著者

岡本 五郎 山本 恭子 島村 和夫

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.53, no.3, pp.251-258, 1984 (Released:2007-07-05)

参考文献数

16

被引用文献数

5 4

---

4倍体ブドウの巨峰系品種の中で, ‘巨峰’及び‘ピオーネ’の果房には多くの無核小粒果が混入するが, これに比べて‘紅瑞宝’, ‘紅伊豆’, ‘レッド•クイーン’, ‘ハニー•レッド’ではより多くの有核果が着粒し, 無核果の混入は少ない. このような無核果の着生原因を知るために, 各品種の花器の完全性と胚珠への花粉管の伸長を比較した.‘巨峰’及び‘ピオーネ’では, 胚珠の形態的異常や胚のうの未発達が他の品種より多くみられた. 生殖核と栄養核のない花粉も両品種で特に多かったが, 寒天培地上での発芽能力とは一定の関係がなかった. 子房内に伸長した花粉管の数は, いずれの品種でも子房組織の中央部または下部で著しく減少したが, ‘巨峰’と‘ピオーネ’ではその減少が特に著しく, 胚珠へ到達する花粉管も極めて少なかった.これらのことから, ‘巨峰’及び‘ピオーネ’で有核果の着生が少ないのは, 胚珠の発達が十分でないこと, 及び花粉管の子房内組織での生長が不活発であるために胚珠が不受精になりやすいことが原因であると考えられる. これらの品種では, 不受精に終った子房の多くがそのまま生長を続けて無核果になるものと思われるが, その機構は不明である.

著者

Tomohiro Kondo Hana Morizono

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-006, (Released:2022-08-20)

被引用文献数

3

---

To determine the effects of drought stress, especially light drought stress, on flower number in passion fruit, one-year-old passion fruit plants grown in 7.5 L plastic pots were subjected to different soil water content treatments, namely wetness, light drought, and heavy drought for two months. Average, maximum, and minimum soil water contents (v/v) were 44, 47, and 41% in the wetness treatment, 23, 40, and 11% in the light drought treatment and 11, 33, and 6% in the heavy drought treatment. Flower number decreased as the strength of drought stress increased, although the number of nodes and flower buds did not. Flowering periods were from June 27 to July 19 in the wetness treatment and June 26 to July 16 in the light drought treatment with three peaks around July 1, 6, and 13. In the heavy drought treatment, the flowering period was from July 11 to 18 with one peak. The flower bud number was not affected by drought stress. Light drought stress did not suppress vegetative growth, such as vine length, leaf number, leaf length, or photosynthetic rate, although heavy drought stress did. Stomatal conductance was suppressed by light drought only at 12:00PM and by heavy drought throughout the day. Leaf water potential was decreased by heavy drought at 3:00PM, but not by light drought. In the wetness and light drought treatments, visible wilting was not observed, and in the heavy drought treatment the plants wilted before irrigation, although they recovered about 15 min after irrigation. In conclusion, even light drought stress, which did not suppress vegetative growth, reduced the flower number in passion fruit. Drought stress suppressed flower bud development but not differentiation.

著者

Hardeep Singh Masood Khezri John Bushoven Sharon Benes Faranak Hadavi Gurreet Brar

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-379, (Released:2022-08-09)

---

Citrus nursery trees in California must be grown in insect exclusion facilities to protect them against Huanglongbing (HLB), a deadly disease caused by Candidatus liberibacter spp. and spread by the Asian citrus psyllid (Diaphorina citri). Faster year-round propagation is critical for citrus nurseries to offset their investment in new exclusion facilities, but nurseries currently face serious problems in terms of poor bud push and slow scion growth in fall-budded, container-grown trees. The purpose of this study was to explore the effect of supplemental LED lighting techniques on the photosynthesis and total non-structural carbohydrate (TNC) partitioning within citrus trees that is responsible for growth cessation during the fall. A total of 72 trees of Carrizo citrange rootstock with and without Clementine Mandarin scions, were placed in growth chambers during four photoperiods: T1, 10 h LED + 4 h extension of day length (EoD, 10 μmol·m−2·s−1); T2, 10 h LED with 1 h supplemental night interruption (NI); T3, 10 h LED with 10 h supplemental far-red (FR) lighting; and T4, controls (10 h LED). The LED light spectrum was adjusted to 90 red and 10 blue ratios. The trees were grown in the growth chambers at 21/13°C day/night temperatures and 80% RH for 12 weeks. Trees were harvested and separated into leaves, stems, and roots at the end of the experiment. Different tissues were oven dried, ground and analyzed for TNC. The results showed that NI and EoD resulted in significantly higher plant growth. Both NI and EoD allowed trees to accumulate lower levels of carbohydrates in the root system, thereby decreasing the root: shoot ratio. NI and EoD trees had lower root: shoot ratios for TNC than control and FR trees in both budded and unbudded trees, suggesting the storage of reserves in roots can be enhanced during shorter day length. Results also showed that NI and EoD photoperiods triggered phytochrome with low light intensity, which in turn induced a long day effect and further translocation of reserves from roots to aboveground parts to improve vegetative growth.

