著者

Yutaka Sawamura Yuko Suesada Toshihiko Sugiura Hideaki Yaegaki

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-052, (Released:2017-01-20)

被引用文献数

15

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A major goal of peach breeding programs in Japan is to develop cultivars with lower chilling requirements than the leading cultivars. Low-chill cultivars can be grown in subtropical as well as temperate regions. We investigated the chilling requirements (chill units; CU), heat requirements (growing degree hours; GDH), and blooming dates of 7 leading Japanese peach cultivars, 3 subtropical low-chill cultivars, and a promising new selection, Momo Tsukuba 127. In general, the CU of the 7 leading cultivars were higher than those of the 3 subtropical cultivars and Momo Tsukuba 127. The chilling and heat requirements were determined for the 3 leading high-chill cultivars (‘Akatsuki’, ‘Hikawahakuhou’, and ‘Kawanakajimahakutou’), the low-chill cultivar ‘Okinawa 1’, and Momo Tsukuba 127 during 4 seasons at a single location. The CU for ‘Okinawa 1’ and Momo Tsukuba 127 were significantly lower than those of the three high-chill cultivars. Because Momo Tsukuba 127 had lower chilling requirements than the 7 leading peach cultivars but higher chilling requirements than the subtropical cultivars, we classified this new selection as a mid-chill variety. We used the CU and GDH, along with local temperature data, to estimate the blooming dates of 4 cultivars and the new selection during 11 seasons at one location. Regression analyses showed high correlations between the calculated and actual blooming dates. We also compared calculated and actual blooming dates for the 3 leading cultivars and Momo Tsukuba 127 at between17 and 21 locations per genotype. A total of 25 locations were used, and these were widely spread over the temperate zones of Japan. The correlations between the calculated and actual blooming dates were close to 1:1. Our results indicated that our CU and GDH values, along with actual temperature data, could be used to reliably estimate the blooming dates of the genotypes. Because of its lower chilling requirements, the new selection, Momo Tsukuba 127, bloomed 7 or more days earlier than the leading peach cultivars in this study.

著者

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

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-028, (Released:2017-01-14)

被引用文献数

36

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The responses of three kiwifruit cultivars, Actinidia chinensis ‘Sanuki Gold’, A. chinensis ‘Rainbow Red’, and A. deliciosa ‘Hayward’ to various storage temperatures (0, 5, 10, 15 and 20°C) for 8 weeks were investigated. The rate of fruit which initiated ethylene production due to rot development increased with increases in storage temperature. Early-maturing cultivars, ‘Rainbow Red’ and ‘Sanuki Gold’ fruit stored at 5, 10, and 15°C showed drastic softening and a decrease in titratable acidity (TA) to an edible level within 4 weeks without detectable ethylene production, whereas fruit stored at 0 and 20°C maintained high firmness and TA even after 8 weeks unless they were infected with rot. A late-maturing cultivar, ‘Hayward’ fruit stored at 5 and 10°C softened more rapidly than when stored at 0, 15, or 20°C. Treatment with 1-Methylcyclopropene (1-MCP) did not suppress the low temperature modulated fruit ripening in any cultivars, indicating its independence from ethylene. These results suggest that ‘Sanuki Gold’ and ‘Rainbow Red’ are more sensitive to low temperatures compared to ‘Hayward’ and the sensitivity is involved in the determination of storage life and how early the fruit matures on the vine.

著者

Takuya Wada Yuji Noguchi Sachiko Isobe Miyuki Kunihisa Takayuki Sueyoshi Katsumi Shimomura

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.MI-142, (Released:2017-01-14)

被引用文献数

11

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A strawberry core collection was established based on simple sequence repeat and cleavage amplified polymorphic sequence marker polymorphisms in 119 strawberry cultivars using the “PowerCore” program. The core collection consisted of 19 cultivars. The correlation coefficients for the diversity index were significant between the core collection cultivars and all cultivars. Allele frequencies of each marker allele were not significantly different between the core collection cultivars and all cultivars according to Fisher’s exact test. Cluster analysis indicated that the selected core collection cultivars evenly distributed throughout the multiple clusters and principle component analysis clearly showed major principle components of core collection cultivars distributed widely among those of all cultivars. Furthermore, core collection cultivars tended to harbor minor alleles. These results demonstrated that the core collection cultivars were suitably selected in terms of reflecting the genetic diversity of all strawberry cultivars.

