Anthocyanins, which contribute red coloration to apple skin, are recognized for their antioxidant properties. Some apple cultivars also accumulate anthocyanins in fruit flesh. In this study, we analyzed the inheritance of coloration traits in fruit skin, fruit flesh, and leaves as well as their candidate gene, and searched for quantitative trait loci (QTLs) for fruit maturity linked to the red flesh trait in ‘Maypole’, using a ‘Fuji’ × ‘Maypole’ F₁ population. Phenotypic segregation in the F₁ population indicated that red skin, striped skin, red flesh, and red leaf traits are each controlled by separate single dominant genes and that red leaves co-segregated with red flesh. Of these, a striped skin trait derived from ‘Fuji’ corresponded to the MdMYBA genotype, known to regulate anthocyanin synthesis in fruit skin, suggesting that this genotype may be responsible for fruit skin coloring patterns. The red leaf/red flesh trait derived from ‘Maypole’ co-segregated with the MdMYB10 R6 promoter. MdMYBA and MdMYB10 were located in the same region at the bottom of linkage group (LG) 9 on the same genetic material, supporting that these genes are allelic. Analysis of the relationship between red coloration and fruit maturity revealed that fruits of red-fleshed progeny tended to mature earlier than those of white-fleshed progeny. A major QTL accounting for 35.6% of the total variance (logarithm of odds [LOD] = 8.94) was detected near the MdMYB10 locus in ‘Maypole’, indicating that the factor controlling earliness of fruit maturity is tightly linked to the red leaf/red flesh trait.

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The diversity of chloroplast DNA (cpDNA) of citrus was revealed by means of a cleaved amplified polymorphic sequence (CAPS) using 97 Citrus, including many local accessions from Japan, China, and Indonesia, four Fortunella, and two Poncirus. All accessions were classified into seven types based on the results of polymorphic bands in all primer/enzyme combinations. The seven types were identified as follows: Type 1 (38 accessions): C. macroptera, C. hystrix, C. aurantifolia, C. medica, C. limon, C. grandis, C. aurantium, C. myrtifolia, C. bergamia, C. rokugatsu, C. sinensis, C. sphaerocarpa, C. nobilis (Kunenbo), C. keraji, C. oto, C. tarogayo, C. suavissima, mandarins of Yunnan and Guangxi, China, miscellaneous of Yunnan, China, C. madurensis, and Fortunella; Type 2 (one accession): C. latipes; Type 3 (two accessions): C. ichangensis and C. junos; Type 4 (six accessions): C. tachibana and C. depressa; Type 5 (18 accessions): C. jambhiri, C. tankan, C. sunki, C. reshni, C. depressa, mandarins of Kagoshima, Japan and Yunnan and Guangxi, China; Type 6 (36 accessions): C. nobilis (King), C. unshiu, C. reticulata, C. genshokan, C. clementina, C. succosa, C. suhuensis, C. tardiferax, C. erythora, C. kinokuni, C. oleocarpa, C. leiocarpa, mandarins of Kagoshima, Japan, Guangxi, Zejiang, Yunnan and Guangdone, China, and mandarins of West Sumatra, Indonesia; Type 7 (Two accessions): Poncirus. The differentiation of cpDNA in citrus was discussed in accordance with the results.

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To establish better embryo induction procedures in anther culture of apple, the relationships between the microspore stage and the flower bud stage, and between embryo induction and the developmental stage of microspores during cold pre-treatment of flower buds were investigated. We classified the flower bud stages into four: “Tight cluster”, “First pink”, “Pink”, and “Full pink”. Each stage was defined by a morphological characteristic. The microspore stages were classified into seven: “tetrads”, “early uninucleate”, “mid-uninucleate”, “late uninucleate”, “early binucleate”, “late binucleate”, and “mature grain”. The morphological characteristic in each stage was clarified. The “Tight cluster” flower bud stage mainly corresponded with the microspore stage of tetrad to mid-uninucleate. The “First pink” of the flower cluster mainly corresponded with the mid-uninucleate and late uninucleate microspore. The “Pink” and “Full pink” of flowering corresponded respectively with the late binucleate and the mature grain. Cold pre-treatment for more than 25 days of flower buds was found to be an efficient means of increasing embryo formation in anther culture. The microspore of late uninucleate and early binucleate stages grew into embryos efficiently after 25 days of cold pre-treatment. To achieve that condition, flower buds at late “Tight cluster” to early “First pink” stage were collected because the microspore stage progresses during 25 days of cold pre-treatment. Most microspores were early uninucleate to early binucleate stages at the “Tight cluster” to “First pink” flower bud stages. The shoots regenerated from embryos were analyzed using SSR markers. The investigation revealed that all shoots had a haploid origin.

