• Journal of Practical Agriculture & Fisheries Research
• /
• v.22 no.1
• /
• pp.131-142
• /
• 2020

Chrysnathemum stunt viroid (CSVd), a small, single-stranded, infectious RNA, has caused a severe problem in chrysanthemum in the world. In Korea, since CSVd was firstly observed in 1997, the disease has been spread throughout the whole country rapidly. In spite of the seriousness, few methods for control of CSVd have been known without prevention. The use of resistant cultivars is one of the most efficient approaches for overcoming CSVd disease in chrysanthemum cultivation. This study was carried out to identify chrysanthemum genetic resources for the resistance to chrysanthemum stunt viroid (CSVd). A total of 192 commercial cultivars including 167 spray and 25 standard chrysanthemum were screened with CSVd through grafting inoculation method. In most of the inoculated cultivars, typical disease symptoms, stunting of plant height, reduced flower size, and flower color bleaching, were induced. Several cultivars, however, were symptomless or showed delay in symptom expression. Of 192 chrysanthemum cultivars, two cultivars with less than 5% of the average reduction rate of plant height, 'Chiwerel' and 'Jeongheungdaesin', were rated as resistant. And six cultivars less than 20% inculding 'Inga' were rated as moderate resistant. The remaining 184 cultivars with a high level of reduction were rated as susceptible. We expect that these genetic resources can be used in crossbreeding programs for developing CSVd resistant cultivars of chrysanthemum.

• Horticultural Science & Technology
• /
• v.28 no.3
• /
• pp.449-455
• /
• 2010

'Moulinrouge' was selected as the best regenerating cultivar among 18 different spray-type chrysanthemum cultivars bred in the Gyeongnam Flowers Breeding Research Institute. When the leaf explants from standard- and spray-type chrysanthemum 'Jinba' and 'Moulinrouge' were incubated on MS basal medium supplemented with $0.5mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA, both 'Jinba' and 'Moulinrouge' induced adventitious shoots that can be regenerated into plantlets. Based on these regeneration conditions, we developed an efficient $Agrobacterium$-mediated chrysanthemum 'Moulinrouge' transformation method by using sequential selection of shoots from low ($10mg{\cdot}L^{-1}$) to high ($30mg{\cdot}L^{-1}$) concentrations of kanamycin after co-cultivation of leaf explants with $Agrobacterium$ for 10 days and induction of shoots. All kanamycin resistant plants investigated with genomic PCR analysis carried the report gene, $AtSICKLE$, in their genome. Although expression levels of the report gene in the transgenic plants investigated with RT-PCR were relatively low because of inefficiency of CaMV 35S promoter in chrysanthemum, transgenic lines expressing $AtSICKLE$ efficiently showed leaf epinasty phenotype. We expect that our results will provide a useful method that can perform a high-throughput investigation of genes isolated and studied well in model plants for molecular breeding of chrysanthemum.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.4
• /
• pp.231-237
• /
• 2010

This study was conducted to improve commercial quality of a cut spray chrysanthemum 'Ilweol' bred in Korea by foliar application of daminozide, suppressing excessive elongation of peduncle caused by high temperature in summer season production. Applications were made at three floral bud developmental stage (I, II, and III), and concentrations used were 0, 500, 1000, and $2000mg{\cdot}L^{-1}$. Cut flower length and peduncle length showed the greatest repression of elongation through daminozide treatments at stage III and stage II, respectively. Daminozide also gradually reduced values of those in a concentration-dependant manner. Flower diameter increased compared to control as daminozide was sprayed at later stage but decreased in daminozide concentration-dependant manner. Angle of flower cluster on apical part of whole plant showed the best results when sprayed with $2,000mg{\cdot}L^{-1}$ at stage III. Among all combinations, $2,000mg{\cdot}L^{-1}$ daminozide at stage II recorded the highest angle of flower cluster and showed 31.3% increment as compared to control. The number of fully expanded flowers showed the highest values using $2,000mg{\cdot}L^{-1}$ daminozide at stage III than the other treatments and total floral buds also showed the highest values using $2,000mg{\cdot}L^{-1}$ daminozide at stage I than the other treatments. In cut spray chrysanthemum cultivar 'Ilweol' bred in Korea, foliar-applying with $2,000mg{\cdot}L^{-1}$ at stage III most effectively suppressed excessive peduncle elongation, angle of flower cluster, and increased the number of flowers in summer. However, this combination affected negatively the other commercial qualities, reducing cut flower length and flower diameter. Therefore, we recommended that foliar application stage and daminozide concentration was stage III and $500mg{\cdot}L^{-1}$, respectively, in a practical culture and cut flower quality for 'Ilweol'.

