The Horticulture Journal
Online ISSN : 2189-0110
Print ISSN : 2189-0102
Volume 87 , Issue 1
Showing 1-16 articles out of 16 articles from the selected issue
INVITED REVIEW
  • Akifumi Azuma
    Type: Invited Review
    2018 Volume 87 Issue 1 Pages 1-17
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: June 10, 2017
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    Because of the commercial importance of grapes (Vitis spp.), it is important to understand how grape coloration is affected by genetic and environmental factors, as this knowledge may contribute to more stable production of high-quality grapes. The color of berry skins is determined mainly by the quantity and composition of anthocyanins. This review summarizes the results of recent studies of the genetic and environmental regulation of anthocyanin biosynthesis in grape berry skin: (i) The myeloblastosis (MYB) haplotype composition at the color locus is the major genetic factor that determines the anthocyanin content. (ii) The MYB haplotype composition at the color locus and the anthocyanin O-methyltransferase locus are major genetic determinants of the ratios of tri- to di-hydroxylated anthocyanins and of methylated to non-methylated anthocyanins. (iii) The accumulation of anthocyanins depends on both low temperature and light, and the two factors have a synergistic effect on the expression of genes within the anthocyanin biosynthesis pathway. (iv) Comprehensive transcriptome analysis using a grape oligo-DNA microarray let my research group identify many candidate genes involved in low-temperature-induced abscisic acid signaling and light signaling networks related to anthocyanin accumulation in grape berry skin. These findings will allow prediction of the skin color of grapes from seedlings at a very young stage by examining the MYB haplotype composition. Furthermore, these results will contribute to a fuller understanding of how grape coloration is affected by environmental factors, thereby helping grape growers to develop cultivation techniques that contribute to the production of highly pigmented grapes.

ORIGINAL ARTICLES
  • Toshihiko Sugiura, Mikio Shiraishi, Shohei Konno, Akihiko Sato
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 18-25
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: April 26, 2017
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    To develop a method for predicting the skin color of grape berries of three cultivars of Vitis labrusca L. × Vitis vinifera L. grown in Japan, we investigated the relationship between skin color and air temperature in the grape production areas of 18 prefectures. When mean air temperature during the 40 days before harvest date was ≥24°C, the skin color ratings of ‘Kyoho’, ‘Pione’, and ‘Suzuka’ were significantly negatively correlated with temperature. Skin color ratings decreased by about 1 unit per 1°C increase; at a given mean air temperature during this period, the rating of ‘Suzuka’ was higher (by 0.7 units) than that of ‘Kyoho’, which was higher (by 1.0 unit) than that of ‘Pione’. Because an approach to predict harvest date has not been established, we developed a method to predict skin color at harvest based on air temperature after the full-flowering date. We found the times that had a strong negative correlation between the mean air temperature and the skin color rating at harvest was 43 days from 50 DAF (days after full flowering) for ‘Kyoho’, 46 days from 46 DAF for ‘Pione’, and 42 days from 52 DAF for ‘Suzuka’. We obtained a linear regression equation for the relationship between the skin color rating at harvest and the mean air temperature during the periods. If the full-flowering date is known, it is possible to predict skin color at harvest by using this equation and the predicted air temperature after full flowering. We also developed a method for predicting anthocyanin contents in berry skins at harvest using significant regressions among the skin color rating, the skin anthocyanin content, and mean air temperature.

  • Hisashi Yamada, Shun Ito, Daisuke Toshinari, Keiko Kataoka, Tsuyoshi H ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 26-33
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: June 21, 2017
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    To apply the beneficial results obtained for potted citrus trees to field-grown ones, the effects of seawater application on soil electrical conductivity (EC), water relations, and fruit quality in field-grown satsuma mandarin (Citrus unshiu Marcow.) trees were determined. In 2010, periodical applications of smaller amounts of half-strength-diluted (1/2X) or undiluted seawater (1X) delayed the reduction of leaf water potential to the objective level at 0.3 to 0.5 MPa lower than that in the control, resulting in an insignificant increase in soluble solids content (SSC). Thus, half of the total amount of 1X per area applied in 2010 was irrigated once or twice in September in 2012 and 2013. Soil EC in 1X markedly increased after just the first application at above 1.8 dS·m−1 and was kept at a significantly higher level than in the control until harvest, although it gradually decreased by leaching due to rainfall. Leaf water potential at predawn was reduced by 1X and the objective value was achieved from early-October and mid-September to harvest in 2012 and 2013, respectively. SSC was higher in 1X than the control throughout the experimental period and the difference between 1X and the control at harvest was 1.4 and 1.2°Brix in 2012 and 2013, respectively. Other fruit quality parameters including titratable acidity (TA) were not significantly affected by seawater irrigation in either year, except for fruit size which was slightly inhibited in 1X. No difference was observed in the leaf chlorophyll index and abscission between 1X and the control, although the Na content in the leaves was increased in 1X. These results suggest that application of relatively higher amounts of undiluted seawater in the early stage of maturation could induce moderate salt or water stress through the inhibition of water absorption by roots and improve fruit quality by increasing SSC without any visible leaf injury in field-grown satsuma mandarin trees.

