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

---

‘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

---

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)

---

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

望岡 亮介 山口 雅篤 堀内 昭作 松井 弘之 黒岡 浩

出版者

THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE

雑誌

園芸学会雑誌 (ISSN:00137626)

巻号頁・発行日

vol.64, no.3, pp.463-470, 1995 (Released:2008-05-15)

参考文献数

38

被引用文献数

7 7

---

日本原産野生ブドウを中心に, 5種, 5変種, 3未同定の東アジア原産野生種と, 対照として三つの栽培品種の果皮からアントシアニン色素を抽出し, HPLCを用いて色素分析した.色素の種類は, 得られたクロマトグラムと各ピークの積分値から5%以上を含有するもののみに限定した場合19種類の色素を認め, 種により3~15種類のアントシァニンが確認された. 特に, 北方系の野生種より南方系の野生種に含有色素の種類の多い傾向が認められた. また, ピークNo. 6は栽培品種では認められなかったが, 野生種では供試したすべてで確認された.アントシアニン組成の一致率によりクラスター分析を行ったところ, 形態的分類と比較的似通った結果となり, 本法は従来の形態的分類と併用すれば分類の精度をさらに高めることができるものと思われる. この方法で, チョウセンヤマブドウは他の野生種と明らかに区別できた. また, 本種およびその変種とされているシラガブドウのアントシアニン組成には大きな差異が認められ, 形態的•生理的観点と同様, 別種である可能性の高いことが確認された.

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

---

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

---

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

---

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

---

‘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

---

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)

---

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

---

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

---

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

---

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

---

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.

著者

Keigo Fukushima Shinji Kajihara Satoshi Ishikura Noritoshi Katsutani Tanjuro Goto

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-149, (Released:2018-02-08)

被引用文献数

2

---

This study was initiated to investigate the effects of wet treatment at 10°C (WT10°C) and subsequent re-drying treatment (RDT) on the germination and growth of Eustoma grandiflorum seeds. Both treatments, WT10°C and RDT, were applied at 10°C under dark conditions. In all the experiments, ‘King of Snow’, which is one of the major Eustoma cultivars in Japan, was used. When the total number of days exposed to WT10°C and RDT was set to 35 days, the prevention of rosettes and the promotion of growth were dependent on the number of days of WT10°C, and these effects were maintained after RDT. When RDT was applied to the seeds after WT10°C for 35 days, the growth promotion due to WT10°C was maintained regardless of the length of re-drying time from 7 to 28 days; however, the germination rate decreased with RDT. On the other hand, applying RDT after WT10°C for 14 days had no effect on the germination rate; however, the growth promotion was insufficient compared with WT10°C for 28 days. This problem was solved by carrying out a further 14 days of WT10°C after RDT. When the seeds were exposed to WT10°C for 14 days, then re-dried for 7 days, and exposed to WT10°C for a further 14 days, the same growth promotion was achieved as for seeds exposed to WT10°C for 28 days continuously. The above results suggest that the promotion of growth depends on the total number of days of WT10°C regardless of whether these days are continuous or not. Moreover, the growth promotion was maintained after RDT. The results also suggest the possibility that when both the processes of WT10°C and the RDT are carried out by seed companies, growers who have no cooling equipment can produce cut flowers using seedlings grown in the high-temperature season.

著者

Kenji Yamane Kitaro Sumida Yuri Terui Nagisa Kojima Chairat Burana Takeshi Kurokura

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-151, (Released:2018-02-08)

