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1.
Clubroot, caused by Plasmodiophora brassicae Woron, is a major disease of cruciferous crops and few sources of resistance have been detected and genetically studied in the Brassica oleracea species. In this study, two diallel mating systems using resistant kale lines and susceptible cauliflower lines were performed. Resistance was assessed from a disease index evaluated on young plants artificially inoculated with local isolates of the parasite. Both general and specific combining ability effects (GCA and SCA) and partly reciprocal effects were demonstrated. Resistance inheritance was, however, characterized by a predominance of additive genetic effects (GCA). Three groups of parent lines could be separated; kale lines with very high resistance, kale lines with intermediate resistance and susceptible cauliflower lines. In the two kale groups, two genetically different resistance types were suggested and various recurrent selection procedures are proposed following the diallel results. 相似文献
2.
First steps towards a rational use of African rice, Oryza glaberrima, in rice breeding through a ‘contig line’ concept 总被引:1,自引:0,他引:1
The inheritance of resistance to clubroot, caused by Plasmodiophora brassicae, in Brassica oleracea was studied in the F1, F2and backcross progenies of four crosses between resistant and susceptible doubled haploid lines. The disease severity was scored visually on a 0–3 scale of symptom grades. These were analyzed qualitatively and quantitatively. The qualitative analysis involved the conversion of symptom grades to a classification as resistant or susceptible, and segregation ratios were used to test several simple genetic models. The quantitative analysis was based on a threshold model, in which symptom grades are considered to arise from splitting a continuous response range into disjoint intervals. This analysis was based on the maximum likelihood method, and several genetic models were evaluated.Of the four resistances studied, one was shown to be largely determined by two complementary genes. Two other resistances were also shown to be probably controlled by two genes, but the mode of inheritance was not determined unambiguously. The fourth resistance appeared to be determined by more than two genes. 相似文献
3.
Katsunori Hatakeyama Shota Yuzawa Kaoru Tonosaki Yoshihito Takahata Satoru Matsumoto 《Breeding Science》2022,72(2):115
Clubroot resistance (CR) is an important trait in Chinese cabbage breeding worldwide. Although Crr1a, the gene responsible for clubroot-resistance, has been cloned and shown to encode the NLR protein, its allelic variation and molecular function remain unknown. Here, we investigated the sequence variation and function of three Crr1a alleles cloned from six CR F1 cultivars of Chinese cabbage. Gain-of-function analysis revealed that Crr1aKinami90_a isolated from the cv. ‘Kinami 90’ conferred clubroot resistance as observed for Crr1aG004. Because two susceptible alleles commonly lacked 172 amino acids in the C-terminal region, we investigated clubroot resistance in transgenic Arabidopsis harboring the chimeric Crr1a, in which 172 amino acids of the functional alleles were fused to the susceptible alleles. The fusion of the C-terminal region to the susceptible alleles restored resistance, indicating that their susceptibility was caused by the lack of the C-terminus. We developed DNA markers to detect the two functional Crr1a alleles, and demonstrated that the functional Crr1a alleles were frequently found in European fodder turnips, whereas they were rarely introduced into Japanese CR cultivars of Chinese cabbage. These results would contribute to CR breeding via marker-assisted selection and help our understanding of the molecular mechanisms underlying clubroot resistance. 相似文献
4.
Roeland E. Voorrips 《Euphytica》1995,83(2):139-146
Summary Clubroot is one of the most damaging diseases inBrassica oleracea crops world-wide. The pathogenicity ofPlasmodiophora brassicae is highly variable between as well as within field populations. Several sources of resistance to clubroot have been identified inB. oleracea. Generally, resistance tends to inherit partly as a recessive, partly as an additive trait, and appears to be controlled by few major genes. Progress in the understanding of the inheritance of resistance is being made through the use of single-spore isolates of the pathogen, and the use of molecular markers for resistance genes.Abbreviations cv
cultivar
- DH
doubled haploid
- ECD
European Clubroot Differential set
- RFLP
Restriction Fragment Length Polymorphism 相似文献
5.
Summary Interspecific hybridization between Brassica napus L. (2n=38, a1a1c1c1) and B. oleracea var. capitata L. (2x- and 4x-cabbage; 2n=2x=18, cc and 2n=4x=36, cccc) was carried out for the purpose of transferring clubroot disease resistance from the amphidiploid species to cabbage. Nineteen hybrids with three different chromosome levels (2n=28, a1c1c; 2n=37, a1c1cc and 2n=55, a1c1cccc) were obtained. The F1 plants were mostly intermediate between the two parents but as the number of c genomes in the hybrids increased, the more closely the hybrids resembled the cabbage parent. All F1 hybrids were resistant when tested against race 2 of Plasmodiophora brassicae
wor. The complete dominance of resistance over susceptibility suggested that the gene(s) controlling resistance to this particular race of the clubroot pathogen is probably located on a chromosome of the a genome in Brassica.Contribution No. J654. 相似文献
6.
Takeyuki Kato Katsunori Hatakeyama Nobuko Fukino Satoru Matsumoto 《Breeding Science》2012,62(3):282-287
In Chinese cabbage (Brassica rapa), the clubroot resistance (CR) genes Crr1 and Crr2 are effective against the mild Plasmodiophora brassicae isolate Ano-01 and the more virulent isolate Wakayama-01, but not against isolate No. 14, classified into pathotype group 3. ‘Akiriso’, a clubroot-resistant F1 cultivar, showed resistance to isolate No. 14. To increase the durability of resistance, we attempted to identify the CR locus in ‘Akiriso’. CR in ‘Akiriso’ segregated as a single dominant gene and was linked to several molecular markers that were also linked to CRb, a CR locus from cultivar ‘CR Shinki’. We developed additional markers around CRb and constructed partial genetic maps of this region in ‘Akiriso’ and ‘CR Shinki’. The positions and order of markers in the genetic maps of the two cultivars were very similar. The segregation ratios for resistance to isolate No. 14 in F2 populations derived from each of the two cultivars were also very similar. These results suggest that the CR locus in ‘Akiriso’ is CRb or a tightly linked locus. The newly developed markers in this study were more closely linked to CRb than previously reported markers and will be useful for marker-assisted selection of CRb in Chinese cabbage breeding. 相似文献
7.
Summary The first backcross and F2 progenies from triploid F1 and tetraploid F1 hybrids between B. napus and 2x and 4x B. oleracea ssp. capitata (cabbage) were studied for their general morphology, resistance to race 2 of the clubroot pathogen, chromosome number and meiotic chromosome behavior. No linkage was apparent between resistance and the major morphological characters. Unreduced gametes played a large part in the successful formation of seed of the B1 and F2 progeny. B1 plants with low chromosome numbers were selected for use in recurrent backcrosses. The potential use of anther culture to extract gametic progenies from resistant B1 and F2 plants with higher chromosome numbers was suggested. The presence of homoeologous pairing observed in all the plants is considered advantageous for selecting suitable progeny in later generations. 相似文献
8.
Summary Meiosis in 14 interspecific F1 hybrids with three chromosomal levels (triploid, tetraploid, hexaploid; 2n=28, 37 and 55) between Brassica napus L. and 2x and 4x cabbage (B. oleracea var. capitata L.) was studied. The oleracea genome from B. napus maintained close homology with the c genome of cabbage while the campestris genome of B. napus showed partial homology with the c genome contained in the hybrids. Genotypic influence on chromosome pairing was indicated. Structural chromosome differences and spontaneous chromosome breakage and reunion were suggested as causes for the abnormalities which related to the unbalance of the genotypes. The divergence of the genomes of B. napus and B. oleracea and the need for the qualification of the term secondary association were discussed.Contribution No. J. 673, Research Station, Agriculture Canada, St. Jean, Québec. 相似文献
9.
Summary The inheritance of resistance in cabbage (Brassica oleracea var.capitata) to damage caused byThrips tabaci Lindeman was studied in progeny from four crosses between resistant and susceptible inbred lines. In two families sharing the same susceptible parent, the narrow-sense heritability was calculated to be high (>90%), using the Warner method of calculation (Warner, 1952). The other two families, also sharing a susceptible parent, had very low narrow-sense heritability (0–11%). In three of the four families, however, the validity of the Warner calculations were called into question due to significant epistatic interactions. In all four families, the F1 populations approached or exceeded the susceptibility of the susceptible parent, indicating that susceptibility is generally dominant. The importance of epistasis and dominance suggests that tests of hybrid combinations to determine combining ability for thrips resistance may be required, rather than selecting only on the basis of thrips damage to the inbred lines. The technique of planting wheat upwind from the cabbage test plot did generate adequate levels of thrips pressure, but the infestation was uneven in two of the four blocks, so that reasonable replication of tests is required. 相似文献
10.
Summary The somatic karyotype and meiotic chromosome behavior were studied in an 18-chromosome B1 plant derived from backcrossing a triploid (Brassica napus x B. oleracea ssp. capitata) F1 hybrid to cabbage. It is considered that cabbage chromosomes no. 1 and no. 7 were substituted by two shorter B. napus chromosomes. Meiotic disturbances were more apparent during the late stages of second division. Seed fertility of this plant was largely restored in the second backcrosses with both cabbage and broccoli. 18-chromosome B2 plants resistant to race 2 of Plasmodiophora brassicae were recovered among the progenies.Contribution no. J. 725 from the Research Station, Research Branch, Agriculture Canada, St-Jean, Québec J3B 6Z8. 相似文献