  • Taku Yano, Akiyoshi Morisaki, Kimiaki Matsubara, Shun-ichiro Ito, Masa ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 34-42
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: July 21, 2017
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    To establish cultural practice based on a consecutive growth model for potted 1-year-old seedlings of Satsuma mandarin (Citrus unshiu Marc.), growth analysis by classical and functional approaches was conducted under different light conditions and air temperatures over 2.5 years, and the active growth of potted seedlings in the greenhouse was investigated. Under the classical approach, the general change patterns of relative growth rate (RGR) and net assimilation rate (NAR) were hard to determine because of irregularities including quiescence of vegetative growth. Under the functional approach, plant mass modeled using linear, exponential, power-law, monomolecular, three-parameter logistic, four-parameter logistic (4L), and Gompertz functions showed significant correlations with the observed plant mass. 4L was the best model because it showed the highest r, and the lowest root mean square error and Akaike Information Criterion, so RGR and NAR were estimated by 4L. Analysis of the RGR components showed significant positive correlations between RGR and NAR. Analysis of covariance indicated the NAR costs for increasing RGR were lower in the greenhouse than in open culture; this was explained by differences in specific leaf area (SLA). Therefore, in greenhouse culture, growth was primarily enhanced by NAR as net photosynthesis and underpinned by SLA as a morphological trait improvement for the relatively low light intensity compared with open culture. A multiple regression model for NAR using the pooled data (n = 60) suggested solar radiation had a positive effect (P < 0.0001) and air temperature had a negative effect (P < 0.01) on NAR.

  • Sogo Nishio, Shingo Terakami, Toshimi Matsumoto, Toshiya Yamamoto, Nor ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 43-54
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: July 21, 2017
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    The chestnut (genus Castanea) has a long juvenile phase, and breeders have to wait three years or more to evaluate nut traits. Therefore, molecular markers associated with genes of interest are required to speed the selection process in chestnut breeding programs. Genetic linkage maps of the Japanese chestnut were constructed using two breeding populations derived from crosses between ‘Kunimi’ and breeding line ‘709-034’ (Kx709), and between ‘Porotan’ and ‘Tsukuba-43’ (Px43). Maps of the four parents and two integrated maps (one representing each cross) were constructed using 443 simple sequence repeat markers (SSRs) and 554 single-nucleotide polymorphism markers. In the Kx709 integrated map, which was the most saturated of the six maps, 12 linkage groups were identified that covered 668.1 cM with an average distance of 0.8 cM between loci. Using anchor SSRs, these six maps were successfully aligned to the Chinese chestnut consensus map. We evaluated eight important traits, including several nut traits, to identify molecular markers associated with these traits. At least one significant quantitative trait locus (QTL) was detected for each of the eight traits (21 in total). Logarithm of odds (LOD) values and phenotypic variance explained by these QTLs ranged from 2.60 to 7.90 and from 11.6% to 29.1%, respectively. In the Kx709 population analysis, several QTLs for nut harvesting date (HARVEST) and pericarp splitting (SPLIT) were detected. Under the assumption that the effects of these QTLs are additive, the percentage of total phenotypic variance explained by the combination of QTLs was high for both HARVEST (47.5%–60.8%) and SPLIT (33.4%–41.7%). Because these mapping populations and their parents are essential materials for Japanese chestnut breeding programs, these QTLs will soon be used for marker-assisted selection to improve breeding efficiency.

  • Vahid Tavallali, Soheil Karimi, Omid Espargham
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 55-62
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: July 28, 2017
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    Boron (B) toxicity and salt stress are widely observed in arid and semi-arid regions. Nonetheless, little is known about the interactions between B and salt stress with respect to plant defense systems. In this study, seedlings of Pistacia vera ‘Badami’—a valuable crop of arid lands in central Persia—were treated with different B concentrations in soil (0, 2.5, 5, 10, and 20 mg·kg−1) to investigate oxidative injuries and antioxidative defense responses of the plants to salt stress (0, 800, 1600, and 2400 mg NaCl·kg−1 of soil). Salt stress and application of 20 mg B·kg−1 of soil intensified electrolyte leakage, lipid peroxidation, and lipoxygenase activity in pistachio leaves. Additional supplementation of B up to 5 mg·kg−1 soil significantly decreased malondialdehyde (MDA) and H2O2 under salt stress. The alleviating effects of B on oxidative stress parameters were related to the improvement in antioxidant enzymes activity (ascorbate peroxidase and catalase), and the non-enzymatic antioxidant compounds (ascorbic acid and phenolic compounds), compared with those treated with either salt stress or a high concentration of B. However, application of 20 mg B·kg−1 of soil exacerbated the oxidative damage induced by salt stress. On the contrary, applying mild salt stress mitigated the toxic effects of B on the plant, since oxidative stress due to B toxicity was significantly reduced by application of 800 mg NaCl·kg−1 of soil. In conclusion, the optimization of B supply in the soil was suggested to alleviate the oxidative damage due to salt stress.

  • Nur Aeni Ariyanti, Kotaro Torikai, Rizky Pasthika Kirana, Sho Hirata, ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 63-72
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: March 31, 2017
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    Wide-ranging varieties and/or strains of bulb onions (Allium cepa Common onion group) and shallots (A. cepa Aggregatum group) were utilized to understand the variation in chemical compounds responsible for their taste. The bulb samples of 10 F1 commercial onion varieties (seven short-day and three long-day varieties) from Japan and 12 shallot landraces from abroad (Vietnam: three landraces; Indonesia: nine landraces) were collected as plant materials once a year in 2014 and 2015. The contents of S-alk(en)yl-L-cysteine sulfoxides, total flavonoids, and soluble sugars—including fructose, glucose, sucrose, and fructans—were determined to find differences between bulb onions and shallots, as well as to detect variations among varieties and/or landraces. While a principal component analysis (PCA) based on the results from both 2014 and 2015 could clearly discriminate shallots from bulb onions from a phytochemical perspective, bulb onions mainly had higher monosaccharides than shallots. By contrast, shallots produced more disaccharides than bulb onions. In most cases, regression analyses using the numerical data of the chemical compounds found in bulb onions and shallots suggested year-year correlations between 2014 and 2015. The flavonoid and PeCSO (S-(1-propenyl)-L-cysteine sulfoxide: isoalliin) contents in shallots were higher than those detected in bulb onions, which indicated the stronger pungent and bitter taste could be attributable to excess amounts of these compounds in this tropical plant.

  • Masaaki Takahashi, Chie Yoshida, Toshikazu Komoda
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 73-79
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: June 10, 2017
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    A light irradiation method was found to promote coloring in sweet pepper fruit (Capsicum annuum L.) harvested at the breaker stage of mature green fruit. In summer and autumn culture, heating systems are not usually used, and a large amount of uncolored fruit remains after harvest because of low temperatures and/or insufficient sunlight. We investigated the use of light irradiation to enhance the color of the fruit post-harvest and found that light intensities between 50 μmol·m−2·s−1 and 200 μmol·m−2·s−1 made no difference to the coloring rate; however, higher intensities resulted in an increase in the carotenoid content, which is responsible for the color in red sweet pepper fruit. Although temperatures of 15–25°C with light irradiation are considered to be appropriate for fruit coloring, the transpiration rate was found to increase in propotion to temperature rises, and the fruit wilted at 25°C. We also confirmed that fruit colored more than 50% by light irradiation continued getting colored in the dark at temperatures above 15°C. This combination of light irradiation and dark processing may potentially improve the ripening process efficiency and preserve the market value of fruit.

  • Jun-ichiro Masuda, Yukio Ozaki, Michikazu Hiramatsu, Kaori Sakai, Jung ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 80-88
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: July 04, 2017
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    Effects of photoperiod and temperature on rhizome enlargement (dormancy induction) and accompanied dormancy depth were investigated in this study. Nine-day-old seedlings were transplanted from 26 July at 1 week intervals, and they were grown under a natural photoperiod for 5 weeks in an unheated greenhouse in Fukuoka Prefecture, Japan. Although subterranean stems elongated in the plants grown until 30 August or 6 September, enlarged rhizomes were formed in those grown until 13 September or 20 September. It was revealed from these results that the lotus recognizes a natural photoperiod after 6 September as a short day. When 9 treatments of day length combinations (LD0+SD8–LD8+SD0) were applied to the seedlings, the plants grown under short day after long day treatment of 0 (LD0+SD8), 1 (LD1+SD7), 2 (LD2+SD6), 3 (LD3+SD5), 4 (LD4+SD4), 5 (LD5+SD3), 6 (LD6+SD2), or 7 (LD7+SD1) weeks formed enlarged rhizomes from the fifth, fifth, sixth, seventh, eighth, tenth, twelfth, and fourteenth internodes, respectively. Although photoperiodic treatment in the first week was different between LD0+SD8 and LD1+SD7 treatments, subterranean stems began to enlarge from the same internode (fifth internode) in both treatments. This indicates that photoperiod treatments for the first week do not affect morphology of subterranean stems. Seven treatments of day length combinations (LD2+SD0+LD6–LD2+SD6+LD0) were applied to seedlings after long day treatment for 2 weeks. Enlarged subterranean stems were observed in the plants grown under short day for 6 weeks (LD2+SD6+LD0), but not in those under long day for 6 weeks (LD2+SD0+LD6). On the other hand, subterranean stems elongated again after rhizome enlargement under a subsequent long day following 1 (LD2+SD1+LD5), 2 (LD2+SD2+LD4), 3 (LD2+SD3+LD3), or 4 (LD2+SD4+LD2) weeks of short day. This clarified that morphogenesis in subterranean stems is completely dependent on photoperiod. Further, it is expected that such growth resumption may be attributed to a weak dormant state in the enlarged rhizome. The enlarged rhizomes were exposed to natural low temperatures to examine environmental factors for deepening dormancy. Rhizomes sprouted in all treatments irrespective of exposure to low temperatures when they were transferred to ideal conditions. Rapid growth in leaves and subterranean stems was particularly observed by exposure to low temperature. It was suggested that low temperature is an environmental factor for releasing dormancy, but not for deepening dormancy. It is proposed from these results that subterranean stem growth is completely dependent on photoperiod, and that enlarged rhizomes show weak dormancy.

  • Takanori Masukawa, Kyeong-Seong Cheon, Daiki Mizuta, Akira Nakatsuka, ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 89-96
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: July 05, 2017
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    Flavonoid 3'-hydroxylase (F3'H) has an important role in determining anthocyanin patterns in plants. Here, we analyzed root coloration characteristics in the radish by investigating anthocyanidin and expression of F3'H genes in cultivars with purple, red, or white roots. Cyanidin was detected in the roots of the purple radish, while pelargonidin was found in the red radish; however, neither of these anthocyanidins was detected in white radish. We isolated the RsF3'H gene of the purple root radish and found that it showed a relatively higher level of expression compared to the RsF3'H of the red radish. Moreover, we identified a retrotransposon, gypsy-Ty3, in the first exon of the F3'H homolog in the red radish. These results suggested that the F3'H enzyme may determine cyanidin-based anthocyanin in the purple radish, and that the lack of F3'H function due to the retrotransposon insertion, contributed to pelargonidin-based anthocyanin accumulation in the red radish.

  • Tran Duy Vinh, Yuichi Yoshida, Mitsuo Ooyama, Tanjuro Goto, Ken-ichiro ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 97-105
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: November 17, 2017
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    Blossom-end rot (BER) in tomato has been generally reported as a calcium (Ca)-related physiological disorder influenced by cultivar and environmental factors. In our previous works, we found that different fruit-sized cultivars could share a similar threshold value of water-soluble Ca. In addition, seasonal susceptibility to BER was closely related to fruit growth rate. This study aimed to clarify the effect of fruit growth rate as a dominant factor determining the susceptibility in different fruit-sized tomato cultivars. A large-sized cultivar, ‘Momotaro Fight’, and medium-sized ‘Cindy Sweet’, with different susceptibility to BER disorder, were hydroponically grown with modified Hoagland nutrient solutions consisting of a range of Ca:K (potassium) ratios in four cropping seasons. In spring and summer, BER incidence was more than 60 and 10% in ‘Momotaro Fight’ and ‘Cindy Sweet’, respectively, when plants were fed with low Ca. BER was rarely observed when water-soluble Ca exceeded 0.30 μmol·g−1 FW, and the rate of BER incidence increased with a decrease in water-soluble Ca concentration in both cultivars. Fruit growth rate was much more vigorous in ‘Momotaro Fight’ than ‘Cindy Sweet’, especially in summer. It was significantly favored by the increased temperature and solar radiation in both cultivars. The multiple regression analyses detected a significant effect of fruit growth rate on BER incidence, exclusively in ‘Momotaro Fight’. Together with water-soluble Ca, fruit growth rate explained over 50% of the variation of BER incidence. A vigorous rate of fruit growth can play a more important role in decreasing water-soluble Ca in ‘Momotaro Fight’, and result in severe and frequent BER incidence, compared to ‘Cindy Sweet’. Thus the cultivar difference in the susceptibility to BER is likely explained by the difference in the growth rate of young fruit affecting water-soluble Ca in the distal part of tomato fruit.

  • Takashi Onozaki, Masahiko Yamada, Masafumi Yagi, Koji Tanase, Michio S ...
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 106-114
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: April 05, 2017
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    Flower vase life of cut ornamental flowers, including carnations, is important in determining their quality and consumer preference for cut flowers. Therefore, we repeatedly crossed and selected promising offspring with long vase life for seven generations, from 1992 to 2008, in order to improve the vase life of carnation (Dianthus caryophyllus L.) flowers using conventional cross-breeding techniques. We investigated flower vase life, ethylene production at natural senescence, ethylene production after ethylene treatment (autocatalytic ethylene biosynthesis), response time to ethylene treatment (ethylene sensitivity), and flower diameter in six carnation cultivars used for initial breeding materials and a total of 123 selected lines from the first to seventh generations. Our results indicate that there was a large genetic variability in the five traits. Significant negative correlations were observed between flower vase life and ethylene production at natural senescence (r = −0.88**), between flower vase life and ethylene production after ethylene treatment (r = −0.90**), and between flower vase life and flower diameter (r = −0.92**). However, there was no correlation between flower vase life and ethylene sensitivity. Thus, the long vase life of selected carnation lines was strongly associated with a decrease in their ethylene production. Our results indicate that variation in flower vase life is not due to differences in ethylene sensitivity, but due to differences in ethylene production. Although flower size is an important floricultural trait for commercial production, crossing and selection for flower vase life resulted in a considerable reduction in flower diameter. The course of mean flower vase life over generations showed that selection was effectively made in the first to sixth generations. Repeatability for the flower vase life was roughly constant (0.3 to 0.4) in the first to sixth generations, but decreased to 0.12 in the seventh generation, suggesting a decrease in genetic variation in the seventh generation.

  • Sho Yamamoto, Yutaka Yamagiwa, Zentaro Inaba, Takashi Handa
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 115-123
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: May 09, 2017
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    Lilium japonicum Thunb. which has pink or white-colored funnel-like flowers, is distributed in Kyushu, Shikoku, and the western part of Honshu, the main island of Japan. L. auratum Lindl. which has large white flowers with yellow central stripes and red spots, is distributed in the eastern part of Honshu. Natural hybridization of these two species has only been found on the Izu Peninsula of Honshu. However, details of the variation and hybridity of the interspecific hybrid population of these species on this peninsula remain unknown. In the present study, we conducted a morphological examination using 43, 21, and 90 individuals of L. japonicum, L. auratum, and the putative hybrid, respectively, from six, four, and ten populations of the Izu Peninsula, respectively. In addition, we performed simple sequence repeat (SSR) analysis using 47, 41, and 106 individuals of L. japonicum, L. auratum, and the putative hybrid, respectively, from six, four, and ten populations, respectively. Putative hybrid populations that resembled L. japonicum in morphology and SSR profile were found in the southern to eastern part of the peninsula, whereas those that resembled L. auratum and those exhibiting an intermediate morphology and SSR profile were found in the southern part of the peninsula. Large morphological variations exist in putative hybrid in the southern population, and interspecific hybridization has occurred in the southern and eastern populations. These results suggest that the center of natural hybridization is located in the southern part of the Izu Peninsula.

  • Tawanda Elias Maguvu, Yohei Higuchi, Michio Shibata
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 124-131
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: May 25, 2017
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    Portulaca umbraticola is an ephemeral flower that opens early in the morning and wilts in the late afternoon. Although light and temperature act as major external cues to limit the velocity of flower opening, endogenous factors regulating its timing are largely unknown. In this study, we used time lapse photography to study the effect of different photoperiods and light qualities on the flower opening rhythm of Portulaca umbraticola. When illumination was provided, flower opening was rapid and most of the flowers reached the full opening stage. In contrast, in continuous darkness (DD), progression of flower opening was similar to other treatments only during the earlier stages of flower opening; thereafter, progression was significantly slower and most flowers did not progress up to the full opening stage. A robust flower opening rhythm with a period of approximately 24 h was observed in DD for at least three days and flower opening was strongly synchronous. In contrast, continuous white (LL) and continuous red (RR) lights showed a less robust rhythm with periods of approximately 21 and 22 h, respectively, for the first two days and from the second to the third day arrhythmia developed. Continuous blue light (BB) mirrored DD, with a period of approximately 25 h. Under the different photoperiods used (20L/4D, 18L/6D, 16L/8D, 12L/12D, 8L/16D, and 4L/20D), flower opening occurred earlier at longer photoperiods in comparison with shorter photoperiods, relative to the reference point (17:00). However, when the dark period was less than 6 h, loss of synchronicity of flower opening was observed. Synchronicity of flower opening was only set when the dark period was greater than or equal to 6 h.

  • Mi Sang Lim, Sun Hee Choi
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 132-139
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: July 12, 2017
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    The genetic diversity and relationships among plants belonging to the subfamily Sedoideae (Crassulaceae), some of which are indigenous to Korea or introduced from other countries, were determined using chloroplast (cp) nucleotide sequence analysis. To analyze genetic diversity and variation among 19 plants including species belonging to Sedum, Hylotelephium, and Phedimus, the tRNA-Leucine gene (trnL [UAA]) and adjoining spacer in chloroplast DNA (cpDNA) were sequenced and compared across species. Species were divided into two main groups based on the cpDNA sequence comparison. The generated phylogeny indicated that many native Sedum species had diverged from S. album. Members of the Phedimus and Hylotelephium species, and several Sedum species analyzed here, clustered distinctively in different groups. Using cpDNA sequence analysis, we successfully discriminated Sedoideae plants cultivated in Korea from each other, even at the intraspecific level, and the results were reflective of the morphological and biogeographical characteristics. These findings could be useful for classifying samples for proper naming, choosing breeding materials for new cultivars, or identifying species for conservation of horticultural crop resources.

  • Sho Ohno, Wakako Hori, Munetaka Hosokawa, Fumi Tatsuzawa, Motoaki Doi
    Type: Original Articles
    2018 Volume 87 Issue 1 Pages 140-148
    Published: 2018
    Released: February 06, 2018
    [Advance publication] Released: August 04, 2017
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    Bicolor flowering dahlias are a group of cultivars that produce inflorescences with bicolored petals characterized by a colored basal part and a white tip. However, they frequently produce single-colored petals, even if they are vegetatively propagated. In a previous study, strong relationships between inflorescence color and leaf phenotype were observed in a red–white bicolor flowering dahlia ‘Yuino’; red petal-producing individuals accumulate flavonoids in leaves, whereas only bicolor petal-producing individuals tend not to accumulate them in leaves. Flavonoids in leaves are assumed to be chalcones. In this study, we investigated flavonoids in the leaves of ‘Yuino’ by nuclear magnetic resonance analysis and identified six caffeoyl esters, four flavonol derivatives, and three novel butein derivatives in the flavonoid-rich leaves of ‘Yuino’. The three novel compounds were butein 4',4-O-di-[2-O-(β-glucopyranosyl)-β-glucopyranoside], butein 4'-O-[2-O-(β-glucopyranosyl)-β-glucopyranoside]-4-O-β-glucopyranoside, and butein 4'-[6-O-(3-hydroxy-3-methylglutaryl)-β-glucopyranoside]-4-O-β-glucopyranoside. On the other hand, only caffeoyl esters were detected in flavonoid-poor leaves. These data demonstrated that flavonoid-rich leaves accumulated the flavonoids of butein and flavonol derivatives. The common enzyme for the biosynthesis of butein and flavonol derivatives is chalcone synthase; thus, the importance of chalcone synthase for phenotypic lability in ‘Yuino’ was confirmed.

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