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

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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

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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

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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

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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

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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

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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’.

著者

Tomoki Shibuya Yuki Murakawa Koji Nishidate Manabu Nishiyama Yoshinori Kanayama

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

vol.86, no.1, pp.94-104, 2017 (Released:2017-01-31)

参考文献数

36

被引用文献数

6

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切り花類の開花調節において発光ダイオードを効率的に利用するためには,単色光に対する花成や花成関連遺伝子の応答について良く理解することが必要である.長日性切り花類の花成の遠赤色光に対する応答はよく研究されているが,青色光に関する知見は少ない.すでに,長日性切り花であるシュッコンカスミソウ(Gypsophila paniculata)‘ブリストルフェアリー’の花成や FLOWERING LOCUS T と SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 のホモログである GpFT と GpSOC1 の発現が,青色光による長日処理では促進されないことが明らかとなっている.本研究では,シュッコンカスミソウ‘ミリオンスター’の花成が青色光による長日処理によって促進されたことから,シュッコンカスミソウにおいて青色光による花成応答の多様性が示唆された.そこでさらに,青色光で花成が促進された上記品種を使用し,GpFT と GpSOC1 の発現を調査した.その結果,‘ミリオンスター’の GpFT と GpSOC1 の発現は‘ブリストルフェアリー’と異なり青色光によって促進された.次に,青色光に対する花成応答に関与すると考えられる FLAVIN-BINDING KELCH REPEAT F-BOX 1 と GIGANTEA のシュッコンカスミソウホモログである GpFKF1 と GpGI を解析した.その結果,GpFKF1 と GpGI のアミノ酸配列は良く保存されており,その発現はシロイヌナズナと同様に短日と長日で異なるピークをもつ日周変動を示すこと,さらには GpFKF1 と GpGI が相互作用することが明らかとなった.一方,‘ブリストルフェアリー’と‘ミリオンスター’の 2 品種間において GpFKF1 および GpGI のアミノ酸配列には重要な違いはみられなかった.以上の結果,青色光応答の多様性は GpFKF1 および GpGI よりも GpFT および GpSOC1 に関連していることが示唆された.

著者

Shigeto Morita So Sugiyama Yoshihiro Nomura Takehiro Masumura Shigeru Satoh

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

vol.86, no.4, pp.519-527, 2017 (Released:2017-10-25)

参考文献数

35

被引用文献数

3

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2,4-Pyridinedicarboxylic acid (2,4-PDCA) extends the vase life of cut flowers of spray-type carnations by accelerating flower opening as well as retarding senescence. Since 2,4-PDCA can inhibit 2-oxoglutarate-dependent dioxygenases, which include enzymes for gibberellin (GA) biosynthesis and catabolism, we hypothesized that GA might be involved in the enhancing effect of 2,4-PDCA on the flower opening of carnation. In this study, we tested this possibility by examining the changes in gene expression of DELLA protein (GAI), a negative regulator of GA signaling, and GA levels in carnation (Dianthus caryophyllus L. ‘Light Pink Barbara (LPB)’) flowers treated with 2,4-PDCA. We also analyzed the expression of cell expansion-related genes, xyloglucan endotransglucosylase/hydrolase (XTH), and expansin genes as markers of flower opening in the treated flowers. The transcript level of GAI gene was increased, whereas that of expansin was decreased, in petals of the 2,4-PDCA-treated flowers compared to those of the control, which was contrary to the enhancement of flower opening. Our results suggest that the changes in the expression of these genes are not associated with the enhancing effects of 2,4-PDCA. In addition, GA3 content tended to be decreased by 2,4-PDCA treatment in the petals of opening flowers. Flower opening was not accelerated, but rather delayed, by treatment of flower buds with exogenous GA3 and not affected by paclobutrazol, an inhibitor of GA biosynthesis, in ‘LPB’ carnation. These results suggest that endogenous GA is not associated with the enhancement of flower opening by 2,4-PDCA in carnation.