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To determine the relationship among wild grape species and grape cultivars, genotyping with 8 SSR loci was carried out using a wide range of grape species and cultivars, i.e., North American species, East Asian species, cultivars of Vitis vinifera, and those of V. vinifera × V. labrusca. SSR genotyping showed that wild grape species are more highly diverse than cultivated grapes. Principal coordinate analysis based on the distance (1-proportion of shared alleles) among accessions showed a clear separation between wild and cultivated grapes. A native Japanese cultivar, ‘Koshu’, and a Chinese cultivar, ‘Niunai’, were plotted among the cultivars of V. vinifera, even though these two Far East cultivars have some unique alleles.

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The genetic variation of loquat (Eriobotrya japonica (Thunb.) Lindl.) was characterized by SSR markers developed from apple and pear, using 94 loquat accessions in Japan. Fourteen of the 24 SSR markers derived from apple could successfully produce amplified bands in loquat, whereas 10 of the 24 SSR markers derived from pear could generate amplified bands. Nine SSR markers were chosen for evaluation of the genetic diversity among 94 loquat accessions, including 61 cultivars from Japan and other countries and 33 natively grown accessions collected around Japan. A phenogram constructed using the unweighted pair-group method with arithmetic averages based on similarities between genotypes revealed two major groups. One group consisted mainly of cultivars from Japan and other countries, whereas the other group included only natively grown accessions. Some synonyms or mutants were found showing identical SSR genotypes. These results show that SSR markers can be utilized as reliable tools for genetic identification in loquat. The origins of current loquat cultivars in Japan are also discussed.

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The possibility of summer harvest of white spears from asparagus (Asparagus officinalis L.) rootstocks stored in snow cover or a snow mound was examined over two seasons, in 2008–2009 and 2009–2010 experiments, respectively. One-year-old rootstocks were dug up on November 6 and November 12 in 2008 and 2009, respectively. Medium-sized rootstocks were put into the soil in containers and stored under natural snow cover or a snow mound for about 7 months. After snow storage, sugar content of the storage root was measured and containers with rootstocks were transferred to a dark room at 20°C to examine white spear yield. Rootstocks were stably stored at 0–1°C when they were fully covered with an adequate amount of snow. In both years, the total sugar contents in storage roots of rootstocks tended to decrease as the storage duration increased. Spear yield in summer harvest after more than 6 months of storage under snow tended to be lower than in winter harvest after 0 or 1.5 months of storage. Total sugar contents in storage roots during storage might greatly affect the spear yield of rootstocks. The marketable spear yield from one-year-old rootstocks with about 900 g fresh weight stored for more than 6.5 months under a snow mound was more than 190 g per rootstock in both years. Such a spear yield suggests that white asparagus spears can be commercially produced in summer from one-year-old rootstocks stored under a snow mound, a simple and low carbon system.

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Most modern carnation (Dianthus caryophyllus L.) cultivars have weak fragrances dominated by the scent of methyl benzoate. Wild Dianthus species with strong or unique scents may be useful gene resources for the improvement of carnation fragrances. We investigated the scents of interspecific hybrids between carnations and fragrant wild species by gas chromatography-mass spectrometry (GC-MS), and evaluated the usefulness of wild species for fragrant breeding in carnations. Dianthus hungaricus, which produced large amounts of various benzenoids, was crossed with a carnation with a floral scent dominated by methyl benzoate, but benzenoid diversity was not increased in the interspecific hybrid. We also analyzed some existing interspecific hybrids. Dianthus superbus var. longicalycinus had high amounts of β-ocimene and β-caryophyllene. These terpenoids were acquired as principal scent compounds by some interspecific hybrids between this species and a carnation lacking terpenoids. Three unidentified wild species (Dianthus sp. 4, 5, and 6) emitted high amounts of benzenoids, including eugenol, benzyl alcohol, methyl o-anisate, and methyl salicylate. These benzenoids were also detected in interspecific hybrids between carnations and the wild species, and the amounts were increased compared to the parental carnation. The emission of these scent compounds of wild Dianthus species was inherited by most hybrids lines; the variety and amounts of scent compounds tended to increase compared to parental carnations, although there was no general hereditary pattern. As we actually sensed the fragrances of the principal compounds from some hybrid flowers, the usefulness of interspecific hybridizations for the improvement of flower fragrances was confirmed. Dianthus superbus var. longicalycinus and Dianthus sp. 4, 5, and 6 seemed promising resources regarding the addition of terpenoids and the increase in benzenoid variation in the floral volatiles of carnations.

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Flower opening is important for floricultural crops. The mechanisms flower opening associated with the expansion of petal cells were investigated in Eustoma grandiflorum (Raf.) Shinn. Eustoma petals showed marked changes in their fresh weight, shape, and color during flower opening. Concurrently, petal cell-wall extensibility increased. This suggests that petal growth through flower opening is mainly caused by cell expansion. Expansin and xyloglucan endotransglycosylase/hydrolase (XTH) are known as representative proteins that loosen cell walls in plants. Three expansins and one XTH gene were isolated from opening Eustoma petals. We monitored for the first changes in their protein abundance in growing petals by Western blot analysis using antibodies to specifically detect expansin or XTH. The accumulation of these proteins marked the highest amount in petals when the flower was blooming and the petals were bending outwards. Thus, we showed that expansins participate in continuous petal growth from bud to opening flower and XTH plays a role in rapid petal growth accompanied by dynamic changes in petal fresh weight and petal shape.

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The cuticle, composed of cutin and associated waxes, probably acts as a barrier against water evaporation from the epidermal surface of flower petals. Cuticle formation begins with the biosynthesis of very-long-chain fatty acids (VLCFAs), catalyzed by a fatty acid elongase complex in epidermal cells. In the present study, cDNAs were cloned and analyzed for three enzymes (DcKCR1, DcHCD1, and DcECR1). Combined with the previously obtained cDNA for DcKCS1, the present study completes the identification of cDNAs for the fatty acid elongase complex in ‘Light Pink Barbara’ carnation for the first time. DcKCS1 transcripts were accumulated at flower opening stage (Os) 2 through Os 6 (full opening stage) with slight changes, but decreased markedly at senescence stage (Ss) 2 and Ss 4. Also, transcripts for DcKCR1, DcHCD1, and DcECR1 were present in considerable amounts during flower opening stages from Os 2 to Os 6. These findings suggested that the expressions of four genes are active during flower opening stage, which is concomitant with the expansion growth in petals requiring rapid formation of a waxy cuticle. Cut flowers of ‘Miracle Rouge’ carnation have an extremely long vase-life of about three weeks. The cuticle layer on the epidermal cells of ‘Miracle Rouge’ petals was thinner than that of ‘Light Pink Barbara’ petals, and ‘Miracle Rouge’ flowers had a depressed expression of DcKCS1, DcKCR1, and DcHCD1 in petals. These findings suggested that the prolonged vase-life of ‘Miracle Rouge’ flowers is not related to cuticle formation.

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Color perception of cut flowers may change depending on the light environment. We investigated how florist shop lighting changed the color perception of six cut rose colors (white, red, orange, yellow, purple, and red-purple) through visual color measurements. Visual color measurements were performed by expert colorists using the Commission International de l’Eclairage (CIE) colorimetry method. 6500 K (control), 3500 K, and 2800 K fluorescent lamps, and 6500 K LED lamps were used for comparison. Color perceptions changed depending on lamps and rose colors. When compared with control 6500 K fluorescent lamps, 2800 K fluorescent lamps induced high color differences (ΔE > 10) in all rose colors except white roses. 3500 K plant-growth lamps greatly altered purple rose color perception (ΔE > 34). 6500 K LED lamps had the lowest ΔE on average among the test lamps. Changes in color perception of red, orange, and yellow roses were influenced more strongly by 6500 K LED lamps than 2800 K lamps, probably due to the narrower spectrum of LED lamps. White lamps most closely replicating natural daylight should be considered as part of a florist shop lighting plan in order to accurately represent the various colors of flowers.

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We investigated ethylene production, ethylene biosynthesis genes, and senescence-related genes in flowers of a carnation (Dianthus caryophyllus L.) cultivar ‘Miracle Symphony’ (MS) and lines 006-13 and 62-2, which have a longer vase life than flowers of ‘White Sim’ (WS). WS flowers showed typical symptoms of senescence, but flowers of MS, 006-13, and 62-2 did not show symptoms of senescence, although they showed differences in vase life and ethylene production by day 15. The flowers of 006-13 and 62-2 produced small amounts of ethylene as a result of the low expression of two ethylene biosynthesis genes, DcACS1 and DcACO1; those of MS produced extremely low levels of ethylene. By day 15, the flowers of 006-13 and 62-2 showed increased expression of some senescence-related genes (DcCP1, DcbGal, DcGST1, and DcLip) that were upregulated by exogenous ethylene, indicating that a low level of ethylene production could induce the senescence of petals. In contrast to the upregulation of these senescence-related genes, the expression of DcCPIn, which was downregulated by exogenous ethylene decreased in petals of MS, 006-13, and 62-2 during flower senescence and was the same in all three lines at day 15. The results suggest that extended vase life depends on reduced levels of ethylene production, ethylene biosynthesis gene expression, and senescence-related gene expression.

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