摘要:

AbstractThe possible applications of genie male sterility (GMS) in plant breeding arc reviewed and discussed. The basic contribution of GMS is that it provides a means of genetic emasculation which can be applied for the massive production of hybrids. There are two main fields of application: (1) the production of hybrid varieties and (2) inter‐ and intraspecific hybridization and back‐crossing programmes for the introduction of genetic variation into crop varieties. Several schemes have been proposed for using GMS in hybrid breeding in different crops. These are discussed under four headings: genetic methods, cy‐togenetic methods, temporary restoration of fertility and manual pollination. The application of GMS in hybridization intended for the introduction of alien genes is discussed as well as factors affecting the pollination of genie male ste

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00447.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractPlant maturity descriptors are important for many forage breeding decisions and in forage production research. The objectives of this study were to evaluate the effects of genotypes, maturity rating scale, maturity rating unit, and observer on visual evaluations of maturity inDactylis glomerata.Tetraploid clonal material was planted at three locations in Wisconsin in August of 1986. All plants were rated for maturity in early June 1987; locations were rated within 3 days of each other. For most family‐location combinations, parents were more advanced in maturity than offspring family means. Family maturity could not be predicted from mean parent maturity scores. Genotype × location was the only significant interaction. On the average, the single digit rating scale led to an earlier assigned maturity value than the two‐digit scale. The discrepancy between the rating scales was dependent on location. High phenotypic correlations between rating units and between rating scales suggested that ratings can be done on a whole‐plant basis using either scale. However, if maturity is used as a covariate for another trait, a two‐digit scale is p

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00448.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe glucosinolate (GSL) pattern of 93 resynthesized (resyn) repeseed lines was examined over three years, and five stable genotypes with distinct GSL profiles were identified. Typically the resynB. napusprofile exhibited progoitrin as the main GSL, but contained sinigrin. The different GSL patterns of the four deviating lines are discussed with respect to the proposed biosynthetic pathway. Within the resyn and further extensive breeding materias, screening for low indolyl GSL contents resulted in finding one genotype with an extremely low 4‐hydroxy‐gluco‐brassicin and glucobrassicin content. Furthermore, other lines were identified, over a wide range of indolyl GSL contents. The values were stable over two

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00449.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIn anther culture experiments with four German spring wheat cultivars (‘Turbo’, ‘Kadett’, ‘Planet’ and ‘Nandu’), ‘Nandu’ showed the best results. The rate of responding anthers with ‘Nandu’ was 0.8 % on medium N6 and 3.7% on potato‐2. This was similar to the Chinese cultivar ‘Orofen’. Higher yields of embryoids could be obtained with medium potato‐2 than with N6.Experiments with medium potato‐2 showed that anther response, production of embryos and regeneration increased with decreasing agarose concentration.Regeneration of green plantlets was improved by differentiation in the dark whereas differentiation under light yie

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00450.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractDifferent wheat genotypes were treated with gamma‐rays, sodium azide (SA) and EMS before tissue culture and immature embryos from M1plants or plants shortly after exposure to gamma‐rays were used to initiate callus culture. Thousands of plants were regenerated and used to investigate the effect of mutagenic treatments on the regenerated plants and somaclonal variation in the M3R2and M2R2generations. The results showed that mutagen‐induced damage in terms of reduction in plant height, fertility and spike length were not outstanding in the regenerated plants as compared with the untreated control. In the M3R2generation, only SA treatment had significantly higher frequencies of somaclonal variations than the control. Increases in the variation frequencies were observed when explant embryos were irradiated with 2.5 and 5 gy gamma‐rays and the highest frequency appeared when embryos were exposed to 5 gy gamma‐rays on the 5th day after anthesis. Increased variation spectra also resulted from mutagenic treatments and most of the variants recovered were unsuitable for plant im

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00451.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA yield‐based assessment procedure for breeding for resistance toSeptoria nodorum(SN) is presented. Artificially infected as well as fungicide‐protected plots were analyzed for each genotype. Considerable increase in precision of disease scores was gained by using an assessment matrix for different plant organs and time intervals during disease development. This technique resulted in yield loss: disease attack correlations up to r = 0.85:** and raised coefficients of heritability (h2b= broad sense heritability) with h2b= 0.72 for % yield loss and h2b= 0.86 for SN‐attack, calculated for a 3‐year replicated field experiment with 105 winter wheat cu

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00452.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe protection provided by the leaf rust resistance geneLr34againstPuccinia reconditaf. sp.triticiwas studied in the field over two seasons. In leaf‐rust inoculated and fungicide‐sprayed control plots, yield of RL6058, the ‘Thatcher’ backcross line withLr34, was compared to that of the susceptible cultivar ‘Thatcher’. Leaf rust severity remained low on RL6058 in both seasons, but was high on ‘Thatcher’. The latent period of wheat leaf rust isolate 3SA132 in flag leaves of RL6058 was 256 h longer than in ‘Thatcher’. The uredinium density on ‘Thatcher’ was 14.4/cm2, compared to 3.7/cm2flag leaf surface on RL6058. Leaf rust infection of ‘Thatcher’ reduced the total grain yield per plot by 25.4% and 1,000 kernel mass by 15.6%. Leaf rust caused little or no damage on RL6058 and rusted plots outyielded the control plots by 0.3 %. Seed weight of RL6058 was reduced by 0.7%. Compared to previous greenhouse studies, the adult‐plant resistance conferred byLr34is more clearly expressed in the field. Evaluation of milling and baking quality characteristics revealed that compared to ‘Thatcher’, RL6058 had a higher flour protein content, but that its milling, dough development an

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00453.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractF1, F2, Fl × parentl (BC1), and Fl × parent2 (BC2) generations resulting from four crosses among seven cultivars of barley used in national and international breeding programmes were tested at the seedling stage for their resistance to a mixture of five isolates ofPyrenophora teres.Four methods were used to assess disease resistance: infection type (IT), average lesion size (ALS), number of lesions per unit leaf area (NL) and percent leaf area infected (PLAI). Gene actions were estimated by generation mean analysis on each of the four crosses and on each of the evaluation methods. Significant additive and additive × additive epistatic effects were found. Infection type and percent leaf area infected were found to be highly correlated in all four crosses. These results suggest that barley breeders could improve the level of resistance toP. teresby making appropriate crosses between highly susceptible barley cultiva

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00454.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThirty‐one accessions of four Lactuca species (L. serriola, L. saligna, L. aculeata, L. squarrosa) and oneL. serriola×L. sativahybrid were screened for field resistance toBremia lactucae.In theL. serriolagroup, significant differences in the level of field resistance were distinguished. The accessions PI 281876 and PI 253467 were free of infection. Moreover, allL. salignaaccessions tested were totally free from disease during three‐year‐investi

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00455.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractRey‐cytoplasmic rye‐wheat‐additioons were analysed for catalase structural genes using polyacrylamide gel electrophoresis. A structural gene of wheat was found to be located on chromosome 4b and on telocentric 4bL, respect

ISSN:0179-9541    

DOI:10.1111/j.1439-0523.1990.tb00456.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY