@article{oai:repository.naro.go.jp:00001465,
 author = {八木, 雅史 and YAGI, Masafumi},
 journal = {花き研究所研究報告, Bulletin of the National Institute of Floricultural Science},
 month = {Dec},
 note = {This study was carried out to utilize DNA markers in carnation (Dianthus caryophyllus L.) breeding and to clarify the genetic basis such as the ploidy level and genetic diversity of carnation cultivars. 1. Construction of genetic linkage map, quantitative trait locus (QTL) analysis and application to breeding in carnation To improve the selection efficiency in carnation breeding for resistance to bacterial wilt caused by Burkholderia caryophylli, the first genetic linkage map for the carnation was constructed by using a resistance-segregating population of 134 progeny lines derived from a cross between 'Carnation Nou No.1' (a line resistant to bacterial wilt) and 'Pretty Favvare' (a susceptible cultivar) based on RAPD and SSR analysis. The linkage map contained 137 RAPD and 9 SSR markers. Linkage analysis revealed that 124 loci could be mapped to 16 linkage groups that extended for 605.0 cM. The average interval between two loci was 4.9 cM. QTL analysis was applied to replication 8 evaluations of resistance to bacterial wilt. A QTL with a large resistance effect was detected on Group 6, which accounted for 60.5% of the total phenotypic variance with an LOD score of 23.46. Two other QTL with a small effect were detected on Groups 2 and 5 with LOD scores of 2.32 and 2.87, respectively. These results suggest that resistance to bacterial wilt in carnation is related to one major and at least two minor genes. The availability of marker-assisted selection (MAS) using DNA markers close to the QTL of resistance to bacterial wilt in carnation was examined. The STS-WG44 marker tightly linked to the major resistance gene was detected in all backcross lines with resistance selected by the root-soaking method. The ratio of markers OQ12 and STS-WB66 close to the two QTL with a small effect in resistant lines was lower in succeeding generations of backcrossing. These findings suggest that STS-WG44 is available for selecting resistant lines. In practical breeding populations, the difference in mean disease incidence between two groups categorized as having or lacking STS-WG44 was 62.6% and STS-WG44 was present in most lines showing disease incidence of less than 20%. These findings suggest that STS-WG44 as a selective marker facilitated the narrowing of populations to those that are highly resistant for practical breeding. MAS would be available for breeding improved resistance to bacterial wilt in carnation. Flower color is an important trait in ornamental plants. To understand the genetic basis for anthocyanin pigmentation traits in the flower petals of carnation, the segregation of anthocyanin content in petals was evaluated and QTL analysis was conducted by using the linkage map constructed in this study. The frequency of low anthocyanin content (<0.5 mg/g FW.) was highest and the frequency decreased in inverse proportion to anthocyanin content. QTL analysis identified two QTL on linkage Groups 6 and 9, which accounted for 21.6% and 15.0% of the total phenotypic variance, with LOD scores of 6.33 and 4.15, respectively. 2. Identification of ploidy level and cultivar diversity by flow cytometry (FCM) and SSR markers FCM was conducted to estimate the polyploidy level of 304 cut and 45 potted carnation cultivars preserved at the National Institute of Floricultural Science. To verify the actual level, the chromosome count in the root tips was investigated. In the cut carnation cultivars, an estimated 297 cultivars were diploid. Three cultivars ('Wiko', 'Scarlet Bell', and 'Spiral Vivid Red') were triploid and 'Saleya' was tetraploid. Another three cultivars ('Pink Roland', 'Youkihi', and 'Sonnet Sailor') were possibly tetraploid. In the 45 potted carnation cultivars, the results strongly suggested that 27 cultivars were diploid, three were triploid, and 15 were tetraploid. The chromosome count in the root tips revealed that 'Camille' was diploid, 'Baby Heart' was triploid, and 'Tula' was tetraploid. Our results suggest that the ploidy level varies among potted carnation cultivars. The stomatal length of 12 cut and 10 potted carnation cultivars was measured to determine if this method was convenient for distinguishing polyploidy. The results drew a distinction between diploid and polyploidy cultivars, but not between triploid and tetraploid. The genotypes of 32 cultivars were investigated by using five SSR markers to estimate the correspondence with the FCM ploidy levels and to analyze the genetic diversity. The ploidy estimated from the maximum number of alleles per locus corresponded with that estimated by FCM among the diploid and triploid cultivars, but not among the tetraploids. Among the diploid potted cultivars, only three or four alleles were found, and most of the alleles were also found in the diploid cut cultivars. On the other hand, triploid and tetraploid potted cultivars had four to eight alleles, and most were unique to a given ploidy levels. SSR analysis suggested that diploid potted cultivars were derived from cut cultivars because of their close genetic relationship, and that the triploids and tetraploids were produced by crossing wild Dianthus spp. and similar genetic resources because of their unique genetic background. In total, 30 potted cultivars with different ploidy levels could be successfully differentiated using five SSR markers.},
 pages = {53--89},
 title = {カーネーションにおける DNA マーカーの育種への利用と品種多様性に関する研究},
 volume = {9},
 year = {2009},
 yomi = {ヤギ, マサフミ}
}