著者

Takuya Tetsumura Takashi Takita Shogo Funaki Kutaro Kusano Kasumi Kuhara Kotaro Manabe Kazuki Manabe Yasuhiro Udatsu Mitsuhiro Matsuo Shuji Ishimura Chitose Honsho

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-010, (Released:2022-08-09)

---

The growth and quality of the fruit from adult ‘Fuyu’ and ‘Hiratanenashi’ Japanese persimmon (Diospyros kaki Thunb.) trees that were grafted onto D. kaki seedlings (S), Rootstock-a (R-a), ‘MKR1’, and own-rooted (O-R) trees planted in February 2003 were observed from 2015 to 2021, when almost all of the trees entered stable, high-productive phases and the fruit quality was stable. The trees that were grafted onto ‘MKR1’ were still dwarfed but produced fruit efficiently. After disbudding took place, in the first half of stage I of the double sigmoid growth curve there was a certain period of time when the fruit of the ‘Hiratanenashi’ trees that were grafted onto ‘MKR1’ was lighter than the trees that had been grafted onto S. However, in the second half of stage I, the fruit of the former was heavier than that of the latter, and the flesh cells of the former were larger than that of the latter. In stage II and III, the fruit of the latter grew faster and became significantly heavier just before the harvest. The fruit growth of the ‘Fuyu’ trees that were grafted onto R-a was retarded compared to the growth of trees that were grafted onto ‘MKR1’ throughout most of the growing period. Heavy disbudding (HD) effectively increased the fruit weight of the ‘Hiratanenashi’ trees that were grafted onto ‘MKR1’ in a certain time period in stage I and in stage III compared to normal disbudding. HD also improved the fruit growth of the ‘Fuyu’ trees that were grafted onto ‘MKR1’, although this was not as effective as the ‘Hiratanenashi’ fruit growth. The weight of the harvested ‘Fuyu’ trees’ fruit increased in the following order: R-a, ‘MKR1’, O-R, and S. The ‘Hiratanenashi’ trees that were grafted onto ‘MKR1’ had the lightest fruit among the rootstocks, but the HD treatment for the trees that had been grafted onto ‘MKR1’ increased the fruit weight, and the difference disappeared. The soluble solids concentration of ‘Fuyu’ fruit was the highest in ‘MKR1’ and the lowest in R-a. ‘Hiratanenashi’ fruit had the highest concentration of soluble solids in S and the lowest concentration in O-R. The level of firmness of ‘Fuyu’ fruit flesh was the hardest in ‘MKR1’ and the softest in R-a, whereas the level of firmness of ‘Hiratanenashi’ fruit was the same among the rootstocks. Although the a* value of ‘Fuyu’ fruit skin color was the same among the rootstocks, the a* value skin color of ‘Hiratanenashi’ fruit was the highest in ‘MKR1’ and R-a and the lowest in S. These results suggest that the persimmon rootstock partly affects growth and quality of the fruit, although there are differences in the reactions between scion cultivars.

著者

Kentaro Ono Kaho Masui Ryutaro Tao

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-002, (Released:2022-08-09)

被引用文献数

3

---

Prunus (Rosaceae) includes many commercially important fruit crop species that exhibit self-incompatibility (SI), including sweet cherry (P. avium L.), Japanese apricot (P. mume Sieb. et Zucc.), Japanese plum (P. salicina Lindl.), apricot (P. armeniaca L.), and almond (P. dulcis [Mill.] D. A. Webb.). These species exhibit S-ribonuclease-based gametophytic SI, which prevents self-pollen tube growth in the pistil. The successful production of self-fertilized progeny accomplished by artificially overcoming the SI barrier has not been reported in Prunus, but self-compatible (SC) Prunus mutants with mutated pollen S determinant S haplotype–specific F-box (SFB) or pollen modifier M-locus encoded glutathione S-transferase-like (MGST) genes have been identified and used as SC cultivars and breeding stocks. In this study, we suppressed translation of SFB or MGST mRNA in self-pollen using antisense oligonucleotides to overcome the SI barrier in P. avium, P. mume, and P. salicina. Over the three years of the study, we obtained self-fertilized progeny of SI Japanese plum ‘Sordum’ only when SFB or MGST was knocked down. We also found that the average length of the self-pollinated pollen tube in the pistil of ‘Sordum’ was increased following treatment with an antisense oligonucleotide against SFB. This is the first report regarding the successful production of selfed progeny of Prunus obtained by disrupting SI. Our findings also provide evidence that the loss of function of SFB or MGST in Prunus pollen leads to SC.

著者

Keisuke Kagawa Takeru Gonai Hidenori Ichige Yutaka Fujita Iwao Terakado Akira Shimizu Tsuyoshi Iimura

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-362, (Released:2022-08-05)

---

In the replanting of Japanese pear, the growth of young trees after replanting is often suppressed due to soil sickness syndrome and white root rot. Pre-planting soil disinfection by hot water drip irrigation (HWD) treatment was developed as a control technique for white root rot. In addition, it is also expected to reduce the risk of soil sickness and promote tree growth. We therefore investigated the HWD treatment of pre-planting soil to promote the growth of young trees and obtain high yields at an early stage after replanting Japanese pear. HWD treatment of the pre-planting soil accelerated the growth of young trees in the first two years after planting and increased the yield in the third year compared to untreated soil. The HWD and water treatments of soil lowered the risk of soil sickness syndrome, suggesting that washing out growth-inhibiting substances with water promoted the growth of young trees. The HWD treatment flushed out nitrate-nitrogen from the soil and temporarily increased ammonia nitrogen due to decreased nitrifying activity one day after treatment. However, the change in nitrogen in the soil did not significantly affect growth, and the pH of the soil did not change significantly before and after the treatment. This suggests that the growth-promoting effect was not solely due to changes in soil chemistry, but rather due to the reduction in the risk of soil sickness. These results suggest that HWD treatment of pre-planting soil effectively reduces the risk of soil sickness and promotes the growth of young trees during the replanting of Japanese pear.

著者

Somsak Kramchote Patcharaporn Suwor

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-360, (Released:2022-08-02)

---

Two chili pepper (Capsicum annuum L.) cultivars ‘Super Hot’ and ‘Num Khao’ grown under field conditions in Thailand were sprayed with 0 (distilled water, control), 25, 50, 100, and 200 ppm chitosan after one week from transplanting and weekly thereafter for five weeks. Chitosan spray improved vegetative growth of both cultivars as measured by increased canopy size. It also increased the plant height of the ‘Super Hot’ cultivar and reduced leaf curl incidence in the ‘Num Khao’ cultivar. Leaf size and chlorophyll content were not significantly affected. Fruit were harvested from cultivars at the commercial maturity stage; that is, the red-ripe stage for ‘Super Hot’ and light green stage for ‘Num Khao’. From the four harvests at weekly intervals, chitosan treatment increased the ‘Super Hot’ yield because of greater fruit production and increased fruit size and there was a higher number of fruit per plant produced by the ‘Num Khao’ cultivar. Fruit color (L*, a*, b*, and sensory color) was not affected, but overall acceptability increased in response to chitosan spray due to improved size and quality of the ‘Super Hot’ cultivar and improved appearance, size and glossiness of the ‘Num Khao’ cultivar. Chitosan at 50 ppm appeared to be the optimum concentration to induce the above effects in both cultivars.

著者

Yang Yang Sho Ohno Yoshiyuki Tanaka Motoaki Doi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-367, (Released:2022-08-02)

---

Cut dahlia (Dahlia Cav.) flowers have recently become popular, but their marketability has been limited due to their poor vase life. The purposes of this study were to clarify the roles of leaves and inflorescences in the senescence of cut dahlias and to discuss the sink-source relationship between vegetative organs and inflorescences. The leaf life was maintained much longer (16.7 days) than the inflorescence life (7.4 days). The inflorescence life was not affected by removal of leaves, while leaf life was prolonged (19.6 days) by removal of inflorescences. Sucrose, glucose, fructose and small quantities of myo-inositol were detected in florets, and in addition to these sugars, nystose and 1-kestose were detected in stems and leaves. Total sugar levels of the middle florets (14.5 mg·g−1 FW on day 0) declined rapidly before their senescence. Total sugar levels of leaves (20.5 mg·g−1 FW on day 0) and stems (19.0–22.5 mg·g−1 FW on day 0) also decreased gradually during the postharvest period, but the levels decreased more slowly in deflowered cut stems. Sugar leakage from stem bases into vase water occurred during the initial few days. Removal of inflorescences increased sugar leakage significantly and promoted callus formation on the stem base. From these results, the inflorescence is considered to be a strong sink for carbohydrates, and stems and leaves serve as source organs. Heat girdling applied to the flower necks and petioles, also increased sugar concentrations of stem bases, thus resulting in higher sugar leakage and callus formation, although both heat girdling treatments shortened the leaf life. The sharp decrease in sugar levels of florets and an insufficient sugar supply are considered to be responsible for the short vase life of cut dahlias. It is suggested that these effects might be partly due to the blockage of sugar flows into petals through abscission layer development in the petal-ovary boundaries. Based on these results, we illustrate the senescing process of cut dahlia flowers in relation to sugar dynamism.

著者

Junjira Satitmunnaithum Hikaru Muroi Rina Ito Yuki Tashiro Antonius Febri Hendratmo Sayuri Tanabata Tatsuo Sato

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-380, (Released:2022-08-02)

---

Postharvest blossom-end enlargement (BEE) in summer cucumber has a serious economic effect in Japan. Previous studies suggested that BEE is influenced by cultivation conditions and temperature during transportation. In this study, the relationship between postharvest BEE and growth parameters in plants under various sink–source balances created by defoliation and fruit thinning was determined using a growth analysis technique. Cucumber (Cucumis sativus L. ‘Taibo I’) seedlings were transplanted into an outdoor field at Ibaraki University in 2019, and the harvested fruits were stored in plastic bags at 27°C. The occurrence of BEE, which was scored six days after harvest, was positively correlated with the field air temperature and cumulative duration of sunshine exposure from flowering to harvesting. Furthermore, high temperatures and extended sunshine exposure reduced the time from flowering to harvesting. However, excessive defoliation reduced BEE occurrence, most likely because of the increased time from flowering to harvesting, suggesting that early fruit maturation may be one of the causes of BEE. Therefore, principal component analysis was performed to understand the relationship between growth parameters and the occurrence of BEE in cucumber. The occurrence of BEE increased when the sink–source balance was inclined towards the source. Collectively, these findings indicate that high temperatures, extended exposure to solar radiation, and large leaf area with respect to the number of fruit set increase the occurrence of BEE, with pre-harvest fruit maturity probably related to its onset.

著者

Masahiro Kamimori Takeshi Isobe Hiroshi Yakushiji

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

vol.91, no.3, pp.337-344, 2022 (Released:2022-07-21)

参考文献数

27

被引用文献数

1

---

We aimed to determine the suitability of ‘Reikodai 1 go’ (BC1 from interspecific hybridization of Ficus carica L. and F. erecta Thunb.) as a ceratocystis canker disease-resistant rootstock for ‘Masui Dauphine’ fig. In this study, ‘Masui Dauphine’ was grafted onto ‘Reikodai 1 go’ and grown in 45 L pots under artificial soil infestation with Ceratocystis ficicola Kajitani et Masuya. Ceratocystis canker resistance, tree growth, and fruit production was assessed by comparing scion growth and fruit production in ‘Reikodai 1 go’-grafted and ‘Masui Dauphine’ own-rooted trees. No significant differences in the initial growth of the shoots (first year of planting) was observed between ‘Reikodai 1 go’-grafted and own-rooted trees. ‘Reikodai 1 go’-grafted trees demonstrated a tendency towards scion overgrowth. Soil inoculation with C. ficicola (nine times in three years; 2 L of suspension with 105 conidia/mL per pot) resulted in the death, or inhibited growth, of own-rooted trees. However, inoculated ‘Reikodai 1 go’-grafted trees revealed no growth inhibition and had growth similar to those of non-inoculated own-rooted and non-inoculated ‘Reikodai 1 go’-grafted trees. These results suggest that ‘Reikodai 1 go’-grafted trees were highly resistant to soil infestation with C. ficicola. No significant differences were observed between ‘Reikodai 1 go’-grafted trees with or without C. ficicola inoculation in terms of fruit production (considering fruit set, date of maturation, fruit length, width, fruit weight, estimated yield, skin color, and soluble solids content). When comparing fruit production of ‘Reikodai 1 go’-grafted and own-rooted trees, no differences were observed between the two in terms of fruit characteristics. Therefore, the use of ‘Reikodai 1 go’ as a rootstock is unlikely to cause considerable problems in the fruit production of ‘Masui Dauphine’ fig trees. Overall, shoot growth and fruit production of ‘Masui Dauphine’ grafted onto ‘Reikodai 1 go’ were not significantly different from those of the own-rooted trees. Therefore, it is expected that the introduction of ‘Reikodai 1 go’ rootstock for ‘Masui Dauphine’ production will be an effective approach for controlling ceratocystis canker.