被引用文献数

2

---

Temperature regimes that cause malformed flowers were examined and histological observation was carried out at the developmental stage of flowers by using mutants of the potted carnation (Dianthus caryophyllus L.) ‘Cherry’ producing malformed flowers according to cultivation season. Plants of normal (WT) and malformed (mlf) lines were grown under several temperature regimes. All WT plants produced normal flowers, whereas mlf lines showed a variety of malformed floral phenotypes, including phyllody-like proliferated sepaloids, proliferated petaloids, proliferated pistillodes with or without petals, secondary flower formation, and a flattened receptacle. In Experiment 1, mlf plants produced no malformed flowers when grown under constant 26°C, whereas 34.2% of mlf plants produced malformed flowers at 14–16/12°C (day/night, natural light). Malformation frequency was slightly lower at a night temperature of 5°C compared with 14–16/12°C. When malformed mlf plants were transferred from 17/5°C to 23/18°C, flower malformation was alleviated. Conversely, when mlf plants grown under constant 26°C with a normal phenotype were transferred to 17/12°C, flower malformation was induced. Thus, flower malformation was reversible depending on the temperature regime. In Experiment 2, 92.2% of mlf plants produced malformed flowers under constant 15°C, whereas 3.1% and 1.3% showed flower malformation when grown under constant 20°C and 25/20°C, respectively. These findings suggested that the threshold for flower malformation is between 15°C and 20°C. Observation of shoot apices by optical microscopy and scanning electron microscopy revealed morphological differences between WT and mlf after sepal formation. Petal primordia were not visible in mlf plants at 15°C, although petal primordia were initiated in WT. After this stage, flower malformations observed in mlf included undeveloped petals, undeveloped or irregularly developed stamens, secondary flower primordia formation, and completely irregular arrangement of undeveloped flower organs. No phytoplasma was detected by PCR, indicating that it could not be the causal agent of the abnormal phenotypes. This is the first report of mutant flower phenotypes dependent on temperature and induced by only a 5°C difference within optimal growing-temperature regimes in carnations.

著者

Yusuke Kamiyoshihara Takuya Nakamura Yasuharu Itagaki Shinichi Asada Takashi Aoki Shinji Mizuno Keiichi Watanabe Hiroaki Inoue Akira Tateishi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-133, (Released:2018-02-01)

被引用文献数

2

---

Actinidin is a major protein contained in kiwifruit (Actinidia spp.). While uptake of actinidin is beneficial to help gastric protein digestion with cysteine protease activity, the protein is also recognized as a major elicitor of allergy which can induce tingling in the oral cavity and occasionally severe anaphylactic reactions. Given that consumption of fresh kiwifruit has increased globally, development of Actinidia cultivars with lower level of actinidin is required to reduce the risk of allergenicity. In the present study, we examined variations in the actinidin level in Actinidia varieties. Among several varieties having trace amounts of actinidin, A. chinensis ‘Kohi’ was targeted to be analyzed for the molecular basis for the phenotype. ‘Kohi’ had below the detectable transcript level of Act1a, a critical gene for actinidin level. The upstream region of Act1a in ‘Kohi’ constituted different sequences from that of A. deliciosa ‘Hayward’, which has an active promoter for high expression of Act1a. The ‘Kohi’ sequence in the diverged region (upstream from −873 b) was rich in cytosine residues methylated at a higher level than in ‘Hayward’. Our data suggest the possibility of novel epigenetic regulation to reduce the actinidin level. The molecular mechanism for the phenotype in ‘Kohi’ was differentiated from ‘Hort16A’, a globally popular cultivar with a low level of actinidin. This cultivar could be a choice as a genetic resource in breeding to develop cultivars with controlled actinidin levels.

著者

Soichiro Nishiyama Noriyuki Onoue Atsushi Kono Akihiko Sato Koichiro Ushijima Hisayo Yamane Ryutaro Tao Keizo Yonemori

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-140, (Released:2018-02-01)

被引用文献数

11

---

Persimmon (Diospyros kaki) is a tree crop species that originated in East Asia, consists mainly of hexaploid individuals (2n = 6x = 90) with some nonaploid individuals. One of the unique characteristics of persimmon is the continuous accumulation of proanthocyanidins (PAs) in its fruit until the middle of fruit development, resulting in a strong astringent taste even at commercial fruit maturity. Among persimmon cultivars, pollination-constant and non-astringent (PCNA) types cease PA accumulation in early fruit development and become non-astringent at commercial maturity. PCNA is an allelic trait to non-PCNA and is controlled by a single locus called the ASTRINGENCY (AST) locus. Previous segregation analyses indicated that the AST locus shows hexasomic inheritance; a recessive allele, ast, at this locus confers PCNA. Here, we report a shuttle mapping approach to delimit the AST locus region in the hexaploid persimmon genome by using D. lotus, a diploid relative of D. kaki, as a reference. A D. lotus F1 population of 333 individuals and 296 D. kaki siblings segregating for the PCNA trait were used to map the AST region using haplotype-specific markers covering the AST region. This indicated that the AST locus is syntenic to an approximately 915-kb region of the D. lotus genome. In this 915-kb region, we found several candidates for AST that were revealed from the fruit transcriptome of a population segregating for the PCNA trait. These results could provide important clues for the isolation of AST in hexaploid persimmon.

著者

Yusuke Kamiyoshihara Shinji Mizuno Mirai Azuma Fumika Miyohashi Makoto Yoshida Junko Matsuno Sho Takahashi Shin Abe Hajime Shiba Keiichi Watanabe Hiroaki Inoue Akira Tateishi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-142, (Released:2018-01-26)

被引用文献数

1

---

Avocado fruit ripen with ethylene production after harvest and the flesh becomes soft and edible due to degradation of cell wall polysaccharides during ripening. α-l-Arabinofuranosidase is a hydrolytic enzyme known to digest arabinose-containing cell wall polysaccharides. It has been shown that its activity increased with fruit ripening. However, our previous study showed that an α-l-arabinofuranosidase gene (PaArf/Xyl3A) is expressed in the avocado fruit before ethylene production. In addition, the transcripts were detected in some organs in which the level of ethylene was extremely low. These results indicate that the gene expression is independent of ethylene. In the present study, we carried out immunoblot analyses of α-l-arabinofuranosidase at the protein level. Using a polyclonal antibody raised against Japanese pear α-l-arabinofuranosidase, two α-l-arabinofuranosidase proteins with molecular masses of 72 kDa and 68 kDa, presumably belonging to glycoside hydrolase family 3, were detected in ripening avocado fruit. The protein levels in ethylene or 1-methylcyclopropene (1-MCP)-treated fruits were examined and the results indicated that the two proteins responded to ethylene in opposite ways; the 68 kDa protein showed a temporary accumulation, whereas the 72 kDa protein exhibited dissipation possibly caused by a loss of stability. The total enzyme activity of α-l-arabinofuranosidase was elevated faster in the ethylene-treated fruit throughout ripening and was slower in the 1-MCP-treated fruit, suggesting the existence of another α-l-arabinofuranosidase, which did not cross-react with the antibody and was positively regulated by ethylene, in ripening avocado fruit.

著者

Takanori Masukawa Masayuki Kadowaki Toshikazu Matsumoto Akira Nakatsuka Kyeong-Seong Cheon Kazuhisa Kato Fumi Tatsuzawa Nobuo Kobayashi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-132, (Released:2018-01-06)

被引用文献数

2

---

Purple and red colored root characteristics were introduced to a local pungent radish “Izumo orochi daikon” ‘Susanoo’, and several characteristics including food functional components were evaluated. The root and leaf phenotype, the pigment composition, the isothiocyanate and soluble solids contents, and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in the root were investigated. These characteristics were compared between the mass selection breeding lines of purple, red roots and their parent cultivars. Although one-third of individuals in the M6 and M7 were non colored, the colored root characteristics was introduced into ‘Susanoo’. The main anthocyanins in the deep reddish purple colored purple root lines were acylated cyanidin 3-sophoroside-5-glucosides, and those in the vivid purplish red colored red root lines were acylated pelargonidin 3-sophoroside-5-glucosides, which corresponded to the main anthocyanins in their respective colored root parental cultivars. The isothiocyanate contents in the purple and red root lines were almost the same as that in ‘Susanoo’. The DPPH radical scavenging activity of the purple and red root lines was almost two times higher than that of ‘Susanoo’. These results showed that the food functionality was enhanced by introduction of a colored root characteristic in ‘Susanoo’.