著者

Kanjana Worarad Xiaonan Xie Inna Martha Rumainum Chairat Burana Kenji Yamane

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-043, (Released:2016-12-29)

被引用文献数

5

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Fluridone, an inhibitor of carotenoid biosynthesis, is known to prevent abscisic acid (ABA) biosynthesis and to affect the germination and dormancy of seeds in several plant species. This study investigated the effects of fluridone on seed germination of the ornamental peach ‘Yaguchi’, and on the transcript levels of genes related to seed dormancy in this plant. Seeds were rinsed for 2 days under running tap water (RS), then soaked for 1 day in 100 μM fluridone (F), and kept at 5°C for 2 weeks (2W). The germination rate significantly increased from 0% to 9.5% in the RS+F treatment and to 71.4% in the RS+F+2W treatment, while no germination occurred in the RS and RS+2W treatments. Seedlings in RS+F and RS+F+2W treatments formed dwarf shoots, i.e. about 10 cm, and morphological lesions on the leaves. The ABA content in embryonic axes decreased after RS and increased with RS+2W. It was decreased by the RS+F+2W treatment. RS+F+2W downregulated ABA-hy3, which encodes enzymes with key roles in ABA catabolism, while its effects on 9-cis-epoxycarotenoid dioxygenase (NCED1) in relation to ABA synthesis fluctuated. In contrast, Empfindlicherim Dunkelroten Licht 1 (EID1) was upregulated after fluridone treatment, suggesting that fluridone may activate positive ABA signaling pathways. Expression of GA2-oxidase8 (GA2-ox8) was not affected by fluridone. MADS-box protein JOINTLESS (LeMADS) and Late embryogenesis abundant protein D-34 (LEA D-34) were downregulated in the RS+F+2W treatment, suggesting that the expression of these genes are controlled by low temperature and the ABA inhibitor, and are involved in seed dormancy. These results suggest that ABA inhibitor treatments can be an alternative method to promote germination by controlling ABA content and its metabolism, and consequently changing expression of certain ABA- and dormancy-related genes including ABA-hy3, EID1, LeMADS, and LEA D-34, even under insufficient chilling conditions.

著者

Keiko Kataoka Kazuya Sugimoto Hiroaki Ohashi Hisashi Yamada

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-041, (Released:2016-12-03)

被引用文献数

9

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Tomato plants were grown with a drip irrigation system to evaluate the effects of a novel organo-mineral fertilizer [2:10:1 (w/w/w) mixture of calcium sulphate, ground rice bran, and humic acid] (OMF), which can mitigate salinity stress, on plant growth, fruit yield, and the incidence of blossom-end rot (BER) under salinity stress. Salinity stress was applied by drip irrigation with 50 mM of NaCl. Plant growth with OMF was lower than that with chemical fertilizer (CF). Higher levels of K and P were obtained in the leaves from plants grown with OMF. OMF inhibited Na accumulation and proline increase in the leaves and was considered to alleviate salinity stress. Salinity treatment caused a decrease in fruit weight and an increase in ascorbic acid, sucrose, glucose, fructose, and glutamic acid. Tomato plants grown with OMF had smaller fruit than with CF without salinity, but the incidence of BER under salinity was reduced by OMF. The water soluble Ca content of the distal half of young tomato fruit was significantly decreased with salinity treatment. The incidence of BER under salinity was significantly lower in OMF than in CF, but there was no difference in the concentration of every form of Ca between CF-salinity and OMF-salinity treatments. The reduction in BER incidence with OMF treatment could not be explained by the differences in Ca concentration. The mechanism of the reduction in BER with OMF was not clear, so further studies are necessary.

著者

Jatuporn Anuchai Ching-Hsiang Hsieh

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.MI-151, (Released:2016-12-01)

被引用文献数

10

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Changes in light quality strongly affect several plant anatomical, physiological, morphological, and biochemical parameters of orchid tissue culture seedling growth. In this experiment, ways in which light quality influence plant photosynthesis, growth parameters, and carbon dioxide rhythms of different sizes (stage I, II, and III) of Phalaenopsis tissue culture seedlings were examined. Stage I (Seedlings of 1–2 cm in height with 1–2 leaves and 1–2 roots) tissue culture seedlings were grown under six different light qualities under a T5 fluorescent lamp: White, Red (610 nm), Red (658 nm), Blue (440 nm), Red (610 nm) + Blue (440 nm), and Red (658 nm) + Blue (440 nm). After 5 months, cultured seedlings exposed to the Blue (440 nm) treatment showed significantly higher responses in terms of leaf quantities and chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid content. On the other hand, seedlings subjected to the Red (658 nm) treatment grew more stems and presented with higher fresh weight and leaf lengths compared to the results of other treatments. The number of roots increased under the Red (658 nm), Blue (440 nm) + Red (610 nm), and Blue (440 nm) + Red (658 nm) treatments. Moreover, seedlings subjected to Red light (658 nm) showed significantly higher levels of Rubisco enzyme activity than those subjected to the other treatments. Phosphoenolpyruvate carboxylase activities recorded during the nighttime in seedlings subjected to Red light (658 nm) were also significantly greater. The results showed that during stage I, the concentration of carbon dioxide rhythm ranged from 1500–1800 ppm and reflected a C3 photosynthesis system. As the seedlings matured, the carbon dioxide rhythm decreased to 400–800 ppm at night and reached stage III (CAM plant). After 5 months of culturing, the carbon dioxide rhythm of the Red (658 nm) treatment seedlings changed from C3 to CAM, while seedlings subjected to the other treatments were still in the intermediate stage (stage II). From these results, we conclude that to enhance seedling growth through commercial production, Red (658 nm) should be applied.

著者

Nao Ota Tomoyuki Nabeshima Masahiro Osakabe Shinichi Aoki Tatsuya Awano Munetaka Hosokawa

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-021, (Released:2016-11-22)

被引用文献数

5

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Although ultraviolet-B (UV-B) light (280–315 nm) irradiation effectively controls spider mites in horticultural crop production, it also causes plant damage, leading to growth suppression, changes in morphology, and leaf scorching. However, sensitivity to UV-B varies among plant species. Here, we assessed the effect of UV-B on growing perilla (Perilla frutescens var. crispa) plants. Three experiments were conducted. In the first experiment, plants of the variety ‘Akachirimenshiso’ were grown in a plastic house with natural light conditions and subjected to three treatments: natural UV (control), −UV, and natural UV plus artificial UV-B treatment (50 mW·m−2) from 0:00 to 3:00. The length of leaf blades that received additional UV-B treatment was reduced by 16.5% and 32.3% in two trials compared with that of the respective controls. In this experiment, additional UV-B irradiation turned the leaf color greener. During UV-B treatment, the values of leaf a*, an indicator of leaf redness, were significantly lower than their respective controls in both trials: 21.5 vs. 31.6 in trial I and 20.2 vs. 30.7 in trial II. For most of the parameters measured in this experiment, no differences were observed between the control and −UV treatment groups. In the second experiment, plants were irradiated with UV-B for 3 weeks at nighttime (0:00–3:00) or daytime (12:00–15:00). In the cultivar ‘Houkouakashiso’, the length of leaf blades significantly decreased by 15.9% and 20.6% under nighttime UV-B irradiation at 80 and 120 mW·m−2, respectively, compared with that of the non-irradiated controls. Irradiation at 80 mW·m−2 also decreased the width of the leaf blades by 13.1% and that at 120 mW·m−2 further decreased it by 25.0%. These results showed that UV-B irradiation at night decreased the size of perilla leaves. In addition, the value of a* became lower under UV-B irradiation in the nighttime. Thus, UV-B irradiation appeared to turn purple perilla leaves green. When plants were irradiated with UV-B in the daytime, there was no significant difference between irradiated and non-irradiated plants in the length or width of leaf blades, a*, or fresh weight of aerial parts and number of nodes on the main stem. In the third experiment, visible rays (VIS) emitted by fluorescent lamps were applied at 0:00–3:00 and 6:00–22:00. Plants were irradiated with 120 mW·m−2 of UV-B at 0:00–3:00. UV-B + VIS treatment of ‘Akachirimenshiso’ with VIS from fluorescent lamps did not significantly affect the parameters measured in this experiment compared to −UV treatment. The results of this study suggest that UV-B damage to perilla leaves can be avoided by combined irradiation with visible light.

著者

Sho Yamamoto Tetsuri Kikuchi Yutaka Yamagiwa Takashi Handa

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-006, (Released:2016-11-03)

被引用文献数

5

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Lilium auratum var. auratum Lindl. is distributed in the eastern part of Honshu, the main island of Japan. L. auratum var. platyphyllum Baker is endemic to the Izu archipelago, which consists of nine large islands located in south of Honshu’s Izu peninsula. Both varieties have been used as important parents of Oriental hybrid lily cultivars. They have large white flowers with yellow central stripes and colored spots on their tepals. L. auratum var. platyphyllum has larger flowers and wider leaves than L. auratum var. auratum. L. auratum var. platyphyllum has yellow spots, whereas L. auratum var. auratum has red or brown ones. Natural hybridization between these two taxa has been suggested on the basis of spot colors of populations in the Izu archipelago and the Izu peninsula. However, their genetic diversity and hybridity in nature have not been reported. We performed morphological analysis using 72 individuals of L. auratum var. auratum from seven populations and 72 individuals of L. auratum var. platyphyllum from six populations. We also performed simple sequence repeat (SSR) analysis using 102 individuals of L. auratum var. auratum from seven populations and 134 individuals of L. auratum var. platyphyllum from six populations. Both analyses revealed that L. auratum var. auratum and L. auratum var. platyphyllum are genetically different and that L. auratum var. platyphyllum has genetic diversity among populations in the archipelago.

著者

Machiko Fukuda Yosuke Yanai Yuka Nakano Hidekazu Sasaki Atsuko Uragami Kunihiko Okada

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-036, (Released:2016-10-29)

被引用文献数

6

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Lettuce (Lactuca sativa L.) bolting is often limiting in agricultural production as stem elongation followed by flower bud differentiation results in unmarketable plants. Thus, to solve this problem, it is important to elucidate the molecular mechanisms controlling flowering. To investigate the relationship between gene expression and flowering in lettuce, homologs of flowering-related genes were isolated and their expression over time was analyzed in three cultivars and in one breeding line by using quantitative real-time PCR. In plants grown in the field, the expression of the lettuce homologues APETALA 1 (LsAP1L) and LEAFY (LsLFYL) in the shoot apex correlated with flower bud formation, and FLOWERING LOCUS T (LsFT) expression increased during the transition from vegetative to reproductive growth. The transcription of FLOWERING LOCUS D (LsFLDL), FVE (LsFVEL), and LUMINIDEPENDENS (LsLDL) also increased with flowering. Our previous study showed that LsFT was upregulated during lettuce flowering induced under controlled high temperature conditions. Results from both studies suggest that LsFT is involved in lettuce flowering, both in natural and controlled conditions. This is also the first report on the expression of other flowering-related genes along with flowering of lettuce grown in the field.

著者

Toshio Shibuya Kenji Kano Ryosuke Endo Yoshiaki Kitaya

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.MI-154, (Released:2016-10-27)

被引用文献数

12

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Hardening with a high vapor-pressure-deficit (VPD) can decrease conductance (gs) and thereby enhance drought tolerance by reducing transpiration, which is particularly useful during transplant establishment. However, high-VPD hardening may decrease photosynthetic performance due to stomatal (diffusion) and non-stomatal (mesophyll) limitation. If gs can be lowered without significantly reducing photosynthesis, water-use efficiency (WUE = CO2 assimilation/transpiration), which is an important criterion for transplant quality, would improve. We investigated the photosynthetic properties of cucumber (Cucumis sativus L.) leaves acclimatized to different VPD levels (0.4 and 3.2 kPa at 28°C), and determined whether photosynthesis was limited by stomatal or non-stomatal factors at high VPD. The net photosynthetic rate (Pn) and gs were measured at a VPD of 0.8 kPa and a leaf temperature of 28°C under saturating light. The photosynthetic response to the intercellular CO2 concentration (Ci) was used to quantify the effects of VPD acclimatization on carboxylation efficiency. Pn did not differ significantly between acclimatization VPDs, but gs was much lower (×0.36) in high-VPD leaves at an ambient CO2 concentration of 400 μmol·mol−1. Thus, the intrinsic WUE (= Pn/gs) of the high-VPD leaves was much higher (×2.85). The Ci of high-VPD seedlings was lower than that of low-VPD seedlings, but, this did not cause any significant reduction in Pn in the high-VPD treatments because the decrease in Ci occurred within a range in which photosynthesis was not limited by ribulose-1,5-bisphosphate carboxylation in this experiment. The Pn–Ci curve did not differ between the VPD treatments, indicating that carboxylation efficiency was not affected. When VPD-acclimatized seedlings experienced a limited water supply, the low-VPD leaves showed lower leaf water potential and more severe wilting than the high-VPD leaves 30 min after water limitation began. The gs of the high-VPD leaves was significantly lower (approximately ×0.5 in average) than that of the low-VPD leaves throughout the water-supply-limitation treatment. The lower gs maintained the water status of the high-VPD leaves at less-wilting levels by decreasing transpiration. These results indicate that high-VPD hardening could enhance the tolerance to short-term drought without stomatal or non-stomatal limitation of photosynthesis when controlling gs effectively.

著者

Chikako Honda Hiroshi Iwanami Katsuki Naramoto Tsutomu Maejima Kyohei Kanamaru Yuki Moriya-Tanaka Toshio Hanada Masato Wada

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-010, (Released:2016-10-18)

被引用文献数

14

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In common apple cultivars with white flesh and red skin, it is known that fruit overload lowers fruit quality, and that skin anthocyanin concentrations are reduced by bagging treatment and warmer climatic conditions. In this study, the effects of these factors on anthocyanin accumulation in the flesh of red-fleshed apples were investigated using ‘Geneva’ and ‘Pink Pearl’ apple cultivars. Excess fruiting resulted in decreased anthocyanin concentration in the flesh and the titration acidity of the fruit in both cultivars. Fruit bagging treatments using double-layer paper bags revealed that anthocyanin was synthesized to a certain extent in the flesh under dark conditions in both cultivars. The treatment significantly reduced anthocyanin accumulation in the flesh of bagged ‘Geneva’ apples compared with unbagged fruit, but no inhibitory effect was clear in ‘Pink Pearl’ apples. In both cultivars, the anthocyanin concentration in the flesh of unbagged apples grown in sunlight was higher than that in unbagged apples grown in shade, whereas there was no difference between positions for bagged fruit. In apples grown in either sunlight or shade, no significant difference was found between anthocyanin concentrations in the sun-exposed side and shaded side of fruits. These results indicate that sunlight irradiation partially promoted anthocyanin accumulation in the flesh of unbagged ‘Geneva’ and ‘Pink Pearl’ apples and accelerated its accumulation on both the sun-exposed and the shaded side. A comparison of the fruit quality of ‘Pink Pearl’ apples grown in different climatic regions showed that apples harvested at Suzaka, a warmer region, were lower in firmness, starch index, and titration acidity and higher in soluble solids concentration compared with those from Morioka, a cooler region. The anthocyanin concentration in the flesh of ‘Pink Pearl’ apples from the trees grown at Morioka was more than ten-fold higher than that in apples from the trees grown at Suzaka. Our results suggest that an appropriate fruit load, growth in sunlight, and growth under cooler climatic conditions, may redden the flesh of red-fleshed apples, as is the case for common apples.

著者

Keiko Sato Yoshinori Ikoma

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-003, (Released:2016-10-08)

