著者

Taku Yano Akiyoshi Morisaki Shun-ichiro Ito Masaharu Kitano

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-112, (Released:2018-07-21)

被引用文献数

2

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To predict the seasonal vegetative growth of potted seedlings of Satsuma mandarin, the effects of initial plant conditions (age, shoot pruning), environment (greenhouse, greenhouse + shading, open-field culture), and pot size on growth were researched for 1.5–2.5 years. The growth pattern was evaluated using a curve fitting with the 4-parameter logistic (4L) model, biomass allocation, and classical (interval) growth analysis, and a generalized linear model analysis based on thermal time (tt). Growth delays from shoot pruning were confirmed by growth trajectories with the 4L model based on tt. Plant growth was positively affected by enlarging the pot size (from 20-L to 45-L), while shading significantly suppressed the growth of 45-L potted Satsuma mandarin seedlings in the greenhouse. In the growth analysis, the relative growth rate was not always determined by the net assimilation rate (NAR), which included both shoot-pruning and pot size effects. To predict the plant mass of Satsuma mandarin seedlings (MP), we proposed several generalized linear models using a log link function assuming that MP followed a Gamma-distribution. The best model to predict MP was selected based on Akaike information criterion (AIC) values, and contained explanatory variables for initial plant biomass, NAR, specific leaf area (SLA), leaf mass ratio (LMR), pot size, and tt. Some simpler models excluding NAR, but including SLA and/or LMR as explanatory variables, were more useful than a model lacking growth analysis parameters (NAR, SLA, and LMR).

著者

Takashi Kawai Fumiya Matsumori Hidemi Akimoto Naoki Sakurai Ken Hirano Ryohei Nakano Fumio Fukuda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-012, (Released:2018-07-14)

被引用文献数

15

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Split pit in peach (Prunus persica (L.) Batsch) fruit is an internal disorder that can have adverse effects on fruit quality and shelf stability. As it is difficult to distinguish split-pit fruit from normal fruit by appearance, a nondestructive detection method is desirable to determine accurately the timing of split-pit occurrence and remove unwanted fruit from trees. In our recent study, we used an acoustic vibration method for the nondestructive detection of split pit in harvested peach fruit. Here, we demonstrate that this method can be used to detect split pit in unpicked peach fruit. Time-course monitoring of growing fruit revealed that the ratio of the third (f3) to the second (f2) resonant frequency (f3/f2), which is an indicator of split pit in harvested fruit, abruptly increased in unpicked split-pit fruit from early June to early July. In contrast, the f3/f2 values of normal fruit remained low until harvest in late July. The increase in f3/f2 values of split-pit fruit was observed in early June (stage II of fruit growth) and/or from late June to early July (stage III of fruit growth), suggesting that, at least under the experimental conditions in the current study, pit splitting occurred at these two different timings. Split-pit fruit detection rate at harvest increased towards the end of the second split-pit occurrence and split pit could be predicted with high accuracy thereafter. These results collectively suggested that the timing of split-pit occurrence in unpicked peach fruit could be predicted accurately by measuring f3/f2 values and unwanted fruit with split pit could be distinguished from normal fruit on trees. We discuss the possible applications of the nondestructive acoustic vibration method in combination with fruit thinning and the future use of this method in research aiming to develop effective prevention methods or resistant cultivars with reduced split pit.

著者

Yoshikuni Kitamura Takafumi Watanabe Yukari Kato WeiWei Teoh Keiko Kataoka Yuki Yamaguchi Tomohiro Haruta Hideo Nishioka Kiyokazu Kametani

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-003, (Released:2018-06-19)

被引用文献数

1

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Information about mechanical reinforcement of decorative organs could help development of a novel technique that would give flowers with robust floral organs and broadly contribute to postharvest flower preservation. Hydrangeas (Hydrangea spp.) exhibit remarkable characteristics in terms of mechanical reinforcement of decorative sepals. Although decorative sepals at the flowering stage shrink when they are desiccated, decorative sepals after flowering maintain their shape even after desiccation. In this study, the lignifications of the vein cells in decorative sepals were analyzed using phloroglucinol/HCl-staining. The microstructure of the cell wall was analyzed using transmission electron microscopy (TEM). The three-dimensional structure of vein cells was analyzed using serial block-face scanning electron microscopy (SBF-SEM). Tubular- and spindle-shaped dead cells with a lignified pitted secondary cell wall were observed around the vessel elements in decorative sepals after flowering. These cells were observed as living cells without a secondary cell wall in the veins of decorative sepals at flowering and in fully expanded leaves. Further, 10 hydrangea cultivars were analyzed for development of mechanical reinforcement in vein cells, and some of them were compared by desiccation testing. Decorative sepals of a cultivar lacking those cells exhibited shrinkage after flowering when they were desiccated. In conclusion, dead cells with a lignified pitted secondary cell wall contribute to the reinforcement of veins in decorative sepals of hydrangeas and become sclerified parenchyma cells. Axial parenchyma sclerifying in veins after flowering is essential for robust hydrangea floral organs and represent a new type of mechanical reinforcement tissue in plant decorative floral organs.

著者

Olga Tejeda-Sartorius Libia Iris Trejo-Téllez María de los Ángeles Aída Téllez-Velasco Fernando Carlos Gómez-Merino

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-148, (Released:2018-06-15)

被引用文献数

2

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We carried out a comparative study on the effect of mineral fertilizers and biofertilizers on the nutrient concentration of Laelia anceps Lindl. subsp. anceps (Orchidaceae) seedlings. The first nutrient solution (Min-Fert) was prepared with commercial mineral fertilizers (Peters Professional® 30N-10P-10K); the second one (Biofert) from Nutro® commercial biofertilizer; and the third with a combination of mineral sources and biofertilizers (Min-Fert + Biofert). Mineral fertilization promoted significant differences in N concentration in leaves and roots. Also, it increased K and the concentration of some micronutrients in the roots. The phosphorous concentration increased in pseudobulbs and roots with the Min-Fert and Min-Fert + Biofert. Biofertilization increased the N concentration in pseudobulbs, and Min-Fert + Biofert increased the Ca and Mg concentration in the roots, as well as the concentration of Fe and Cu in pseudobulbs and Cu in the leaves. Interestingly, Min-Fert significantly increased the nutrient concentration in the roots in comparison to the other tissues. We demonstrated that the use of biofertilizers in L. anceps subsp. anceps (alone or as a supplement to mineral fertilization), represents an alternative to reduce production costs and mitigate the negative impacts of mineral fertilization on the environment.

著者

Kaori Matsuoka Naoki Moritsuka Shinnosuke Kusaba Kiyoshi Hiraoka

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-167, (Released:2018-06-13)

被引用文献数

5

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In blueberry culture, when sulfur and NH4+ and K fertilizers are applied to soils, radiocesium in the soils may be released into the soil solution, absorbed by roots, and then translocated to fruit. We reanalyzed data from our previous experiment to evaluate soil factors affecting the concentration and total amount of natural stable Cs in blueberry organs and its translocation to fruit. During a 2-year pot experiment, 4-year-old rabbiteye blueberries (Vaccinium virgatum Aiton ‘Onslow’) were grown in three soils (Andosol, Cambisol, and Fluvisol) with or without soil treatment (acidification, NH4+ and K fertilization, or combined acidification-fertilization treatment). We measured the concentrations of 13 elements (N, Na, Mg, Al, P, K, Ca, Mn, Fe, Cu, Zn, Rb, and Cs) in samples of the soil solution and the blueberry fruit, leaves, branches and stems, and roots, as well as the pH of the soil solution. Acidification, fertilization, and combined treatment increased the Cs concentration in the soil solution within each soil. On the other hand, the Cs concentration in the whole bush was not changed significantly by any soil treatment. The Cs concentration in fruit, leaves, and branches and stems was significantly negatively correlated with concentrations of Na, Mg, K, and Ca in the soil solution. Among the three soils, the concentrations of these basic cations were lowest in the soil solution of the Cambisol. The fruit Cs concentration in the Cambisol did not change significantly with any soil treatments. In contrast, in the Andosol and Fluvisol, the fruit Cs concentration was significantly decreased by both acidification and fertilization. The whole-bush Cs content did not differ significantly among the soil treatments, whereas the percentages of Cs in fruit and roots depended greatly on the soil treatment within each soil, although the distribution trends relative to the control were opposite for fruit and roots. Our results suggested that the soil treatments to increase the concentrations of soil basic cations could reduce the rate of transfer of Cs to fruit and thereby contribute to a reduction in the Cs concentration in fruit, but not the whole-bush Cs content.