• Horticultural Science & Technology
• /
• v.28 no.5
• /
• pp.818-827
• /
• 2010

A full-length cDNA and genomic DNA of a $leucoanthocyanidin$ $dioxygenase$ ($DgLDOX$) gene was isolated from the petals of chrysanthemum 'Argus', and comparative features of the gene among three flower color mutants derived from a gamma-ray mutagenesis were characterized. The cDNA coding region of the gene was 1068 bp and was translated into 356 amino acids accordingly. The genomic DNA size was 1346 bp for 'Argus', while three mutants revealed ranges of 1363 to 1374 bp. A single intron between two coding exons for the $DgLDOX$ gene was found, of which size was 112 bp for 'Argus', but 128 or 137 bp for three flower color mutants, indicating that a genomic insertion in the intron occurred during the gamma-ray mutagenesis. DNA blot analysis revealed the $DgLDOX$ gene presenting as a single copy in the chrysanthemum genome. The $DgLDOX$ gene was expressed in both 'Argus' of light-pink color and two purple color mutants (AM1 and AM3) but had very weak expression in only white color mutant (AM2). The results demonstrated that variations in the flower color of the mutants might be associated with changes in the amino acid moieties in the coding exons or fragment insertions in the intron of the $DgLDOX$ gene, which potentially resulted in less expression of the gene in the white colored mutant.

• Horticultural Science & Technology
• /
• v.30 no.2
• /
• pp.162-170
• /
• 2012

The objectives of this study were to isolate and the sequence of novel $F3'H$ gene related to an anthocyanin pathway, and to confirm the expression patterns of the gene involved in the flower color variations of chrysanthemum mutants. In this study, we isolated the full-length cDNAs and the genomic DNAs of an $F3'H$ gene from a wild type (WT) chrysanthemum (cv. Argus) and its three color mutants. The sequence analysis revealed a putative open reading frame of 1,527 bp that encodes a polypeptide of 509 amino acids. Sequence homology ranged from 97% to 99% between 'Argus' and its three color mutants. The sequence analysis from the genomic DNA revealed that the chrysanthemum $DgF3'H$ gene consisted of three exons and two introns spanning a 3,830 bp length. The sizes of the gene for three mutants ranged from a shorter size of 3,828 bp to a longer size of 3,838 bp when compared to the size of WT. The total size of the two introns was 2,157 bp for WT, but those for three color mutants ranged from 2,154 bp to 2,159 bp. A result of an RT-PCR analysis indicated that the color variations of the mutants AM1 and AM2 can be partly explained by the structural modification derived from the sequencial changes in the gene caused by gamma ray. A Southern blot analysis revealed that the $DgF3'H$ gene existing as multiple copies in the chrysanthemum genome. A systemic study will be further needed to provide a genetic mechanism responsible for the color mutation and to uncover any involvement of genetic elements for the expression of the $DgF3'H$ gene for the color variation in chrysanthemum.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.2
• /
• pp.121-127
• /
• 2009

This study was conducted to improve commercial quality of a cut spray chrysanthemum 'Gama' bred in Korea by foliar application of daminozide (DMZ), suppressing excessive elongation of peduncle caused by high temperature in summer season production. Applications were made at three floral bud developmental stages (I, II, and III), and concentrations used were 0, 500, 1000, and $2000mg{\cdot}L^{-1}$. Both cut flower length and peduncle length showed the greatest suppression of elongation by DMZ treatments at stage II. DMZ also gradually reduced values of those in a concentration-dependant manner. Stem thickness and flower diameter reduced compared to control as DMZ was sprayed at later stage and those two characteristics decreased in a concentration-dependant manner. The number of paralleled flowers neighboring apical part of whole plant showed the best results at stage I and II. As for DMZ concentration, those increased effectively at $500-1,000mg{\cdot}L^{-1}$. Among all combinations, $1,000mg{\cdot}L^{-1}$ DMZ at stage II recorded the most paralleled flowers and showed 24.2% increment as compared to control. The number of fully expanded flowers and total floral buds also showed the highest values using $1,000mg{\cdot}L^{-1}$ DMZ at stage II than the other treatments. In cut spray chrysanthemum cultivar 'Gama' bred in Korea, foliar-spraying with $1,000mg{\cdot}L^{-1}$ DMZ at stage II most effectively suppressed excessive peduncle elongation, parallelled flower cluster arrangement, and increased the number of flowers in summer. However, this combination affected negatively the other commercial qualities, reducing cut flower length, stem thickness, and flower diameter. Therefore, we recommended that foliar-spraying stage and DMZ concentration was stage I and $1,000mg{\cdot}L^{-1}$, respectively, in a practical culture for 'Gama'.

• Horticultural Science & Technology
• /
• v.32 no.5
• /
• pp.721-729
• /
• 2014

This study was conducted to improve the consumption of floriculture plants by researching preferences of consumers for the main types of cut flowers. We analyzed the results of surveys, carried out by a company, that were largely about roses, chrysanthemums, and lilies. After departmentalizing consumers into groups and analyzing the results through conjoint and cluster analysis, we found that consumers showed a higher rate of use based on price and vase life than on flower color and flower shape in roses. The groups of rose consumers preferred a price of 1000 won, spray type flower shape, vase life of 7-8 days, and red flower color. In chrysanthemums, consumers showed higher rate of use for flower color than for vase life, flower shape, and price. The groups of chrysanthemum consumers preferred a price of 1000 won, standard flower shape, 16-20 days vase life, and yellow flower color. In lilies, consumers showed higher use rate for flower shape than vase life, price, and flower color. Lily consumers preferred a price of 2000 won, large flower shape, 4-7 days vase life, and yellow flower color. Thus, the major cut flowers (rose, chrysanthemum, and lily) all showed highest use rates in for vase life. These results highlight the importance of understanding the characteristics of consumer interests. They also emphasize that we should plan and create market-oriented and consumer-oriented products to improve the consumption of floriculture plants.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.2
• /
• pp.137-140
• /
• 2009

A new spary chrysanthemum(Dendranthema grandiflorum) cultivar 'Noble Wine' was developed from a cross between 'SL03-01' and 'Artist Pink' by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extention Services(ARES) from 2003 to 2007. Its characteristics were investigated three times from 2005 to 2007 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Noble Wine' was October 26th, and yearround production was possible by day length treatment. Its capitulum was 5.4 cm in diameter, and had 21.6 ray florets and 28.5 head per stem in autumn. Its ray floret was red-purple with green central zone. 'Noble Wine' was about 45 days in spring, and 'Noble Wine' showed the vase life of 21.3 days in autumn. This cultivar was registered for a commercialization in 2007.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.3
• /
• pp.211-215
• /
• 2010

A new spray chrysanthemum(Dendranthema grandiflorum) cultivar 'Magic' was developed from a cross combination between 'Artist Pink' and 'SP0347' by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services(ARES) from 2003 to 2007. Its characteristics were investigated three times from 2005 to 2007 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Magic' was October 26th, and year-round production was possible by day length treatment. Its capitulum was 6.1 cm in diameter, and had 31.9 ray florets and 11.7 head per stem in autumn. Its ray floret was white-purple with yellow green central zone. Days to flower of 'Magic' was about 43 days in spring, and 'Magic' showed the vase life of 20.6 days in autumn. This cultivar was registered for a commercialization in 2007.

• FLOWER RESEARCH JOURNAL
• /
• v.16 no.4
• /
• pp.229-233
• /
• 2008

A new spary chrysanthemum(Dendranthema grandiflorum) cultivar 'Moulin Rouge' was developed from a cross between 'Delmont' and 'Anjela' by selections of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services(ARES) from 2002 to 2006. Its characteristics were investigated three times from 2004 to 2006 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Moulin Rouge' was October 24th, and year-round production was possible by day length treatment. Its capitulum was 5.3 cm in diameter, and had 22.9 ray florets and 12.2 head per stem in autumn. Its ray floret was bi-color(yellow/orange) with green central zone. 'Moulin Rouge' was about 55 days to flower in spring, and showed the vase life of 21.7 days in autumn. This cultivar was registered for a commercialization in 2007.