著者

Yong Ha Rhie Seonghwan Kang Dong Chan Kim Jongyun Kim

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-131, (Released:2017-12-27)

被引用文献数

3

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Improving water use and nutrient efficiency can play a pivotal role in ensuring sustainable production of horticultural crops. This study aimed to investigate the optimum moisture level that best management practices need to ensure for high-quality garden mum production, and also determine the feasibility of using a soil moisture sensor-based automated fertigation system for water and nutrient management for high-quality garden mum production. We used 20 5TE (Decagon Devices, Pullman, WA, USA) sensors to monitor and control fertigation based either on the substrate volumetric water content (θ, v/v) at 0.25, 0.35, 0.45, and 0.55 m3·m−3, or conventional greenhouse management culture practices. At harvest, most vegetative growth parameters were not significantly different across the treatments, but the leaf relative water content of plants under the 0.25 m3·m−3 treatment was lower than that of plants under other treatments, indicating that the plants were drought stressed. Although flower diameters and peduncle lengths were similar across the treatments, the number of flowers of plants under the 0.25 and 0.35 m3·m−3 treatments were 25–37% less compared to that of plants under the 0.45 and 0.55 m3·m−3 treatments, and the conventional culture practice, which suggested decreased quality of garden mums under water stress. Water savings without a decrease in product quality by adopting the automated fertigation system with the threshold θ values of 0.45 and 0.55 m3·m−3 were 34.2% and 42.7% of the conventional cultural practice, respectively. The soil moisture sensor-based automated fertigation system can therefore save a considerable amount of water and fertilizer and ensure efficient water and nutrient management for practical production of high-quality garden mums.

著者

Yoshinori Kanayama Michiaki Omura Takeshi Goryo Tomohisa Shigeta Tomoki Shibuya Yutaka Nakai

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-109, (Released:2017-12-20)

被引用文献数

2

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Brassica napus was cultivated in three test fields exposed to different radionuclide contamination levels 1.5 years after the Fukushima Daiichi nuclear power plant accident to investigate the correlation between soil contamination and radiocesium activity concentration (RCs conc.) in plants. The correlations between total and exchangeable RCs conc. were strong in the plow layer (L1) and the layer 5 cm below L1 (L2). Water-soluble radiocesium was not detected in either layer, and little radiocesium penetration was observed below L2. Correlation coefficients between RCs conc. in each plant organ and soil layers were calculated. Correlations between RCs conc. in each vegetative organ and total and exchangeable RCs conc. in L1 and correlations between vegetative organs were mostly strong during vegetative growth and flowering periods. Correlations between RCs conc. in flowers with that in L1, L2, and other vegetative organs were not significant. RCs conc. in L1 may more directly affect concentrations in roots and shoots. RCs conc. in oil extracted from seeds was measured, and the results suggested that radiocesium was not detectable in the oil fraction. Our data regarding radiocesium in soil and plants and their correlations obtained by extensive cultivation in contaminated soils could be useful to gain a better scientific understanding of radiocesium transport and accumulation and to provide useful information for the future utilization of areas with low contamination levels.

著者

Yoshikuni Kitamura Sachiyo Ueno Hiroe Aizawa WeiWei Teoh

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-111, (Released:2017-12-20)

被引用文献数

5

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Two types of cut hydrangea flowers are marketed: Fresh-stage cut flowers (harvested just after the decorative sepals are completely colored before or during flowering) and antique-stage cut flowers (harvested when the decorative sepals become green and/or red after flowering). We investigated the differences in vase lives between fresh- and antique-stage cut flowers using 10 cultivars and 5 lines of hydrangea. The antique-stage cut flowers of ‘Endless Summer’, ‘Glowing Alps’, ‘Grünherz’, ‘Masja’, ‘Temari Ezo’, and line No. 2 exhibited significantly longer vase lives than their fresh-stage cut flowers. The difference in vase lives between the cut flowers of ‘Masja’ harvested at two different stages was approximately 60 days. We conducted further studies to elucidate the contribution of detailed differences in the harvest stages to differences in the vase lives using ‘Masja’ and ‘Xi’an’. Vase lives were compared among the cut flowers harvested at four different harvest stages that were divided based on flowering of florets and greening of the decorative sepals. The cut flowers of ‘Xi’an’ harvested at the decorative florets flowering- and decorative sepal greening-stages showed significantly longer vase lives than those harvested at the non-decorative floret flowering stage. The cut flowers of ‘Masja’ harvested at two harvest stages following the beginning of the decorative sepal greening stage exhibited significantly longer vase lives than those harvested at the other two harvest stages. A recutting treatment rescued the cut flowers harvested at the decorative sepal greening completed-stages that exhibited softening of the decorative sepals. This result suggested that the vase lives of cut hydrangea flowers were terminated by the disruption of water balance caused by vessel occlusion in the stem ends. In conclusion, a relatively longer vase life can be expected when cut hydrangea flowers are harvested after flowering of the decorative florets. However, we should note that cut flowers of some cultivars harvested at the decorative floret flowering stage may exhibit relatively short vase lives. Treatments that suppress vessel occlusion may be effective for lengthening the vase lives of cut hydrangea flowers.

