摘要:

AbstractCarrot breeding in the past 150 years has resulted in varieties with high yield, a short growing period, and excellent root colour. Recently, hybrid varieties have demonstrated good uniformity of roots, a quality accepted by most consumers. By contrast, only a few resistant varieties (mainly open‐pollinated varieties) are offered by seed companies, most being resistant toAlternaria.Hybrid breeding offers a chance of combining good uniformity and different sources of resistance. Efforts in future breeding should concentrate on the improvement of health and the development of genotypes suitable for cultivation in suboptimal climates and regions, as well as for special application

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00750.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractHinfl ‐digested DNA samples of wild and cultivated species of tomato were hybridized in gel to different oligonucleotide probes complementary to simple‐sequence repeats. All motifs tested i.e. (GATA)4, (GGAT)4, (CA)8. (CAG)5, (GTG)5, (GAAGTGGG)2and (CCTA)4, produced multilocus fingerprints in all tomato species and cultivars. The extent of inter‐ and intraspecific polymorphism of the banding patterns varied considerably between different probes, with (GGAT)4, (CCTA)4, (GATA)4and (CA)8showing a much higher discriminatory potential than the other probes. Cluster analysis of band‐sharing data yielded dendrograms which were consistent with the known history of tomato cultivation. (GATA)4was also successfully used for purity testing of breeding lines, as well as for analysing an F1progeny of a cross between tw

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00751.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractIn order to develop fully inbred chicory plants, dihaploid plants were raised from callus derived from microspores of three selected Witloof, Robin and Treviso types. Microspores were isolated from florets containing pollen at the uninuclear state and cultured in a modified MS medium plus 0.5mg/l 2,4‐D, 0.5mg/l IAA and 2.0mg/l zeatin. During culture periods of up to 6 months, gametoplasts emerged from pollen grains, divided and started to form colonies and calli. These were subcultured on the same basal medium supplemented with 0.5mg/l BA and 0.5mg/l IAA. Shoot growth was enhanced on a low salt‐containing medium supplemented with 0.4mg/l kinetin and 0.2mg/l IAA. Shoots were rooted on a half‐strength Lepoivre medium plus 0.2mg/l IBA and finally transferred to soil. Florets were excised from 34 capitula, but only microspores from four of them developed into plants via callus. More than 450 plants were raised in the greenhouse and the field. Leaves from these plants were subjected to DNA fluorescence analysis via flow cytometry: a range of ploidy levels was detected. The cell composition of 44 of these plants was predominantly haploid, with a diploid background. Regenerant plant phenotypes were compared with the parent genotypes. The value of such haploids in commercial chicory breeding is disc

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00752.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe aim of this study was to test whether the null alleleEp‐D1cof the endopeptidaseEp‐D1can be used as a marker for theLrl9leaf rust resistance gene. The frequency ofEp‐D1cwas determined in 1134 winter wheat, spring wheat and spelt breeding lines and varieties. Only eight lines were found to carryEp‐D1c.Six of these lines originated from crosses with RL6040, the gene donor for Lrl9. The other two lines were leaf‐rust susceptible in the seedling stage and therefore did not carryLr19.The genetic distance betweenEp‐D1candLr19was determined in a reciprocal cross between the lines FAP75184 (Ep‐D1c, Lr19) and FAP75106 (Ep‐D1a, leaf‐rust susceptible in the seedling stage). Out of 840 F2seedlings screened, 162 were homozygous forEp‐D1c.From 150 of these F2plants, F3seedlings were screened for segregation for leaf‐rust resistance with isolates avirulent onLr19.Only one F2plant produced susceptible F3progeny indicating a recombination event betweenEp‐D1candLr19.From these data, a genetic distance of 0.33 ± 0.33cM betweenEp‐D1candLr19was calculated. The results show thatEp‐D1cis a useful marker for a practical breeding programme allowing the rapid identification

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00753.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA total of 59 old wheat cultivars grown in Germany prior to 1960 were tested for mildew response using a collection of 12 differential isolates ofErysiphe graminisDC f. sp.triticiMarchal (Blumeria graminis(DC) Speer f. sp.tritici). Nineteen cultivars did not possess any major resistance gene and 25 were characterized by susceptible or intermediate responses. Fifteen cultivars revealed isolate‐specific response patterns that could not be attributed to known major resistance genes or gene combinations. Many of the old German cultivars inherited a mildew‐resistance gene from the Canadian cultivar ‘Garnet’ which is tentatively designatedM1‐Ga.Cultivars ‘Bretonischer Bartweizen’ (designatedM1‐Br) and ‘Adlungs Alemannen’ (designatedM1‐Ad) appeared to carry unknown resistance genes.Among 18 winter wheat cultivars released in the former GDR. eight showed susceptibility to all isolates used. Cv. “Borenos” carries resistance genePm3c.Five cultivars possess gene Pm4b. two cultivars genepm5and one cultivar a combination of genesPm2andPm4b.Cultivar ‘Zentos’ was resistant to almost all isolates used. Its resistance might be conditioned by different u

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00754.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractSets of D‐genome disomic substitution lines of ‘Langdon’ (Triticum turgidumvar.durum) were used to study the effect of chromosome substitutions on grain yield and flour technological properties.In general, the substitution of any D‐genome chromosome had a detrimental effect on grain yield and growth vigour (some lines were sterile). SDS‐sedimentation, SE‐HPLC and two‐gram mixograph procedures were used to measure dough strength of the lines studied. Significant correlations were observed between protein concentration and grain yield and other quality parameters such as SDS‐sedimentation value, the proportion of glutenin, dough mix time and peak resistance. Most of the quality characters were highly correlated with each other.Substitution of chromosomes 1D, 5D, 2D and 7D resulted in positive responses to SDS‐sedimentation values, but only chromosome 1D had positive effects on the proportion of peak 1 (P1%), measured by SE‐HPLC. Besides the major influence of chromosome 1D on three major mixograph parameters (mixing time, peak resistance and resistance breakdown), chromosome 5D also exhibited significant effects on these mixing parameters. Principal‐component analysis showed that the predominant effect on durum‐wheat rheological properties was from chromosome 1D, whereas chromosome 5D had a major effect on grain hardness (50%) and increased the

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00755.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe objective of this paper was to study the differences between some prolamin variants coded at the lociGlu‐3/Gli‐1,Glu‐1 andGli‐A2 and their relative roles in durum‐wheat quality. F3lines from four durum wheat crosses (‘Abadia’בMexicali’. ‘Oscar’בArdente’, ‘Oscar × Mexicali’ and ‘Alaga’בC. of Balazote’) were analysed for gliadin and glutenin composition by electrophoresis. Whole‐grain‐derived samples were analysed for SDS sedimentation (SDSS) value, mixing properties, and contents of protein and vitreousness. The glutenin patterns LMW‐2. LMW‐2−and LMW‐2 (CB) atGlu‐B3/Gli‐B1 were associated with better gluten quality than were LMW‐1 and LMW‐2*. The glutenin subunits LMW4 and LMW3 + 15 atGlu‐A3/Gli‐A1 and HMW‐1 showed better mixing properties than LMW7 + 12, LMW5 and the null phenotype. respectively. The HMW glutenin subunits 20 + 8 atGlu‐B1 showed a negative association with gluten quality, but the rest of the HMW glutenin subunits and α‐gliadins did not show any influence on gluten quality.Correlations between the results of the SDSS test and the mixograph were highly significant, but no correlation was found between these results and protein and vitreousness contents. The results are discussed in rela

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00756.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractDrought stress is the main factor limiting barley yields in West Asia and North Africa. This study compares the utility of doubled haploid lines (DHLs) and conventional F2plant‐derived bulks (F2Bs) in improving barley in stress environments. Double crosses were made, DHLs were developed by anther culture from double‐cross F1plants, and F2Bs were produced by bulking the offspring of F2plants. Field tests were conducted in three drought‐stressed environments. No major differences were observed in the mean performance of DHLs and F2Bs. For most traits, both the genotypic and the genotype × location interaction variances were higher in the DHL group, whereas heritabilities were similar. Higher gains from selection were predicted for the DHL group. Regression analysis of yield stability indicated a lower predictability of the DHL performance. The haploid technique can improve breeding populations from which varieties with stable yields can be developed. The costs involved are determined by the DHL production rate, which needs to be improved in many developing cou

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00757.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe barley accession Q21861 possesses resistance to the stem‐rust (Puccinia graminisf.sp.tritici), leaf‐rust (P. hordei), and powdery‐mildew (Blumeria graminisf.sp.hordei) pathogens. An anther‐culture‐derived doubled‐haploid population was produced from F1plants from a cross of this accession and the susceptible breeding line SM89010 as a means of rapidly and efficiently determining the genetics of multiple disease resistance. The doubled‐haploid population segregated 1:1 (resistant:susceptible) for resistance to the stem rust pathotype QCC indicating the involvement of a single resistance gene, rpg4. Two‐gene (3:1) and one‐gene (1:1) segregation ratios were observed for resistance to the stem‐rust pathotype MCC at low (23–25°c) and high (27–29°C) temperature, respectively. These different segregation patterns were due to a pathotype × temperature interaction exhibited byrpg4andRpg1.another stem‐rust‐resistance gene present in Q21861. One‐gene and two‐gene segregation ratios were observed in reaction to the leaf rust and powdery mildew pathogens. These data demonstrate the utility of doubled haploid populations for determining the genetics of mul

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00758.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractHill plots offer advantages in testing large germplasm arrays with limited area and seed. However, the relationship of trait expression between hill vs. row plots remains in question. The development of quantitative‐trait‐locus (QTL) analysis offers alternative methods of testing hypotheses regarding levels of coincident gene effects in divergent plots. The objective of this study was to compare hill and row plots in terms of QTL detection, number of common QTLs and plot‐type‐specific QTLs for various characters in barley. Assessments were based on sets of 100 F1‐derived doubled haploid progeny from two environments of hill‐plot data and two sets of multiple‐environment row‐plot data. Common large‐effect QTLs for height, heading date, and 1000‐kernel weight were detected in both plot types. Fewer QTLs were detected in the hill‐plot data, with only one QTL detected for grain yield. There were no hill‐plot‐specific QTL effects. Hill plots appear to be best suited to highly heritable characters such as height, heading date, and 1000‐kernel weight. Evaluation of grain yield is best deferred until larger experim

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1995.tb00759.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY