Skin color, one of the most important characteristics of grapes, is determined by the accumulation of anthocyanins. It has been shown that the anthocyanin accumulation is influenced by abscisic acid and environmental factors such as temperature and light. However, the mechanism regulating anthocyanin biosynthesis has not yet been clarified. This review presents a brief account of our research on the regulation of anthocyanin biosynthesis in grapes and the mechanism of skin color mutation.

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The fruit characteristics of Shima sarunashi (Actinidia rufa (Siebold & Zucc.) Planch. ex Miq.), indigenous to the warm regions in Japan were determined. Two typical collections were investigated to evaluate fruit characters throughout growth. Starch accumulated gradually from 120 days after full bloom (DAFB), and peaked at 160 DAFB. Along with the reduction of the starch content, the sugar content increased at 180 DAFB. Major sugar components of A. rufa fruit were glucose, fructose, and sucrose. In the early stage of fruit development, quinic acid was predominant, and then the content decreased gradually until 160 DAFB, while the content of citric acid gradually increased after 60 DAFB and that of malic acid increased slightly. A trace amount of soluble oxalate was detected throughout the fruit development period. Ascorbic acid content increased in the early to mid-stages of fruit development. Considering the change in quality, the maturation period of A. rufa fruit was estimated to be 180 DAFB. From the evaluation of mature fruit among 11 local collections, fruit shape varied, being round, ovoid, cylindroidal, and truncate. Fruit weight ranged from 7.4 to 18.6 g. Fruit skin was glabrous and the surface color varied from reddish-brown to brown. Flesh color was basically green or dark green. Exceptionally, in one collection, the flesh was reddish around the core. Soluble solid content of ripened fruit juice ranged from 6.2 to 17.4%. Sugar content varied from 2.0 to 15.6 g/100 g FW. Myo-inositol content ranged from 6.0 to 132.1 mg/100 g FW. Major organic acids were quinic, citric, and malic acid, and quinic acid was predominant. Total acid content ranged from 1.5 to 3.0 g/100 g FW. Total ascorbic acid content ranged from 6.8 to 45.8 mg/100 g FW. In all collections, protease activity in the juice was very low.

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Apples (Malus × domestica Borkh.) have gametophytic self-incompatibility (SI). Generally, the polyploidy breaks down gametophytic SI; however, there is little data on apples. In this study, we collected basic data on the self-compatibility (SC) mechanism of apple autotetraploid cultivars and polyploid mutants of original diploid cultivars. The autotetraploids showed self-fertility, and their pollen was compatible with the pistils of their original diploid cultivars, which share two S-alleles. However, the original diploid cultivars’ pollen was incompatible with the pistils of autotetraploid cultivars. Although the pollen of autotetraploid cultivars induced SC, the fruit set percentage and seed number were lower when autotetraploid cultivars were selfed or used as pollen parents in the pistils of the original diploid cultivars than in compatible diploid cross-combinations. The pollen tubes of autotetraploid cultivars grew significantly further than those of the selfed diploid cultivars, but grew significantly slower than in compatible diploid cross-combinations. These results show that the pollen of apple autotetraploid cultivars induced SC but maintained partial incompatibility.

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We transformed the European pear (Pyrus communis L.) ‘La France’ and ‘Ballade’ with the Citrus FLOWERING LOCUS T (CiFT) gene, which induces early flowering. Subsequent DNA blot analysis of the transformed and wild-type plants indicated that the transformed plants carried 1–4 copies of CiFT. Of the 8 transformed ‘La France’ and 7 transgenic ‘Ballade’ plant lines obtained, 7 and 5 lines respectively, flowered early when cultivated in vitro in a micropropagation medium. No correlation was found between the CiFT copy number and early flowering in vitro, however, the results of RNA gel blot analysis indicated a strong correlation between the expression of the CiFT gene and floral bud differentiation in vitro. Flowers that developed in vitro differed from wild-type flowers in terms of phenotypic traits, such as the number of pistils, petals, sepals, and stamens. To investigate the inheritance pattern of the CiFT gene, we obtained 15 seeds from the fruits of P. communis L. ‘Bartlett’ plants that were cross-pollinated with transgenic line No. 6, which had the second highest expression of the transgene. Of 7 seedlings that expressed the CiFT gene, 5 flowered within 10 months after they were transferred to a greenhouse. This result indicated that the CiFT gene induced early flowering in the transformed pear plants and that their progeny inherited the early flowering phenotype.

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A genetic linkage map of the Japanese pear (Pyrus pyrifolia Nakai) ‘Housui’ was constructed based on simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers. A mapping population derived from a cross between ‘Bartlett’ and ‘Housui’ was used to create the linkage map of ‘Housui’. Segregation data on 63 progeny were scored using a pseudo-testcross strategy. The linkage map of ‘Housui’ consisted of 17 linkage groups (LGs) spanned 1,174 cM with an average distance of 3.5 cM between markers. A total of 335 loci (105 SSRs, 224 AFLPs, and 6 others) were used to construct the genetic linkage map. We successfully aligned all LGs to European pear and apple reference maps with common SSR markers. Compared to the reference map of ‘Bartlett’, constructed using same mapping population, LG 4 and LG 5 of ‘Housui’ were small and covered 9.7 cM and 23.2 cM, respectively. Furthermore, LG 12 of ‘Housui’ was established with only one SSR marker. These results indicated that three particular genomic regions (LG 4, LG 5, and LG 12) of ‘Housui’ were homozygous because a pseudo-testcross strategy was applied to construct the linkage maps. Genotyping of parental and ancestral cultivars of ‘Housui’ demonstrated that homozygous regions were increased on particular LGs of Japanese pear, maybe due to biased crossing and selection of seedlings during the Japanese pear breeding program.

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‘Taibyo VF’, a Japanese rootstock cultivar, is a Solanum grandifolium × S. melongena hybrid that has difficulty setting seed, but F₁ plants of ‘Taibyo VF’ × ‘LS1934’ (S. melongena) produce some seeds. F₂ plants were segregated into male-sterile and fertile plants. All plants in the backcross of sterile progeny with S. melongena were sterile, indicating cytoplasmic male sterility (CMS) caused by the S. grandifolium cytoplasm. This CMS is stable under a range of environmental conditions. In contrast, fertile progeny appear to possess a fertility restoration nuclear gene. We studied the inheritance of this gene. F₁, F₂, and backcross generations from crosses between male-sterile ‘CMS-1’ and fertile ‘FR-1-1’ were obtained. ‘CMS-1’ is the F₁ of male-sterile ‘ER98B-10-2-3-1’ × ‘AE-P08’ (S. melongena). ‘ER98B-10-2-3-1’ is the F₅ and ‘FR-1-1’ is the F₇ of ‘Taibyo VF’ × ‘LS1934’. All ‘CMS-1’ plants were male-sterile; the fertile to male-sterile segregation ratios were 3 : 1 in ‘FR-1-1’, 1 : 1 in F₁ and 3 : 1 in F₂ of ‘CMS-1’ × ‘FR-1-1’, and 1 : 1 in ‘CMS-1’//‘CMS-1’/‘FR-1-1’. Segregation ratios suggested that fertility restoration is controlled by a single dominant gene (Rf) carried heterozygously in ‘FR-1-1’. Restorer lines that carry nuclear Rf homozygously in the cytoplasm of S. melongena have been developed.

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Eight members of the Allium fistulosum L. – shallot (Allium cepa L. Aggregatum group) monosomic addition line (2n = 17, FF + 1A–FF + 8A) proved to be very effective in revealing the effects of single alien chromosomes from A. cepa on the production of polyphenol in the green leaf tissues of A. fistulosum. The determination of polyphenol content in the green leaf tissue of these monosomic additions was carried out monthly from January 2002 to December 2003. Throughout the 2-year period, every monosomic addition accumulated polyphenols in green leaf tissues. Two-way ANOVA revealed significant differences, at the 1% level, in the polyphenol contents of the various monosomic addition types as well as in various months. Dunnett’s test showed that four monosomic additions (FF + 2A, FF + 5A, FF + 6A, and FF + 8A) caused a greater increase in the amount of polyphenol content than did A. fistulosum. The levels of polyphenol accumulation in the remaining four monosomic additions and A. fistulosum were almost the same. A phenylalanine ammonialyase gene of shallot was allocated to chromosome 2A using two sets of the monosomic additions. These results indicate that the genes related to polyphenol production may be located on the 2A, 5A, 6A, and 8A chromosomes of shallot.

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Vigorous seedling growth is a desirable trait for machine-assisted transplanting using a plug nursery system in bunching onion. This study was undertaken to identify the quantitative trait loci (QTLs) controlling seedling growth and to elucidate the modes of gene action of the QTLs. Plant material was a set of reciprocally backcrossed populations (BC₁). These were produced from 2 inbred lines derived from the Senju group and Kujo group. Two corresponding BC₁ maps were constructed by adding co-dominant simple sequence repeat (SSR) markers to the previously reported amplified fragment length polymorphism (AFLP) based maps. Fresh weights of seedlings were measured in 3 seasons using BC₁S₁ families. Remarkable heterosis was observed in F₁ and many BC₁S₁ families. Many QTLs for seedling weight were detected on the 2 maps by composite interval mapping. The phenotypic variation explained by a single QTL was less than 25%. Of these, 3 QTLs on 3 linkage groups are considered to be consistently effective across different environmental conditions because they were detected in different years and seasons. Most QTLs were detected on one map, but were not detected in a corresponding region on the other map; however, the degree of dominance at each locus was calculated to determine whether the locus shows overdominance. Overdominance was observed at some loci, and the other loci showed an additive and dominant effect. It is suggested that remarkable heterosis for seedling weight in the present population is based on the accumulation of dominant and overdominant gene actions.

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The effects of gellan gum gels and Murashige and Skoog (MS) inorganic salts at various strengths on the vase life of ‘Rote Rose’ rose cut flowers were investigated. To form the gels, gellan gum was dissolved with MS salts at various concentrations. To simulate the transport of cut rose flowers, stems were placed in gellan gum gels and held at 23°C for 24 h or 48 h. Cut flowers were then transferred into distilled water and their fresh weight (FW) and vase life were determined. According to the observed vase life and changes in FW, gels formed with 0.2% gellan gum and standard-strength MS salts appear to be the most suitable for cut roses. Although the hardness of gellan gum gel increases with increased concentrations of gellan gum and MS salts, no correlation between vase life and gel hardness was observed. To determine the potential water availability of gellan gum gel, gels were placed in a centrifuge filter device, centrifuged at 3000 × g for 10 min and the amount of water released from the gel was measured. A highly positive correlation between the amount of water released from the gel and water uptake of flowers placed in gellan gum gels was observed. A positive correlation between the amount of water released and vase life was also observed. Thus, using centrifugation to measure the volume of water released from gellan gum gels appears to be a simple and rapid method for evaluating the performance of gellan gum gels as wetting agents.

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‘Jimba’ is the most popular white-flowered chrysanthemum cultivar in Japan. A yellow-flowered cultivar with the same growth properties as ‘Jimba’ will benefit growers because both forms could be produced under the same conditions. Many breeders have therefore tried to produce a “Yellow Jimba” by mutation breeding but have not yet succeeded. Previously, we showed that color mutation from white to yellow in the petals of ray florets is caused by the loss of a carotenoid cleavage dioxygenase gene, CmCCD4a. Here we introduced two separate CmCCD4a RNAi constructs into ‘Jimba’ by Agrobacterium-mediated transformation. The double-transformation effectively suppressed CmCCD4a expression in petals, which became yellow. The yellowest transformants contained 102 μg·g⁻¹ FW carotenoids in the petals, and the expression level of CmCCD4a was 0.4% of the wild-type level. Although the transformed plants were significantly smaller than the wild type, flower size was unchanged. We consider that CmCCD4a could become a powerful tool for petal color manipulation from white to yellow.

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A group of 82 households in a new-built apartment complex in Seoul, Korea participated in an investigation to examine the symptoms of sick building syndrome (SBS) using of houseplants for two observation periods. The present study confirmed the decrease of formaldehyde content in an airtight chamber containing a pot with fatsia plants. Houseplants affected the general air conditions, such as increasing relative humidity and decreasing carbon monoxide and carbon dioxide. The toxic chemical substances responsible for SBS persisted at least one more years but were effectively decreased by ventilation. Houseplants facilitated the quantitative decrease of some of these chemical substances in indoor air. Indoor-dwellers felt the decrease in SBS symptoms with time regardless of houseplants in both observation periods. Houseplants made a slight difference to the symptom degree of SBS in the first observation period but a significant difference in the second observation period; however, houseplants made little difference to the content of toxic chemical substances in indoor air except formaldehyde, although houseplants gave desirable results in the decrease of SBS symptoms.

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The number of buds per inflorescence fluctuates irregularly in the sweet pea (Lathyrus odoratus L.) winter-flowering variety ‘Early Pink’. The number of buds per inflorescence and the fluctuation of the number of buds per inflorescence differ remarkably among plants. The number of buds per inflorescence, diameter of flower stalks, dry matter of cut flowers, and diameter of internodes increased, and short cyclic fluctuations in the number of buds per inflorescence were suppressed as the frequency of removing immature inflorescences increased. Using a moving average, the fluctuation of the number of buds per inflorescence was found to be a combination of two periodic fluctuations in 26 of 36 plants. The 2–3, 4–6, 8–12, and more than 15 node periodic fluctuations were found in 10, 15, 11, and 16 plants, respectively. From these results, the factors that cause the number of buds per inflorescence to fluctuate are discussed.

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The development of leaves and flowers in the wild type and pleiotropic maple-willow (m^w) mutant of Japanese morning glory (Ipomoea nil) was studied to reveal the developmental and regional homology and effects of the m^w gene on the lateral organs. The considerably narrow leaves, sepals, and petals of the m^w mutant result from the inactive marginal meristem, and the small thecae of anthers and the defective septa of ovaries in the m^w mutant are also due to insufficient marginal growth. This suggests that the defective regions of all lateral organs in the m^w mutant are developmentally homologous under regulation by the m^w gene. In the wild type, the fusion of the marginal growth of neighboring primordia is followed by upward growth in the interprimordial regions of floral organs, but in the m^w mutant the defects of this upward growth in the interprimordial regions in the corolla and gynoecium result in apopetalous and apocarpous forms, respectively, except for their normally fused lower portions. It seems that both sympetalous corolla and syncarpous gynoecium of I. nil are formed by two different developmental processes, namely, interprimordial growth and intercalary or zonal growth.

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We estimated the contribution of individual shoot layers in a multi-layered bent canopy to the cut flower productivity of roses (‘Asami·Red’). A two-layered bent shoot canopy was established and upper- or lower-layer bent shoots were replaced with artificial replicas of shoots. Replacing upper-layer shoots with replicas facilitated leaf abscission of lower-layer shoots, resulting in severe reduction in the total dry weight of cut flowers (TDWF) compared with plants having two intact bent shoots. When lower-layer shoots were replaced with replicas, the leaf area of upper-layer shoots increased and consequently the excision of lower-layer shoots had little influence on the TDWF. In another experiment, when a three-layered bent shoot canopy was established and light interception by lower-layer shoots was restricted completely by placing a shading film between two of the three layers, the leaf area of the uppermost shoots increased to compensate for the decreased leaf area due to leaf abscission of lower-layer shoots. The excision of lower-layer shoots resulted in more severe reduction of the TDWF than shading. These results suggest that in a multi-layered bent shoot canopy of roses, upper-layer shoots contribute to cut flower yield of plants, primarily through their current photosynthesis with high light interception. However, lower-layer shoots also contribute to cut flower yield by exporting assimilates retained previously, and hence these shoots should remain on plants until they die spontaneously.

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A chalcone glycoside was isolated from the flowers of six Corylopsis species, C. pauciflora, C. spicata, C. glabrescens, C. sinensis, C. gotoana, and C. coreana, and identified as chalcononaringenin 2'-O-glucoside by UV spectral survey, liquid chromatograph-mass spectrometry (LC-MS), acid hydrolysis, and characterization of its products, and direct thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) comparison with an authentic sample. Five flavonol glycosides, which were accompanied with chalcone glycoside, were also isolated and identified as quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, myricetin 3-O-rhamnoside, myricetin 3-O-glucoside, and kaempferol 3-O-rhamnoside in the same manner. Chalcone glycosides have been reported from various plant species, Dianthus, Coreopsis, Cosmos, Dahlia, and Bidens as yellow flower pigments. In this survey, it was shown for the first time that the yellow flower color of Corylopsis species is due to a chalcone glycoside, chalcononaringenin 2'-O-glucoside, but other flavonol glycosides hardly act as yellow pigments.

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