著者

Issei Asakura Yoichiro Hoshino

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-163, (Released:2018-05-22)

被引用文献数

3

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Actinidia kolomikta (Maxim. & Rupr.) Maxim., a wild kiwifruit relative native to East Asia, has several desirable characteristics, such as strong cold tolerance, precocity, and high levels of vitamin C, and has therefore attracted horticultural interest. In this study, the interspecific cross compatibility of the diploid Actinidia kolomikta with one cultivated species [A. deliciosa (A. Chev.) C. F. Liang & A. R. Ferguson], three native Actinidia species [A. arguta (Siebold & Zucc.) Planch. ex Miq., A. polygama (Siebold & Zucc.) Maxim., and A. rufa (Siebold & Zucc.) Planch. ex Miq.], and one endemic variety [A. arguta (Siebold & Zucc.) Planch. ex Miq. var. hypoleuca (Nakai) Kitam.], was evaluated to see if interspecific hybridization using A. kolomikta could improve edible Actinidia crop breeding programs. There was no fruit setting two weeks after anthesis in the tested cross combinations when A. kolomikta was the male parent. In contrast, all five crosses using A. kolomikta as the female parent produced 100% fruit setting two months after pollination. The crosses with different ploidy levels such as combinations between diploid A. kolomikta and hexaploid A. deliciosa, or diploid A. kolomikta and tetraploid A. arguta, produced a few viable seeds. In contrast, the crosses with diploid species such as A. arguta var. hypoleuca, A. polygama, and A. rufa, produced many viable seeds and seedlings. From these results, the cross compatibilities of A. kolomikta with the other tested species were categorized as follows: no fruit setting (A. arguta × A. kolomikta and A. polygama × A. kolomikta); fruit setting with few viable seeds (A. kolomikta × A. arguta and A. kolomikta × A. deliciosa); and normal fruit setting with viable seeds (A. kolomikta × A. arguta var. hypoleuca, A. kolomikta × A. polygama, and A. kolomikta × A. rufa). These results could be a basis for future edible Actinidia crop breeding programs using A. kolomikta and interspecific hybridization.

著者

Yoshikuni Kitamura Tetsuya Hattori Kaori Mogami Takashi Fudano Mariko Uehara

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-152, (Released:2018-04-25)