被引用文献数

7

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To improve labor-saving during harvests, the efficiency of handpicking fruit was examined for the satsuma mandarin with the plant growth regulators gibberellin (GA), prohydrojasmon (PDJ), and ethephon (ET). In this study, concentrations of plant growth regulators were set 5 mg·L−1 for GA and 50 mg·L−1 for PDJ, respectively. Spraying of a GA plus PDJ solution on Aug. 27, Sep. 21, and Oct. 27 (triplicate spraying) improved the success rate of handpicking (SRH), as compared with a control. Furthermore, ET treatment in addition to triplicate spraying of GA plus PDJ increased SRH. A one-time treatment of GA plus PDJ also showed a significant effect on handpicking efficiency when applied in mid to late September. It was clear that the effect of GA plus PDJ on SRH was improved when 400 mg·L−1 ET was used instead of 200 mg·L−1, but this ET concentration (400 mg·L−1) caused massive leaf abscission (data not available). Spraying with 300 mg·L−1 ET alone showed 37.1% leaf abscission: therefore, we assumed that a GA plus PDJ treatment with a combination of less than 300 mg·L−1 ET would increase peel firmness without serious leaf abscission and a negative effect on SRH. In addition, the soluble solids and the acidity in the combination spraying of GA plus PDJ in late September with 300 mg·L−1 ET and less were almost the same as the control. Thus, our results indicated that the treatment of 5 mg·L−1 GA plus 50 mg·L−1 PDJ in late September combined with ET (200 mg·L−1 < ET < 300 mg·L−1) from late October to early November was suitable for increasing SRH without impairing fruit quality and causing serious leaf abscission.

著者

Yoshikuni Kitamura Tatsuya Uemachi Yukari Kato

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.MI-160, (Released:2016-09-15)

被引用文献数

2

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We compared transpirations and vase lives of cut hydrangea (Hydrangea spp.) flowers using two cultivars with lacecap inflorescence (‘Blue sky’ and ‘S-1’) and their mutants with hortensia inflorescence (‘BM-1’ and ‘SM-1’). There was no significant difference in the transpirations from cut flowers with the lacecap and hortensia inflorescences in the two cultivars. However, transpiration from ‘S-1’ cut flowers tended to exhibit higher transpiration than ‘SM-1’. There was also no significant difference in the vase lives of ‘Blue sky’ and ‘BM-1’. However, ‘S-1’ had a significantly shorter vase life (3 days) than its mutant ‘SM-1’. This was due to the greater number of total florets in ‘S-1’ cut flowers than ‘SM-1’. The non-decorative floret clusters and clusters of petals, stamens, and pistil of decorative florets exhibited lower temperatures than decorative sepals in both ‘Blue sky’ and ‘BM-1’ on thermal images. Therefore, we estimated the transpiration from the non-decorative florets and studied the effect of removal of non-decorative florets on the vase life of cut flowers using two lacecap cultivars, ‘Blue sky’ and ‘Fairy eye’. Estimated transpirations from the non-decorative florets of ‘Blue sky’ and ‘Fairy eye’ accounted for approximately 61.8% and 39.7%, respectively, of total transpirations per cut flower, and the removal of non-decorative florets significantly extended the vase lives of cut flowers (18 and 22 days, respectively). The difference in the contribution of the non-decorative florets to the transpiration between the cultivars is due to the difference in the number of non-decorative florets in the inflorescences. We conclude that the use of cut flowers that do not bear too many non-decorative florets and/or treatments that suppress the transpiration from non-decorative florets would be effective in extending the vase life of cut hydrangea flowers with lacecap inflorescence.

著者

Geng Zhang Masahumi Johkan Masaaki Hohjo Satoru Tsukagoshi Toru Maruo

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-008, (Released:2016-09-08)

被引用文献数

28

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Chronic kidney disease has become a major public health problem worldwide. The aim of this study was to investigate the differences in plant growth and photosynthesis among three lettuce (Lactuca sativa) types with different morphological characteristics under low potassium conditions, providing information for improving the method of low-potassium lettuce culture. Lettuce was hydroponically grown in half-strength Enshi formula nutrient solution containing 4, 2, or 1 me·L−1 K+. The plant yield and relative growth rates (RGR) of all three lettuce types were lowest under a treatment with 1 me·L−1 K+. In green leaf lettuce, reductions in both the net assimilate rate (NAR) and leaf area ratio (LAR) led to a decline in RGR. In Boston lettuce and romaine lettuce, the reduction of RGR was mainly due to a reduction in LAR, and to a lesser extent caused by NAR. Reduced potassium in the nutrient solution had a greater effect on mature leaves than on newly expanded leaves for all three lettuce types. In green leaf lettuce and Boston lettuce, photosynthetic rates of mature leaves significantly decreased under reduced potassium treatments, with a steady or gradually increased intercellular CO2 concentration; this indicated that non-stomatal factors suppressed photosynthesis. In romaine lettuce, the photosynthetic rate was less influenced by reduced potassium levels in the nutrient solution, and the significant increase observed in leaf mass per area might contribute to maintaining photosynthesis in the leaf. The decrease in photosynthesis in mature leaves exhibited a similar trend to the decreased potassium content in the leaves within the three lettuce types, but the factor related to the reduction of photosynthesis was different.

著者

Fumio Fukuda Yuki Tomita Yukihito Aishima Kumiko Koumoto Yuichiro Fujii Ken Hirano Kunihisa Morinaga Naohiro Kubota

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-012, (Released:2016-08-18)

被引用文献数

3

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Reddish pulp is one of the most serious disorders in peach production, in which originally white flesh undergoes pink to red discoloration with the development of a mealy texture. In order to clarify the relationship between the incidence of reddish pulp and flowering date, the occurrence of reddish pulp was investigated in ‘Benishimizu’ and ‘Shimizu Hakuto’ fruit with different flowering dates for three seasons. In both cultivars, the percentage of fruit with reddish pulp was higher in early flowering fruit than late flowering fruit in all three seasons. Analysis of pectin and boron contents in immature fruit sampled from June 23 to July 8, prior to observing the symptoms of reddish pulp, showed no statistically significant differences in pectin content between early and late flowering fruit. On the other hand, the boron content in flesh was significantly lower in early flowering fruit that bloomed on April 1 than in late flowering fruit that bloomed on April 11 in ‘Benishimizu’. In addition, a significantly higher total polyphenol content, which is one of the characteristics of reddish pulp, was found in early flowering fruit. The results indicate that the flowering date has a large impact on the incidence of reddish pulp, and the disorder is more prevalent in early than late flowering fruit. The possible relationships among the development of reddish pulp, boron deficiency, pectin content, and increase in total polyphenol content are discussed.

著者

Takayuki Mizuno Naoko Fukuta Hiroko Shimizu-Yumoto

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-001, (Released:2016-08-03)

被引用文献数

8

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Double-flowered Eustoma, a popular cut flower, sometimes shows nonuniform coloration of its petals when harvested at the flower bud stage. At the tips of the petals, pale greenish areas remain after the flowers open. This considerably reduces the value of cut Eustoma. In this study, to identify appropriate postharvest treatments leading to normal coloration of these cut flower buds, we investigated the influence of harvest stage, temperature, sugar, and methyl jasmonate (MeJA) on petal coloration using the Eustoma ‘Voyage (Type II) Blue’. Investigation of the harvest stage, which was compared at three flower bud stages (STG2, 3, and 4), revealed that detached pale greenish flower buds (STG2 and 3) had a high probability of becoming nonuniformly colored flowers, so these stages were used for subsequent investigations. Temperature, which was investigated at 20, 25, 30, and 35°C, did not show any influence on petal coloring. Investigation of sugar treatments, such as 1% or 3% glucose or sucrose, also showed no influence. However, MeJA treatment led to a significant difference in petal coloration. The nonuniform coloration of petals was reduced by continuous exposure to MeJA vapor. Furthermore, we performed shorter MeJA treatments, such as for 1 or 2 days after harvesting, which reduced the nonuniform coloration as well as continuous MeJA exposure. To evaluate the effect of MeJA treatment on petal coloration, we measured the rate of pale green areas of petals using digital images. The analysis revealed that the greenish areas in petals exposed to MeJA vapor were significantly smaller than in petals not exposed to MeJA. In addition, there were fewer days to flowering after MeJA treatment. We concluded that postharvest treatment with MeJA is effective for reducing nonuniform coloration of early harvested flower buds of the double-flowered Eustoma ‘Voyage (Type II) Blue’.

著者

Kenichi Tomi Eri Sakaguchi Saki Ueda Yasuki Matsumura Takahiro Hayashi

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.MI-098, (Released:2016-05-26)

被引用文献数

9

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Physiological and psychological effects of rose aromas have been reported. Many of these reports focused on the effect of rose essential oils, but the effect of rose fresh flowers on humans has not been sufficiently reported. We were also interested in the possibility of using rose hydrosol, a byproduct of the rose essential oil manufacturing process, for aromatherapy. In this study, the physiological and psychological effects of rose ‘Wishing’ fresh flowers and their hydrosols on humans were evaluated. R–R power spectral analysis of heart beats revealed the sedative effect of the fresh flowers’ scent. On the other hand, hydrosols did not show such an effect. Gas chromatography (GC) and GC-mass spectrometry (GC-MS) analysis indicated the possibility that the sedative effect of the fresh flowers’ scent was derived from β-caryophyllene, phenylethyl acetate, and 3,5-dimethoxy toluene. It is possible that fresh rose flowers may be an alternative to rose essential oils in aromatherapy.

著者

Shigeto Morita So Sugiyama Akira Tateishi Shigeru Satoh

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.MI-127, (Released:2016-05-19)

被引用文献数

7

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Transport of water into cells is mediated by plasma membrane intrinsic protein (PIP) families of aquaporin, which are involved in petal cell expansion during flower opening. In this study, we performed comprehensive characterization of aquaporin family genes and analyzed the expression of PIP genes in petals of opening flowers to examine the role of PIPs in flower opening in the carnation (Dianthus caryophyllus L.). A database search of the genome sequence revealed the existence of 26 aquaporin genes with 8 members of the PIP subfamily in the carnation ‘Francesco’. The expression of all the PIP genes was validated by the existence of expressed sequence tags, and expression analysis by quantitative reverse transcription-PCR showed that DcPIP2;1 and DcPIP1;1 are the two major PIP isoforms expressed in petals of the ‘Pure Red’ carnation. The transcripts of these two genes were also detected abundantly in other floral tissues including the calyx, style, receptacle, and ovary, as well as stems and leaves. The expression of DcPIP2;1 and DcPIP1;1 in petals was maintained at a high level throughout the flower opening process. These data suggest a putative role of these PIPs in petal growth for flower opening.

著者

Claudio Kendi Morikawa

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.MI-136, (Released:2016-05-17)

被引用文献数

12

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Contamination of vegetables with cadmium (Cd) is a worldwide problem. Three pot experiments were carried out to reduce the Cd content in fresh fruit of 52 Japanese pepper (Capsicum annuum L.) cultivars. The first experiment was carried out to select low Cd pepper cultivars after growing on a 2.1 Cd mg·kg−1 contaminated soil. The second experiment was carried out to select low Cd-accumulating pepper rootstocks while the third experiment was carried out to evaluate grafting as a tool to reduce Cd in fresh peppers. The ability of pepper cultivars to accumulate Cd in fresh fruit was significantly different. The Cd content ranged from 0.018 to 0.088 mg·kg−1 of fresh weight (FW). Among the pepper rootstocks cultivated in Japan, the cultivar ‘Daisuke’ was selected as a low-Cd accumulating rootstock. The grafting of cultivar ‘Ace’ onto ‘Daisuke’ rootstock reduced the Cd content by 40% in fresh peppers. However, other trace elements such as Fe, Mn and Zn, which are important for human nutrition, were also reduced by 20%, 29%, and 42%, respectively.

著者

Ichiro Honda Hiroshi Matsunaga Kaori Kikuchi Satoshi Matuo Machiko Fukuda 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.MI-120, (Released:2016-04-26)

被引用文献数

12

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The roles of plant hormones in the early growth of pepper fruit (Capsicum annuum L.) were investigated. An exogenous hormone treatment study indicated that cytokinin (CK) was more effective at stimulating early fruit growth in two lines than auxin or gibberellin (GA). Endogenous levels of CKs, 3-indole-acetic acid (IAA), and GAs in young pollinated and unpollinated fruit of four lines (two with medium-sized and two with small fruit) were also investigated. In pollinated fruit, the level of trans-zeatin riboside (tZR) increased with fruit size. In unpollinated fruit, tZR did not increase in any lines. IAA levels decreased gradually after flowering and did not differ between pollinated and unpollinated fruit in any lines. Levels of GA1 in unpollinated fruit of the lines in which unpollinated fruit were relatively well enlarged were slightly higher. In the line in which unpollinated fruit could not enlarge, GA1 levels of all samples were lower than the others. These results indicate that tZR is important in the early enlargement of pollinated pepper fruit, and that GA1 is involved in early fruit enlargement, especially in unpollinated pepper.