摘要:

AbstractMicrospore populations of eight Fhybrids of winter wheat (Triticum aestivum L.) whose parents had different levels of resistance toFusariumwere screened in vitro, using phytotoxins ofFusariumas biochemical probe. Two selection methods were compared for the in vitro selection: either embryoids and calli were first initiated from anthers in toxin‐free medium and then grown on medium with 0.3—0.9 %Fusariumtoxin; or anthers were immediately cultured in modified liquid potato‐2 medium in the presence of 1.5, 2.0 and 2.5mlFusariumtoxin per liter culture medium, a concentration which reduced the number of calli and embryoids to about 10 % compared to the toxin‐free controls. Microspores from donor hybrids which were produced from very susceptible cultivars were killed by lower toxin concentrations than micro‐spores from hybrids of less susceptible parents. From surviving calli and embryoids, originally initiated from 242,000 anthers in both procedures a total of 375 green lines could be regenerated. The results indicate that it is possible to enrich the fraction of regenerating microspores by those which contain the gene complex responsible for reduced susceptibility toFusariumby the use of a p

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01218.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractUtilization of the doubled haploid method of breeding usually shortens the time to cultivar release, and methods of haploid production need evaluation in a breeding programme. Thirty‐eight different three‐way crosses were tested for anther culture response. On average 5.8 percent of the anthers cultured produced calli. Three crosses were found recalcitrant for callus induction. Overall, the anther culture method produced 0.6 plantlet per 100 anthers cultured. Five crosses with an average of 5.8 and 2.8 percent of anthers producing calli and plantlets, respectively, were compared using anther culture and wheat × maize crosses. Non‐responsive genotypes for callus induction and plantlet formation in the anther culture method proved to be good parental material in wheat × maize crosses. The average percentages of embryo formation and plantlet production in wheat × maize crosses were 10.3 and 4.7, respectively. Anther‐derived plants were cytologically unstable, whereas all the plants regenerated from wheat × maize crosses were haploids (n = 21 chromosomes). The chromosome numbers of the polyhaploids were doubled with a colchicine treatment. Improvement of the two haploid production methods to facilitate their efficient use in a breeding programme i

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01219.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractSynthetic hexaploid wheat, produced by combining tetraploid wheat (AB genome) withTriticum tauschii(D genome), was crossed to modern hexaploid wheat (Triticum aestivumABD genome) in an attempt to introduce new cold hardiness genes into the common hexaploid wheat gene pool. The cold hardiness levels of F) hybrids ranged from similar to parental means to equal to the hardy parent, indicating that cold hardiness was controlled by both additive and dominant genes. As expected when dominant gene action is involved, differences between F2and parental means were smaller than comparable differences in the F., Frequency distributions of F2—derived F3lines also suggested that dominant genes were involved in the control of cold hardiness in some crosses. Heritability estimates for cold hardiness ranged from 63 to 70 % indicating that selection for cold hardiness should be effective in populations arising from crosses between common and synthetic hexaploid wheat. However, high selection pressure on the progeny of crosses that included the most hardyT. aestivum, T. durum, andT. tauschiiaccessions as parents did not identify transgressive segregates for improved cold hardiness. These observations indicate that the close wheat relatives, sharing common genomes withT. aestivum, are not promising sources of new genes to increase the maximum cold hardiness potential of common hexaploid whea

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01220.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe production of homozygous doubled haploids via anther culture was investigated in the self‐incompatible diploid speciesHordeum bulbosum.Anthers from three accessions (GBC77, GBC752 and GBC753) were cultured on FHG media using IAA or three levels (1, 50 and 100 mg/l) of the auxin phenylacetic acid (PAA). Four green plants and 63 albino plants were obtained from a total of 1620 plated anthers (540/accession). The best mean anther response, number of embryogenic calli and regenerated plants were obtained with 50 mg/1 PAA. Three of the four green plants survived to maturity and, based on root‐tip squashes stained with feulgen, all had 14 chromosomes like the anther donor parent. These anther culture‐derived plants contained only some of the parental DNA bands, as observed by PCR analysis, indicating that they are of gametic origin rather than arising from somatic parental tissue. This is the first report of homozygous lines produced from this self‐incompatible

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01221.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractGenetical studies have been conducted with lines derived fromH. spontaneumshowing that these lines carry dominant mildew resistance genes located at or near theMla, locus. The resistance spectra of the lines ‘RS170—10 × Piccolo A’, ‘Diamant × 1B‐20’, ‘RS1—8 × Piccolo E’ and ‘Diamant × 1B‐151’ obtained from 10 European and Israeli isolates differ from previously‐identified Mia alleles. Therefore, it is suggested that these genes should be designated asMla25,Mla26,Mla.27 andMla28, respectively. In addition, the RFLP‐patterns of these lines and their crossing parents were studied by hybridization with probes MWG 1H036, MWG 1H060 and MWG 1H068, which are very closely linked to the Mia locus. Two double crossover events have been identified. The use of RFLP markers for the identification of milde

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01222.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractCrosses were made between 14 wheat genotypes (11 tetraploid, 3 hexaploid) and a single Fl hybrid of maize that was used as the male parent. The experimental design consisted of randomized blocks with three replications. Plants were grown under controlled greenhouse conditions (day length 16 h and temperature 25 °C/15 °C, day/night). To enhance embryo survival, 2, 4‐D treatment (10 mg/1) was applied to spikes 24 h after pollination with maize. Embryos were recovered from all tetraploid and hexaploid wheats at a rate of 2.09 to 26.76 per 100 pollinated florets. Haploid and doubled haploid plants were obtained from all hexaploid genotypes (T. aestivum) and from 5 of 11 tetraploid genotypes (T. turgidumvar.). The most important point of these experiments was the ability to produce haploid plants from tetraploid wheat for two reasons: firstly, anther culture cannot be applied in tetraploid wheat (T. turgidumvar.) due to the inefficiency of embryo formation and the high proportion of albino plants. Secondly, to date, crosses between tetraploid wheat and maize have resulted in embryo formation, but not in haploid pla

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01223.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractTwo Cultivars Of Bread Wheat (Triticum AestivumL.) Showing Significant Differences In Stomatal Frequency On The Adaxial Surface Of The Flag Leaf Blade, Were Hybridized. Transgressive Segregation For Stomatal Frequency Was Observed In The F2Generation and Selections Were Made For High and Low Stomatal Frequency. In The F9Generation Two Selections Had Significantly Higher Frequencies Than The Higher Parent. Heritability For Stomatal Frequency Based On Parent‐Progeny Regression Were 42 % (F3—F4) and 81 % (F4—F5). Stomatal Frequency Was Negatively Correlated With The Flag Leaf Blade Area, Mesophyll Cell Size and Grain Size, However, Exceptions Were Obs

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01224.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA simple and inexpensive method for the estimation of total glucosinolate (GSL) Content In rapeseed is described. It employs a newly developed portable reflectance instrument, the TRUBLUGLU Meter. The assay is based on the selective hydrolysis of Gsls By Endogenous myrosinase at pH 9, followed by measurement of the released glucose using Clinistix strips. The meter, which is calibrated prior to use with a standard glucose solution, can display a digital readout in units of either mM glucose or μol Gsl/g Seed

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01225.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractNut samples of hazelnut (Corylus avellanaL.) cultivars, selections, and seedlings were cracked and scored for frequency of good kernels and 7 types of defects. Blanks, poorly filled nuts, and moldy kernels were the most common defects. Variance components were calculated using defect counts from trees of 17 genotypes which were sampled in each of 4 years. The largest components were for among genotypes, genotype × year interaction, and between samples within trees. Year effects were large only for poorly filled nuts. The genotype × year interaction term was large for black tips, shrivels, and blanks. Variance components indicate limited genetic variability for brown stain, but moderate to large amounts for all other defects. Narrow sense heritability estimates from regression of progeny means on mid‐parent values exceeded 50 % for frequency of blanks (51 %), moldy kernels (61 %), kernels with black tips (60 %), and doubles (84 %), but was low for frequency of shrivelled kernels (22 %), poorly filled nuts (25 %), and brown stain (15 %). The low heritability of poorly filled nuts appears to indicate that the frequency of poor fill in the first crop or two produced by a young seedling does not reliably predict the genotype's susceptibility to this disorder rather than a lack of additive genetic variance. Heritability was intermediate for frequency of good kernels (42 %). Phenotypic correlation coefficients indicate that nut weight, kernel percentage, fiber rating, and pellicle removal rating are, for applied breeding purposes, inherited independently of the frequency of the 7 types of defe

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01226.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractA set of 21 monosomics of ‘Chinese Spring’ was used to locate the rust resistance genes of Tengkang 2′, developed by the Chinese Academy of Agricultural Sciences. The resistance to yellow rust race CY25 was controlled by a dominant gene located on chromosome 5B and resistance to leaf rust race CL38 was controlled by a dominant gene located on chromosome 5A in ‘Tengkang 2’. Most likely these two gene

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1993.tb01227.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY