore‐derived embryos, and isolated microspores. In the whole plant treatment, 53% of the treated plants set seed, but the treatment delayed plant growth and reduced seed set. When microspore‐derived embryos were treated with colchicine, the doubling frequency was 32% (compared to 15% for spontaneous doubling). Direct colchicine treatment of isolated microspores resulted in a doubling efficiency of 70 % of the whole plants. This treatment also stimulated embryogenesis in microspore culture, leading to increased plant regeneration. Thus, direct chromosome doubling of isolated microspores is efficient and more than 10 000 doubled haploid plants have been produced in this manner in the past three years in order to accelerate the plant‐breeding process.
Efficient In Vitro Shoot‐regeneration Systems in Cassava (Manihot esculenta Crantz)
Authors: Konan N. K. , Sangwan R. S. , Sangwan‐Norreel B. S. 
Published: April 2006

AbstractTwo different protocols for in vitro regeneration of cassava using zygotic embryos and nodal axillary meristems have been developed. In both cases, buds were regenerated directly from excised explants without an intervening callus phase after a two‐step culture procedure. In cotyledonary explants derived from zygotic embryos, prolific shoot formation occurred within 2—3 weeks on MS medium supplemented with 0.5—5 mg/1 BAP alone or in combination with 0.1 mg/1 NAA. Nodal explants with axillary meristems derived from aseptically grown seedlings or stem cuttings were used to initiate a round compact bulb‐like structure on MS medium containing 10 mg/1 BAP. These latter structures, when cultured on MS medium supplemented with 0.1 mg/1 NAA, 1 mg/1 BAP and 0.1 mg/1 GA3, produced multiple shoots. Somatic embryos isolated at the globular/torpedo stage from zygotic embryo explants were also capable of multiple shoot production on medium with 1 mg/1 BAP. Rooting of regenerated shoots exceeded 95 % in phytohormone‐free MS medium. No change in their ploidy levels was observed. Therefore, the protocols developed should be of use in the particle gun and Agrobacterium‐mediated genetic transformation of cassava.
Enhancement of RAPD Analysis by Restriction‐endonuclease Digestion of Template DNA in Wheat
Authors: Riede C.R. , Fairbanks D.J. , Andersen W.R. , Kehrer R.L. , Robison L.R. 
Published: April 2006

AbstractRandom amplified polymorphic DNA (RAPD) analysis has proven to be an effective procedure for molecular marker applications in plant breeding, although non‐specific amplification may limit its utility in some species. The objective of this study was to determine the effectiveness of restriction‐endonuclease digestion of template DNA for elimination of non‐specific amplification and generation of heritable RAPD markers. Restriction endonucleases digested wheat DNA to completion in amplification buffer, suggesting that the restriction endonuclease can be added directly to the reaction mixture prior to amplification. A 1‐h 37°C step was programmed into the thermal cycler for restriction‐endonuclease digestion which was followed immediately by amplification. Non‐specific amplification was reduced and DNA marker patterns were altered in digested samples when compared to undigested samples. Genetic segregation of two polymorphic markers tested in F5 inbred progeny fit expected 1:1 ratios. These results suggest that heritable DNA markers may be generated with reduction in non‐specific amplification when restriction‐endonuclease digestion of template DNA is conducted as part of the RAPD procedure.
Intergeneric Transfer (Rye to Wheat) of a Gene(s) for Russian Wheat Aphid Resistance
Authors: Marais G. F. , Horn M. , Du Torr F. 
Published: April 2006

AbstractAn octoploid triticale was derived from the F, of a Russian wheat aphid‐resistant rye, ‘Turkey 77’, and ‘Chinese Spring’ wheat. The alloploid was crossed to common wheat, and to ‘Imperial’ rye/‘Chinese Spring’ disomic addition lines. F2, progeny from these crosses were tested for Russian wheat aphid resistance and C‐banded. A resistance gene(s) was found to be associated with chromosome arm IRS of the ‘Turkey 77’ rye genome. A monotelosomic IRS (‘Turkey 77’) addition plant was then crossed with the wheat cultivar ‘Gamtoos’, which has the 1BL.1RS ‘Veery’ translocation. Unlike the IRS segment in ‘Gamtoos’, the ‘Turkey 77’‐derived 1 RS telosome did not express the rust resistance genes Sr31 and Ar26, which could then be used as markers. From the F, a monotelosomic 1 RS addition plant that was also heterozygous for the 1BL. 1 RS translocation was selected and testerossed with an aphid‐susceptible common wheat, ‘Inia 66’ Meiotic pairing between the rye arms resulted in the recovery of five euploid Russian‐wheat‐aphid‐resistant plants. One recombinant also retained Sr31 and Lr26 and was selfed to produce translocation homozygotes.
Analyses of Interactions of Wheat Cultivars in Tests for Resistance to Pseudocercosporella herpotrichoides
Authors: Lind V. , Züchner S. , Spanakakis A. , Thiele A. 
Published: April 2006

AbstractA total of 20 cultivars of winter wheat were tested by ELISA for resistance to Pseudocercosporella herpotrichoides in six environments and three growth stages. In a three‐factor statistical analysis, the contribution of the different factors to their respective interactions was studied. The genotype × environment interactions exerted a considerable influence which could be reduced by increasing the number of test locations. Environments with a high disease level were less suited to measuring resistance than those environments with a medium level. Estimates of heritability from 0.54 to 0.78 show that successful selection may be possible using ELISA. Significant correlations of quantitative resistance at different environments were only obtained under similar environmental conditions (the same location, the same year) and with P. herpotrichoides populations of similar composition (the same inoculum). The contributions of the individual cultivars to the genotype/ environment interactions were not significantly different, except for ‘Roazon’ and ‘Rendezvous’. Due to high environmental effects in growth stage H5, the determination of quantitative resistance was more reliable in younger stages (65, 75). Nevertheless, the use of the values from that late stage did not reduce the genetic parameters (σ2, h2) if they were combined with the earlier measurements.
A New Source of Resistance to Pseudocercosporella herpotrichoides, Cause of Eyespot Disease of Wheat, Located on Chromosome 4V of Dasypyrum villosum
Authors: Murray T. D. , de la Pena R. C. , Yildirim A. , Jones S. S. , Qualset C. O. 
Published: April 2006

AbstractResistance to Pseudocercosporella herpotrichoides in five wheat cultivars, accession W6 7283 of Dasypyrum villosum, and ‘Chinese Spring’ disomic addition lines of the D. villosum chromosomes IV, 2V, 4V, 5V, 6V and 7V, was evaluated in seedlings by measuring disease progress 6 weeks after inoculation with a β—glucuronidase—transformed strain of the pathogen and by visual estimates of disease severity. D. villosum and the disomic addition line of chromosome 4V were as resistant as wheat cultivars ‘VPM—1’ and ‘Cappelle Desprez’, but less resistant than ‘Rendezvous’. Resistance of the chromosome 4V disomic addition line was equivalent to that of D. villosum.‘Chinese Spring’ and disomic addition lines of IV, 2V, 5V, 6V and 7V were all susceptible. These results confirm Sparaguee's (1936) report of resistance in D. villosum to P. herpotrichoides and establish the chromosomal location for the genes controlling resistance. The presence of chromosome 4V in the addition line and its homocology to chromosome 4 in wheat were confirmed by Southern analysis of genomic DNA using chromosome group 4‐specific clones. This genetic locus is not homoeologous with other known genes for resistance to P. herpotrichoides located on chromosome group 7, and thus represents a new source of resistance to this pathogen.
Establishing Cytoplasmic Male Sterility in Brassica napus by Mitochondrial Recombination with B. tournefortii
Authors: Stiewe G. , Röbbelen G. 
Published: April 2006

AbstractFusion experiments between B. napus and X‐ray‐treated B. tournefortii protoplasts were carried out to develop cytoplasmic male sterility (ems) in B. napus. From the regenerants, six lines containing male sterile plants were selected; five lines segregated for male sterility, but one line (25–143) was completely male‐sterile from the beginning. Molecular analyses of mitochondrial (mt) and chloroplast (cp) DNA of B. napus, B. tournefortii, B. juncea and cms juncea indicated that the original cytoplasmic donor of the cms juncea‐system in B. napus was a B. tournefortii form, while the B. napus genotype used for the fusion experiments had a B. campestris cytoplasm. By analysis (it regenerated plants, line 25–143 was identified as possessing mt‐DNA recombined between B. campestris and B. tournefortii. with the major part derived from B. campestris. No differences were detected between epDNAs from H. campestris and from line 25—143. The other five lines were similar to B. campestris with all the probes used. The low frequency of sterile lines from the fusion experiments and the inheritance of the cms in segregating progenies are both discussed.
Genetic Analysis for Partial Resistance to an Iranian Strain of Bacterial Leaf Streak (X. campestris pv. hordei) in Barley
Authors: Alizadeh A. , Benetti V. , Sarrafi A. , Barrault G. , Albertini L. 
Published: April 2006

AbstractSeven barley genotypes with high genetic variability for resistance to bacterial leaf streak (Xanthomonas campestris pv. hordei) were crossed in diallel fashion to determine the inheritance of resistance to this disease. Two experiments were undertaken in a controlled growth chamber using a complete‐block design with four replicates. Each replicate consisted of a row of 20 seedlings per parent or F1 hybrid. An Iranian strain of bacterial leaf streak was used for inoculation of 12‐day‐old seedlings. Results showed that the cultivars ‘Express’ and ‘Morex’ and the Iranian pure line Iran‐3a had a high partial resistance in booth experiments. Diallel analysis showed highly significant general and specific combining abilities. ‘Morex’ and Iran‐3a were the best combiners for partial resistance to bacterial leaf streak in barley and could be successfully used for breeding purposes.
Yield Stability in Faba Bean, Vicia faba L. 1. Variation Among Inbred Lines*
Authors: Link W. , Stelling D. , Ebmeyer E. 
Published: April 2006

AbstractCultivation of faba beans (Vicia faba L.) is hampered by poor yield stability. The genetic variation at the homozygous level for yield stability in the gene pool of the small‐seeded and indeterminate European faba beans and the usefulness of auxiliary traits for the improvement of yield stability were investigated. The concept of stability, based on the regression technique, was applied. A sample of 36 faba bean lines was tested in 16 environments and a subsample of eight lines was tested in 11 additional environments. Significant differences were found between lines for yield stability parameters, but the repeatability of the results was limited. Early maturity correlated markedly (r = 0.51**) with one of the yield stability parameters (deviation from regression). Although lodging resistance was not correlated with the stability parameters, it proved to be a safety factor for performance.
An analysis of seed development in Pisum sativumL. XVI. Assessing variation for fatty‐acid content by use of a non‐destructive technique for single‐seed analysis
Authors: Jones D. A. , Barber L.M. , Arthur A. E. , Hedley C. L. 
Published: April 2006

AbstractAnalyses of seeds from a wide range of pea lines have revealed extensive variation for all of the major fatty acids normally found in pisum. Unlike total lipid content, this variation was not affected by the presence of mutant alleles at the r and rb loci. To allow chemically analysed seed to be used in crosses, which is of particular importance for F2 seed, a method has been developed by which individual seeds can be analysed non‐destructively. This system entails drilling a small hole in the seed, away from the embryonic axis. The small quantity of powder produced by this process can be used for the chemical analysis but does not prevent the seed from being grown to produce progeny. Reducing the sample size had no significant effect upon the compositional analysis of the fatty acids.
Prospects of breeding opium poppies (Papaver somniferum L.) as a high‐linoleic‐acid crop
Authors: Singh S. P. , Khanna K. R. , Shukla S. , Dixit B. S. , Banerji R. 
Published: April 2006

AbstractFatty‐acid composition was studied in a half diallel in opium poppies using six parents, F1 and F2. Poppy is an oleic‐linoleic‐acid type of crop with a low level of linolenic acid of up to 3% or only trace. Transgressive segregation was observed in F2 having up to 81% linoleic acid making it suitable for development as a high‐linoleic‐acid crop. This is the first report of its kind in opium poppy.
Genetic improvement in wheat yield and associated traits. A re‐examination of previous results and the latest trends
Authors: Calderini D. F. , Dreccer M. F. , Slafer G. A. 
Published: April 2006

AbstractTwo field experiments were carried out with seven wheat cultivars (three of them, including a commercial hybrid, released during the last 10 years) representing different eras of plant breeding, to evaluate genetic improvement over the last century in grain yield, height, biomass, harvest index and grain yield components. Plots were fertilized and irrigated, and lodging and diseases were prevented.Main culm height was negatively correlated with the year of release of the cultivars, probably as a consequence of selection for increased lodging resistance. There was no significant association between total above‐ground biomass and year of release of the cultivars. On the other hand, grain yield increased as newer cultivars were released. Results indicate that during recent years harvest index has been kept as the main attribute responsible for increases in grain yield. In general, number of grains/m2 was associated with increases in grain yield during the century. However, the newest cultivars showed an increased grain weight. In both growing seasons, cultivars released before 1980 showed a trend towards reduced grain weight, but cultivars released after 1987 had a similar number of grains per m2 with a higher grain weight than their predecessors. This was probably because the most modern cultivars have a longer grain‐filling duration with a similar length of growth cycle.
Mapping the GA3‐insensitive dwarfing gene ct1 on chromosome 7 in rye
Authors: Plaschke J. , Korzun V. , Koebner R.M.D. , Börner A. 
Published: April 2006

AbstractA gibberellic acid‐insensitive dwarfing gene in rye (ct1) was mapped in an F2 population on chromosome 7R close to the centromere. Two RFLP markers were found, which flank the gene at distances of 1 and 3 cM, respectively. A total of 11 markers were mapped on 7R of which six cluster around the centromere and show segregation distortion in the case of the codominant markers. The ct1 gene is closely linked to copies of both α‐amylase and EmBP, as is the ct2 gene on chromosome 5R. Because of the different chromosomal locations of the GA3‐insensitive dwarfing genes in rye and wheat it is concluded that these genes are not homoeologous. This is supported by further differences in their phenotypic and genotypic expressions.
Identification of powdery‐mildew‐resistance genes in common wheat (Triticum aestivum L.). VI. Wheat cultivars grown in China
Authors: Xia X. C. , Hsam S. L. K. , Stephan U. , Yang T. M. , Zeller F. J. 
Published: April 2006

AbstractA total of 26 common wheat cultivars and advanced breeding lines grown in China were tested with a set of 11 differential powdery‐mildew isolates. Seven cultivars were susceptible. Another seven cultivars showed the response pattern of resistance gene Pm2, either individually or in combination with genes Pm3d or Pm4a. Five cultivars expressed the resistance of gene Pm4b singly or in combination with Pm6. Another four cultivars exhibited the response patterns of genes Pm5, Pm6 and Pm8, respectively. Three cultivars, which included one breeding line with a pair of substituted chromosomes from Haynaldia villosa, presumably carrying the resistance gene Pm21, showed resistance‐response patterns to all the isolates tested.
Genetic analysis of resistance to leaf‐rust (Puccinia recondita f. sp. tritici) pathotypes in the durum wheats ‘PBW 34’ and ‘DWL 5023’
Authors: Gupta S. , Saini R. G. , Gupta A. K. 
Published: April 2006

AbstractGenetic analysis of leaf‐rust resistance was conducted on two durum wheats. Triticum durum cvs. ‘PBW 34’ and ‘DWL 5023’ were crossed with the leaf‐rust‐susceptible durum wheat ‘Malvi Local’. The F1, F2 and F3 generations were tested against leaf‐rust pathotypes 1, 77A and 108. In ‘PBW 34’, a single dominant gene was effective against each of the pathotypes 1 and 108, whereas two independently inherited dominant genes were effective against pathotype 77A. In ‘DWL 5023’, two independently inherited dominant genes were operative against pathotypes 1 and 77A, whereas a single dominant gene was identified as being operative against pathotype 108. Allelic tests on F2 generation and joint segregation analysis on F3 generation seedlings, suggested that two different genes in each cultivar are effective against these three leaf‐rust pathotypes. Cultivar ‘PBW 34’ has Lrd1 and Lrd2 genes whereas Lrd1 and Lrd3 genes are present in ‘DWL 5023’.