被引用文献数

2

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Hydrangea (Hydrangea spp.) flower buds usually differentiate from the end of summer through autumn, but some cultivars can also produce flower buds in spring. In the present study, we selected cultivars with high potential for such unseasonable flower bud production in Japan by evaluating the flower bud production on pinch-treatment-induced axillary shoots. We also examined the pinching time and the difference between the two shoot types: previously formed shoots that developed from buds formed in the previous autumn and basal shoots that formed in the current spring. We found that ‘Christmas’, ‘Endless Summer’, and ‘Rosea’ had the highest frequencies of unseasonable flower bud production on the axillary shoots of previously formed shoots (90.0%, 80.0%, and 90.0%, respectively) and basal shoots (90.0% for all three cultivars). When the buds were pinched in mid-April, the axillary shoots that formed on both shoot types flowered from early July to mid-August, which was approximately 1 month later than for seasonably produced flower buds in the same cultivars. In 2011, 98.0%, 90.5%, and 84.0% of the axillary shoots that developed on previously formed shoots flowered in ‘Christmas’, ‘Endless Summer’, and ‘Rosea’, respectively, while in 2012, 63.2%, 54.9%, and 75.3% flowered, respectively. Similar values were seen for the basal shoots, with the exception of ‘Christmas’ in 2011 and ‘Endless Summer’ in 2012, which both had lower flowering rates than previously formed shoots. In ‘Rosea’, flower bud differentiation started just after the pinch treatment, and the frequency of flower bud production decreased when the pinch treatment was conducted after late April. Thus, ‘Christmas’, ‘Endless Summer’, and ‘Rosea’ were considered to have high potential for unseasonable flowering following pinch treatment in early spring. However, unseasonable flower bud production may often be suppressed in pinched basal shoots.

著者

Oscar Witere Mitalo William Olubero Asiche Yuka Kasahara Yasuaki Tosa Willis Omondi Owino Eric Gituma Mworia Koichiro Ushijima Ryohei Nakano Yasutaka Kubo

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-035, (Released:2018-04-19)

被引用文献数

11

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‘Rainbow Red’ kiwifruit have been reported to gradually ripen during low temperature storage and on the vine in the absence of detectable ethylene. This study was conducted to compare the expression of ripening-related genes during storage at different temperatures and on the vine. Fruit at 5°C and 10°C ripened faster to eating quality within four weeks accompanied with increased expression of ripening-related genes: AcACO3, AcXET2, AcEXP1, AcPG, AcPMEi, AcSUS, AcβAMY1, AcβAMY2, AcGA2ox2, AcNAC3, AcNAC4, and AcMADS2. Fruit at 15°C required a longer period of eight weeks to attain eating quality in concurrence with delayed accumulation of the ripening-related genes. Fruit at 22°C ripened at the slowest rate and did not attain eating quality even after eight weeks, with very minimal accumulation of ripening-related genes. On-vine ripening occurred slowly at the early stages when the average field temperature was ~20°C, but the rate increased as the temperature dropped to ≤15°C accompanied by increased expression of ripening-related genes. These results indicate that both ripening on-vine and during low temperature storage are modulated by low temperature independent of ethylene.

著者

Ittetsu Yamaga Shigekazu Nakamura

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-147, (Released:2018-04-18)

被引用文献数

9

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In the present study, we examined the effect of blue LED irradiation on production of phytoalexin scoparone in wounded satsuma mandarin fruit as a result of fungal infections, as well as the effect of tape-type blue LED on fruit decay during long-term storage (from December to April) in an actual storage room. The blue LED treatment reduced the rate of fruit decay compared to that of dark treatment in wounded fruits. The decay rate of LED irradiated fruit was 13.3%, while that of non-irradiated fruit was 51.1%. In wounded fruits, blue LED treatment resulted in significantly higher scoparone contents than dark treatment. Intact (non-wounded) fruits had low scoparone contents, irrespective of blue LED irradiation. In an examination of changes in total fruit decay rate during storage using tape type-blue LED, the total decay rate was not significantly different between the LED-treated and untreated fruits until 64 days after storage (36 days after starting LED irradiation). On the other hand, at 92 and 120 days after the start of storage, total fruit decay under blue LED treatment was significantly lower compared to the untreated control. The tape-type blue LED (10 μmol·m−2·s−1) did not affect either the fruit quality analyzed (soluble solid content, titratable acidity, specific gravity, percentage of flesh) or the rind color. These results indicate that blue light induces scoparone production in wounded satsuma mandarin, and because of this, along with other putative factors, tape-type blue LED irradiation reduces mandarin fruit decay during long-term storage.

著者

Runch Tuntipaiboontana Chatuporn Kuleung Vipa Hongtrakul

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-128, (Released:2018-04-11)

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For their exceptional beauty and great variety, waterlilies of the genus Nymphaea are popular ornamental plants worldwide. To improve their appealing traits, breeders worldwide have attempted intrasubgeneric and intersubgeneric cross-breeding and succeeded in producing new varieties. Molecular markers have become standard practice in the breeding process and for accurate variety identification. With increasing knowledge about transposable elements in eukaryotic genomes, retrotransposon-based markers have been developed for various plant species and were sometimes found to be more informative than conventional marker methods. Due to the lack of information about retrotransposons in waterlilies, this study aimed to confirm the presence and analyze the diversity of the Ty1-copia retrotransposons, which have been well studied and used to develop markers in many plants. 133 sequences of a conserved domain in the reverse transcriptase gene of Ty1-copia elements were isolated from 13 varieties of waterlilies and found to be homologous to either Ale, Angela, or TAR lineages. Sequences homologous to the Ale lineage were found to be abundant and diverse. Those homologous to the Angela lineage were found to be very conserved, but scarce. Those homologous to the TAR lineage were relatively conserved and were found in ample amounts. Furthermore, the results indicate that those homologous to the Angela or TAR lineages are more conserved to their counterpart in other plants than those homologous to the Ale lineage. From this study, 3 groups of Ty1-copia elements were found to be suitable candidates for development of retrotransposon-based markers for waterlilies in the future.

著者

Yu Sung Shih-Wen Chen

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-083, (Released:2018-03-20)

被引用文献数

3

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Currently, biofortification breeding programs are being conducted to increase the selenium (Se) content of crops. Se is an element essential to humans and is mostly acquired via consumption of vegetables. However, the effects of Se on the main plant metabolisms such as nitrogen metabolism are unclear. The main objective of this study was to determine the effect of the application of different concentrations of Se (10, 20, and 30 μM) as Na2SeO4 on nitrogen metabolism in Pak-choi grown hydroponically. Supplemental Se increased all enzyme activities analyzed, including nitrate reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT). In 20-μM Se treatment of two cultivars, the fresh weight was significantly increased and the foliar NO3− content was significantly decreased. Compared to the control, the data on Se treatments showed stronger activations of NR, GS, and GOGAT, as well as greater concentrations of total ammonium, amino acid, and protein, and a higher nitrogen use efficiency, resulting in increased biomass production. This suggests the mechanism of Se applied to Pak-choi to decrease NO3− content was due to increasing nitrogen metabolism and protein synthesis to biomass.

著者

Ryuichi Suwa Hironori Tajima Shinichi Gima Naoko Uehara Kenta Watanabe Shin Yabuta Jun Tominaga Yoshinobu Kawamitsu

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-069, (Released:2018-03-13)

被引用文献数

8

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In Japan, several plant species have high commercial value because of their functional properties. In this study, we aimed to investigate the effects of soil type (red, dark-red, and gray soil) and growth stage (vegetative and reproductive) on the growth and polyphenol production (chlorogenic acid, rutin, hesperidin, and diosmin) of P. japonicum. Plants grown in gray soil had the heaviest dry weight, followed by those grown in dark-red soil. Flowering plants grown in gray soil had a polyphenol concentration lower than those grown in the other two soil types. However, differences in the concentration of polyphenols were even larger between the growth stages. During the flowering period, the concentration of polyphenols sharply increased in the stems. Additionally, the flowers contained relatively similar amounts of polyphenols to stems and leaves, accounting for approximately 1/4–1/2 of the net amount in the plant.

著者

Kazuhiro Matsumoto Toru Kobayashi Tomoaki Kougo Tomomichi Fujita Saki Sato Takaya Moriguchi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-120, (Released:2018-03-13)

被引用文献数

5

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We investigated the effect of fruit bagging treatment using three kinds of paper bags differing in light permeability on the red coloration of skin, flesh, and core in type 2 red-fleshed ‘Kurenainoyume’ apples by comparison with type 1 ‘Goshogawara’ apples. Skin coloration of both ‘Goshogawara’ and ‘Kurenainoyume’ was affected by light and the effect was more marked in ‘Kurenainoyume’ than ‘Goshogawara’. In contrast, the effect of fruit bagging treatment on the red coloration of the core was limited in ‘Goshogawara’, while core coloration was not observed in ‘Kurenainoyume’ type 2 apples. Flesh coloration was observed even under dark conditions in both cultivars, and the light tended to enhance the flesh coloration to some extent in both cultivars. Since fruit bagging treatment is a prerequisite for ‘Kurenainoyume’ to prevent cork spot-like physiological disorder (CSPD) in the skin, we optimized the fruit bagging treatment conditions using a light impermeable double-layered paper bag (2-layer bag), considering both prevention of CSPD and the red coloration of ‘Kurenainoyume’ skin and flesh. Bag-removal at 25, 35, and 45 days before harvest (DBH), resulted in good skin and flesh coloration without CSPD incidence. Moreover, there was no significant difference in fresh weight, soluble solid, or malic acid contents compared with the non-bagging control. Therefore, we recommend bag-removal from 25 to 45 DBH for ‘Kurenainoyume’ as a practical cultivation technique.

著者

Kazuhiro Matsumoto Tomomichi Fujita Saki Sato Takaya Moriguchi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-130, (Released:2018-03-13)

被引用文献数

9

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‘Kurenainoyume’ is a newly released type 2 red-fleshed apple with pinkish flesh color. In our previous study, we revealed the effects of light condition on red coloration of the skin, flesh, and core of ‘Kurenainoyume’ apple fruit. In this study, we investigated the effects of temperature, shading, defoliation, and crop load on red coloration of the flesh. Low temperature improved flesh coloration; apples subjected to cooling treatment at 5°C or 10°C showed higher a* values of the Lab color space than the control (without cooling treatment), in a temperature-dependent manner. Low temperature reduced the soluble solid content to a lesser extent in some years, whereas fresh weight, malic acid content, and flesh firmness were not affected. Thus, the importance of temperature for flesh coloration was confirmed, similar to its effect on skin coloration. When the trees were covered with cheesecloth with a 50% shading rate from August 1 (82 days after full bloom: DAFB) to October 28 (170 DAFB), flesh coloration was negatively affected, and fresh weight, soluble solid, and malic acid contents were reduced relative to the control treatment (without shading). We also investigated the effects of defoliation (one-seventh of the control) and crop load (two- or threefold the crop load of the normal case control) on flesh coloration. Both defoliation and over crop load also decreased a* values, but their effects on the parameters related to fruit quality were not clear. Because all the treatments of shading, defoliation, and crop load relate to the efficiency of photosynthesis and the distribution of photosynthetic assimilates, our results also demonstrated that photosynthetic assimilates (carbohydrates) were one of the crucial factors affecting flesh coloration.

著者

Manato Ohishi-Yamazaki Miho Watanabe Ai Nakanishi Jingai Che Naomi Horiuchi Isao Ogiwara

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-136, (Released:2018-03-13)

被引用文献数

5

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We attempted to shorten the juvenile phase of southern highbush blueberries by using controlled rooms under artificial light. Seeds were extracted from fresh fruits and sowed in the Woody Plant Medium (WPM) immediately after harvest. When these seeds were irradiated with red LED, their germination rate was over 80% by the 35 days after sowing. The seedlings in the controlled room continued to grow without entering the dormant phase. Especially, maximum growth was observed under the long-day condition of 12-h light. Even under the short-day condition of 8-h light, increased growth was observed when grown at a high light intensity (400 μmol·m−2·s−1). For the seedlings that were moved from the long-day controlled room to the short-day controlled room after 10 months, the ‘Misty’ seedlings flowered within 327 days after sowing while the ‘Sharpblue’ seedlings flowered within 357 days after sowing. Furthermore, when cultivated under the short-day condition at 400 μmol·m−2·s−1 for the entire length of the experiment, the flowering of ‘Misty’ seedlings was observed within 300 days after sowing. The seedlings maintained under the short day condition of high light intensity flowered earlier than seedlings moved from the long-day controlled room to the short-day controlled room. Thus, southern highbush blueberries were successfully induced to flower in less than a year from seed planting, using a combination of techniques to promote germination and control the growth environment conditions in a controlled room.

著者

Masashi Yamamoto Yuta Natori Kei Kawai

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-162, (Released:2018-03-13)

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An investigation of local citrus genetic resources grown on the Chuuk Islands of the Federated States of Micronesia was conducted in August 2013. A total of 21 accessions were examined. According to the morphological traits, ten, four, four, two, and one accession resembled lime (local name “Nayimis”), sour orange (“Kurukur”), calamondin (“Tangerin” and “Gunkan”), sweet orange (“Kurukur” and “American Kurukur”), and pummelo (“Kurukur”), respectively. Next, cleaved amplified polymorphic sequence (CAPS) analysis was conducted. Then, precise accession identification was made based on the results of CAPS analysis in conjunction with morphological traits. “Nayimis” accessions were classified into at least two types. Genotypes of “Nayimis” type 1 were identical to those of Mexican lime. A genetic influence from mandarin was detected in “Nayimis” type 2. Although the morphological traits of all “Kurukur” sour orange types were similar, their diversity was revealed by CAPS analysis. The genotype of one “Kurukur” accession was identical to that of sour orange. Genotypes of the sweet orange-type “Kurukur” and “American Kurukur” were different. The types of “American Kurukur” and sweet orange were the same. Pummelo-type “Kurukur” was considered to be true pummelo based on the results of morphological and molecular markers. Morphologically, the calamondin-like accessions “Tangerin” and “Gunkan” showed the same genotype combinations on CAPS analysis. These genotypes were identical to those of calamondin used as a control. The combined results of morphological and molecular markers offer valuable information for the identification of citrus genetic resources on the Chuuk Islands.

著者

Chikako Honda Shigeki Moriya

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-R01, (Released:2018-03-13)

被引用文献数

64

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Anthocyanin accumulation is responsible for the red color of the skin and flesh of apple fruits (Malus × domestica Borkh.), and redder fruits are more marketable. Pigmentation in the skin of apple fruit varies among different cultivars and is influenced by environmental factors, including temperature conditions and the level of sunlight irradiation. Because warmer temperatures suppress anthocyanin synthesis in the skin of apple fruit, there are increasing concerns that global warming may be detrimental to fruit pigmentation. Recent molecular studies have revealed that the MdMYB1 gene, which encodes a transcription factor, plays a critical role in regulating anthocyanin synthesis in both the skin and flesh of apple fruits. A marker-assisted selection process has been developed to identify MdMYB1 genotypes and predict those fruits that will develop redder skin. These apples may be better adapted to a warmer global climate. The application of hormones can also increase the level of pigmentation in fruit skin, and plant growth regulators such as ethylene and jasmonate are commercially available. The mechanisms that regulate anthocyanin biosynthesis in the flesh of red-fleshed apple fruit appear to partially differ from those that function in the skin of red-skinned fruit. In the flesh of red-fleshed fruit, the pigment accumulates under dark conditions, whereas no anthocyanin is synthesized in the skin of bagged apple fruit. Conversely, in both red-skinned and red-fleshed apple fruits, warmer temperatures inhibit anthocyanin accumulation. Further studies on the regulation of anthocyanin synthesis in the flesh of red-fleshed apple fruit are necessary.

著者

Kyoko Kawakatsu Taro Harada Ayuko Ushio Mitsuru Dozono Naoko Fukuta

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-138, (Released:2018-02-17)

被引用文献数

5

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The number of petals in a flower is one of the most important appearance qualities of ornamental flowers. In Eustoma, the number of petals fluctuates significantly and little is known about how it is controlled. We investigated the cultivating conditions that affect the number of petals in double flowers and tried to develop a technique for growing splendid corolla. High temperature in the reproductive phase reduces the number of petals. The transient treatment of high temperature just prior to the petal initiation stage is sufficient to control such a reduction. The measurement of flower bud growth showed that one week of temperature treatment is necessary to control the number of petals in a flower. The integration of our results demonstrated that both daytime and nighttime temperatures affected the number of petals and that the number of petals was clearly correlated with average daily temperature within the range of 20°C < x < 25°C. This phenomenon applies to various cultivars in Eustoma grandiflorum. We propose the greenhouse conditions necessary to achieve both high quality flowers and reduced energy consumption by considering the temperature and stages of flower development.

著者

Moalla Rached Baldet Pierre Gibon Yves Chiaki Matsukura Toru Ariizumi Hiroshi Ezura Naoya Fukuda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-150, (Released:2018-02-16)

被引用文献数

14

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Calcium is widely accepted as the main factor responsible for blossom-end rot (BER) appearance in tomato (Solanum lycopersicum L.) fruit. However, reactive oxygen species (ROS), which can damage plant tissues have also been proposed to initiate BER appearance in tomatoes and other fruit-bearing vegetables. Ascorbate, the major antioxidant in tomato fruit, is generally lower during green fruit development, which corresponds to the stage of BER appearance. Accordingly, one hypothesis is that tomato cultivars with a lower susceptibility to BER under salt stress have higher ascorbate contents and thus better control of ROS levels. In this study, to clarify the relationship between BER incidence and oxidative stress, two BER resistant cultivars, ‘Managua RZ’ and ‘House Momotaro’ and one BER-susceptible cultivar ‘Reiyoh’, were cultivated under salinity or standard nutrient solution (control) conditions. Calcium, potassium, magnesium, total hydro-soluble antioxidants, and ascorbate concentrations were measured in the distal pericarp 1 to 2 days prior to symptom appearance and during symptom appearance in healthy and affected fruits. When salt stress was applied, only BER-resistant cultivars showed a significant increase in ascorbate contents prior to BER appearance as compared with their levels under the control condition. In contrast, pre-BER Ca2+ concentrations did not associate with the BER susceptibility of each cultivar. Interestingly, ‘Reiyoh’ showed much higher K+/Ca2+ and (K++Mg2+)/Ca2+ ratios than the two other cultivars in healthy fruits due to a strong tendency towards lowered Ca2+ concentrations. A similar tendency was also observed in apple “bitter pit”. The ability to increase the fruit antioxidant capacity and maintain mineral balance under salt stress conditions may explain the resistance to BER development in highly resistant cultivars, probably by the avoidance of oxidative-induced cell necrosis and stabilization of the cell membranes, respectively.

著者

Yoshitaka Kawai Tadashi Baba Mika Yoshida Josephine U. Agravante Dormita R. Del Carmen

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-145, (Released:2018-02-08)

被引用文献数

3

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In harvested calamondin fruit, the effects of benzyladenine (BA) and light on the rind color and fruit quality were investigated. BA application delayed degreening of the calamondin fruit in both light and dark conditions. At 5 days, BA application had no influence on total soluble solids (TSS), titratable acid (TA), sugar contents, ascorbic acid (AA), and organic acid in the fruit juice and at 9 days, only AA content has decreased in BA-treated fruits. Light promoted quick degreening of calamondin fruit, whereas in the dark, degreening had proceeded very little in un-treated fruit at 9 days. Light did not influence fruit quality at 5 days either. However, light influenced the sugar content, especially increasing glucose and total sugar, as well as AA content in fruit at 9 days. Concerning the AA content in calamondin fruit, BA decreased and light increased it. These results indicated that BA treatment after harvest and maintaining fruit in the dark are sufficient to retain the green rind color of harvested calamondin fruit without affecting fruit quality, except for AA content.