著者

Sota Koeda Kanami Homma Yuri Tanaka Daiki Onizaki Elly Kesumawati Sabaruddin Zakaria Shinya Kanzaki

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-137, (Released:2017-12-20)

被引用文献数

21

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Indonesia is one of the world’s largest fresh pepper (Capsicum spp.) fruit-producing countries, and hot peppers are essential spices in Indonesian cuisine. During the last two decades, begomovirus, which is transmitted by the whitefly, Bemisia tabaci (Gennadius), and causes pepper yellow leaf curl disease, began to cause a huge economic loss by damaging pepper plants in Indonesia. In the present study, a highly efficient inoculation method was established for Pepper yellow leaf curl Indonesia virus (PepYLCIV), the most infectious bipartite begomovirus in pepper plants cultivated in North Sumatra, by combining agroinoculation and subsequent grafting. Partial tandem repeats of PepYLCIV DNA A and B were constructed and cloned into a binary pGreenII vector, and their infectivity was tested. Co-inoculation of Nicotiana benthamiana L. and Solanum lycopersicum L. ‘Momotaro’ with PepYLCIV DNA A and DNA B resulted in the production of typical begomoviral symptoms. Both the injection of the cotyledons with cultured agrobacteria and the inoculation of the hypocotyl with agrobacterial colonies induced viral symptoms in pepper No. 218 (C. annuum L.) seedlings in approximately 55–75%. When agroinoculated symptomatic No. 218 was grafted onto an uninfected ‘Takanotsume’ (C. annuum), all newly elongated shoots from the rootstock of ‘Takanotsume’ produced typical begomoviral symptoms. Agroinoculation combined with subsequent grafting provides a highly efficient method for introducing PepYLCIV into pepper plants.

著者

Tomoko Hirota Shinya Yoshida Takayuki Sawada Yasunori 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-121, (Released:2017-12-19)

被引用文献数

1

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The black soybean landrace ‘Tanbaguro’, consumed as vegetable seeds (edamame), is characterized by its uniquely high maltose production after heat processing, which is an important trait contributing to its enhanced sweetness. We investigated starch properties related to the maltose production in edamame together with several other affecting biochemical factors. As a result, it was estimated that the low gelatinization temperature of starch predominantly contributed to the increased maltose production and was associated with the increased proportion of short-chain amylopectin, although β-amylase activity did not show any significant correlation with maltose productivity. Additionally, amylose content may promote maltose production by the progression of starch gelatinization together with its effectiveness as a substrate of β-amylase. These starch properties were sensitive to ambient temperature, especially during the latter half of the maturation period. Therefore, it is suggested that maltose productivity in edamame seeds was strongly correlated with the maturing properties of soybean lines. On the other hand, starch content that was insensitive to ambient temperature during the maturing period was also estimated to contribute to the increase in maltose productivity complementarily by multiple regression analysis for varietal difference. These results suggested that starch content showed the additional importance in the varietal difference of maltose productivity among earlier maturing soybean lines than ‘Tanbaguro’.

著者

Tran Duy Vinh Yuichi Yoshida Mitsuo Ooyama Tanjuro Goto Ken-ichiro Yasuba Yoshiyuki Tanaka

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-114, (Released:2017-11-17)

被引用文献数

14

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

著者

Yasushi Kawasaki Tadahisa Higashide

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-118, (Released:2017-11-17)

被引用文献数

1

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Fruit growth represents the balance between material influxes via xylem and phloem and efflux by transpiration via the stomata of the calyx and cuticle of fruit, which determines the yield and soluble solids content (SSC). Knowledge of these factors is important for the production of high-SSC tomato fruit, but no physiological indicator is available to allow prediction of fruit yield and SSC for breeding and crop production purposes. To identify indicators, we grew Japanese, Dutch, Japanese × Dutch, and high-SSC cultivars and sought correlations of the fluxes to fruit with yield and SSC. To estimate the contributions of the xylem, phloem, and transpiration fluxes to fruit weight increase, we measured 2-day growth rates of intact, detached, and heat-girdled (peduncle steamed for 90 to 120 s) fruits treated at 14, 28, or 42 days after flowering (DAF). Xylem influx was much lower in the high-SSC cultivar than in the others. Phloem influx was lower in the Dutch and hybrid cultivars at 28 DAF. Transpiration efflux was greater in the Japanese cultivar at 42 DAF. Fruit growth rate at 14 DAF was positively correlated with yield, and phloem influx per fruit weight increase at 14 and 28 DAF was positively correlated with SSC. These results show how the xylem, phloem, and transpiration fluxes of fruit can predict fruit yield and SSC. This information will help the production and breeding of high-SSC fruit.

著者

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

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-117, (Released:2017-11-08)

被引用文献数

13

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‘Kurenainoyume’ is a new red-fleshed apple cultivar with a gradually increasing cultivation area. However, cork spot-like physiological disorder (CSPD) of the apple skin has become a serious problem over the years. Therefore, the development of strategies to reduce and prevent CSPD is strongly desired by farmers. To this end, we investigated the effectiveness of i) spraying calcium (Ca), boron (B), or both on the tree and ii) pre-harvest fruit bagging. Ca or B solutions or both did not decrease CSPD incidence. Furthermore, no relationship was detected between CSPD and the Ca/B content of fruit and leaves, demonstrating that the occurrence of CSPD might not be due to a deficiency in these elements. Pre-harvest fruit bagging reduced the development of CSPD depending on the light permeability of the paper bags used. Moreover, CSPD development was positively correlated with sunshine duration. Therefore, to prevent CSPD, fruit should be covered with light-impermeable paper bags at least from mid-July to late-September because the fruit covered for a shorter period developed CSPD. Thus, we propose that pre-harvest fruit bagging with light impermeable paper could be a useful and practical strategy to reduce or prevent CSPD in ‘Kurenainoyume’.

著者

Ziaurrahman Hejazi Shuji Ishimura Chitose Honsho Takuya Tetsumura

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-125, (Released:2017-11-08)

被引用文献数

10

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A practical dwarfing rootstock for the persimmon (Diospyros kaki Thunb.), ‘MKR1’, is normally propagated by cuttings collected from root suckers. However, optimal conditions for propagating leaf-bud cuttings from this variety have not been researched. Thus, several methods influencing survival, rooting and root system structure were investigated in the present study. Cuttings planted in late June survived and rooted better than those planted in late July and August, and the rooted cuttings planted in late June also survived winter better. The two different irrigation methods, either a mist system, or a tray with a polyethylene tent (tray-polyethylene-tent, or TPT) did not significantly affect survival and rooting. However, the primary root length was longer in the TPT and the root dry weight was heavier under the mist system. Although the rooting medium did not significantly affect the survival of cuttings, the rooting percentage of cuttings planted in perlite was the lowest. The cuttings planted in peat in late June and placed under the mist system had adventitious root initials 17 days after planting and adventitious roots were observed on the cuttings by 22 days after planting. A quadratic regression curve predicted that the highest rooting percentage would result from treatment of ‘MKR1’ cuttings with approximately 2000 mg·L−1 indole-3-butyric acid (IBA), while a different curve predicted that the lowest root number would result from treatment with approximately 1000 mg·L−1 IBA. Interestingly, more than 50% of the cuttings treated with a quick dip in 0 mg·L−1 IBA successfully rooted. Although the treatment with a higher IBA concentration resulted in greater root system development on the rooted cuttings, treatment with very high IBA concentrations such as 4000 or 5000 mg·L−1 caused fading of leaves and dieback of cuttings.

著者

Yoshiyuki Tanaka Shiho Fukuta Sota Koeda Tanjuro Goto Yuichi Yoshida Ken‑ichiro Yasuba

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-115, (Released:2017-10-28)

被引用文献数

15

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Capsinoids are low-pungent capsaicinoid analogues in chili pepper fruits. They exhibit various bioactivities in humans similar to capsaicinoids, but do not produce a nasty burning sensation, encouraging their application in foods and supplements. Previous reports demonstrated that loss-of-function of putative aminotransferase (pAMT) leads to low-pungency and capsinoid accumulation. Therefore, the pamt allele is a useful gene in chili pepper breeding programs to enhance health-promoting properties. Eight loss-of-function alleles have been identified in the Capsicum genus, but the variation in pamt alleles remains to be fully elucidated. In this study, we identified one novel loss-of-function allele from the analysis of low-pungent chili pepper ‘No. 4034’ (C. chinense). ‘No. 4034’ contained mainly capsinoid with an undetectable level of capsaicinoid. A genetic complementation test was conducted by crossing ‘No. 4034’ with other accessions. The results indicated that ‘No. 4034’ possessed a loss-of-function pamt allele. Sequence analysis showed that the novel mutant allele contained a 7-bp insertion (TCGGTAC) in the 16th exon region, which we designated as pamt9. The insertion caused a frameshift mutation and resulted in a truncated protein. Gene expression analysis showed that the expression level of pAMT specifically decreased among biosynthetic genes tested here in ‘No. 4034’, compared with that of pungent accession. pamt9 will be useful for low-pungency and capsinoid breeding, and will provide additional information for variations in pAMT mutants.

著者

Ryohei Nakano Hidemi Akimoto Fumio Fukuda Takashi Kawai Koichiro Ushijima Yosuke Fukamatsu Yasutaka Kubo Yuichiro Fujii Ken Hirano Kunihisa Morinaga Naoki Sakurai

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-094, (Released:2017-10-12)

被引用文献数

15

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Split-pit in peach fruit is a problematic disorder. Split-pit fruit cannot be detected based on external appearance, and contamination of fruit by split-pit reduces its reliability in the marketplace. Here, we demonstrate that split-pit fruit can be identified by a nondestructive acoustic vibration method and a unique approach based on the ratio of the third (f3) to the second (f2) resonant frequency. The response-resonant frequency spectra showed that the peaks of f2 frequencies in split-pit fruit were shifted to much lower values than those in normal fruit, whereas those of f3 frequencies showed only small shifts. The calculated f3/f2 ratios in most normal fruit were in the range of 1.35–1.4, whereas those in split-pit fruit were 1.45–2.0. Analysis of more than 300 fruit samples revealed that by setting the f3/f2 cut-off value at >1.45, 95% of split-pit fruit in the fruit samples were detected, whereas only 1.5% of normal fruit were missorted as split-pit fruit. A model for simulating the vibration properties of peach fruit was developed by using the finite element method. The simulated vibration patterns showed that f3/f2 values were increased by the insertion of split pit, indicating that, at least partially, the observed high f3/f2 values in split-pit fruit directly reflected split-pit occurrence. These results clearly demonstrate that the use of f3/f2 ratios obtained using an acoustic vibration method can effectively detect fruit with split-pit. The possibility of installing acoustic vibration devices in peach sorting lines and the application of portable devices to unpicked fruit on the tree are discussed.

著者

Hiroki Ueno Takeshi Maeda Naoki Katsuyama Yu Katou Satoshi Matsuo Kanako Yano Akira Ando Kaori Nagasuga Mizuki Yamada Shunsuke Imanishi

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-101, (Released:2017-10-11)

被引用文献数

11

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Several Japanese tomato cultivars develop a physiological disorder called leaf marginal necrosis, which occurs in relatively young compound leaves. Although the positions of the observed symptoms differ from those caused by inadequate potassium (K+) supplementation, previous studies have reported a relationship between the reduction of K+ content and the occurrence of this disorder. However, the mechanism of the relationship between K+ deficiency and leaf marginal necrosis remains unstudied. In the present study, the relationship between K+ deficiency in leaflets and leaf marginal necrosis was investigated by cation measurement and gene expression analysis to understand the possible mechanism responsible for the induction of leaf marginal necrosis. First, cation measurement of the two cultivars differing in their symptom intensities showed a trend of K+ reduction in the ‘CF Momotaro J’ cultivar developing leaf marginal necrosis at the tip leaflets positioned under the flowering fruit truss. Next, a comparison between the basal and tip region of the leaflet from four cultivars differing in their symptom intensities revealed that the K+ concentration in tip leaflets was significantly lower in the tip regions compared to the basal region, especially in the two cultivars ‘CF Momotaro J’ and ‘Momotaro grande’, leading to leaf marginal necrosis. The gene expression analysis of the basal and tip regions identified that the expression patterns of jasmonate-related genes were upregulated in the tomato leaflets with low K+ concentration. The gene expression of a leaf senescence marker gene, a homologue of the SAG12 gene of Arabidopsis thaliana, was detected only in the leaf tip region samples with the lowest K+ concentration. Furthermore, ‘CF Momotaro J’ plants cultivated with K+-supplemented medium showed an increase in the K+ concentration, a decrease in the occurrence of leaf marginal necrosis, and down-regulation of the expression of jasmonate-related genes in tip leaflets. These results indicate that tomato leaf marginal necrosis occurs because of K+ starvation in the tip region of leaflets, leading to the activation of jasmonate-induced signal for necrosis.