著者

Takaya Ishii Miki Suto Natsuki Suzuki Hiroki Ikeda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-343, (Released:2022-07-14)

---

Onion (Allium cepa L.) is one of the most important vegetable crops in the world, and its cultivation is roughly divided into two types: autumn- (overwinter) and spring-sowing. In this study, we compared the changes in plant growth and bulb development of four short-day and intermediate-day onion cultivars under two years of varying environmental conditions to understand autumn-sowing cultivation and growth characteristics. A comparison of the growth parameters of the four cultivars throughout the growth period revealed that the increase in total leaf number and area, and plant height were almost completely inhibited in winter. In spring, these growth parameters increased rapidly in the early maturing cultivars and reached a plateau depending on the cultivar’s maturity type, as previously shown in spring-sowing cultivation. It is known that AcFT1 and AcFT4 play a key role in the bulb development of cultivated onions. Therefore, we conducted expression analysis of these genes for the four cultivars grown in the field and confirmed that AcFT1 was expressed following the maturity, irrespective of cultivation methods. We also analyzed AcGI expression in leaf blades, and a certain relationship between changes in bulb development and AcGI expression was observed. Correlation analysis of AcFT1 expression and total leaf number and area was conducted, and strong positive correlations were observed. In conclusion, our study demonstrated genetically that leaf number and area are important for inducing onion bulb development.

著者

Daiki Matsumoto Seita Shimizu Aoi Shimazaki Kohei Ito Satoshi Taira

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-385, (Released:2022-07-14)

被引用文献数

1

---

Akebia trifoliata is cultivated locally in few areas of Japan. Artificial pollination is considered indispensable for stable fruit production, as Akebia spp. exhibit self-incompatibility (SI). However, little is known about the reproductive physiology required for effective artificial pollination. In this study, we investigated the effects of self-pollen contamination on the fruit set of ‘Fuji Murasaki’ (A. trifoliata), one of the main lines in Yamagata Prefecture, Japan. Both the self- and cross-pollen tubes reached the base of the ovary and penetrated the ovules at 10 days after pollination, indicating that A. trifoliata exhibits late-acting SI. Self-pollination one day before cross-pollination completely inhibited fruit set, while self-pollination one day after cross-pollination did not inhibit fruit set in both 2016 and 2020, indicating interference in cross-pollination by self-pollen contamination. Fruit set rates for artificial pollination using a 1:1 mix of self- and cross-pollen were significantly lower than those that used non-contaminated cross-pollen in both 2016 and 2019, but were comparable when using a 1:1 mix of lycopodium powder and cross-pollen. The seed number of fruit resulting from mixed pollination was not significantly lower than that of fruit resulting from cross-pollination. Interestingly, 1:1 mixed pollination of self- and cross-pollen sometimes yielded abnormal fruits with an apex that remained pale and did not soften. These results suggest that excessive self-pollen contamination in artificial pollination may not be desirable for A. trifoliata fruit production.

著者

岩堀 修一 高橋 和彦

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.32, no.4, pp.299-302, 1963 (Released:2007-05-31)

参考文献数

4

被引用文献数

1 1

---

1. トマト福寿2号苗を用いて, 第1花房第1花が開花のとき, 40および45°Cそれぞれ1, 3, 6, 15時間高温処理を行なつた。2. 収量からみると40°C 1時間区は対照区と差がなかつた。それ以外の区では減収し, その程度は処理温度が高いほど, また処理時間が長いほど著しかつた。3. 人工発芽床による花粉の発芽試験の結果, 成熟花粉の発芽は, 40°C 1時間区でも非常に不良であつた。4. おのおのの蕾への高温の影響をみると, 開花8~9日前ごろの蕾が高温に対して最も弱く, 40°C 1時間でも障害をうけた。これと花粉発芽試験の結果から, 40°C 1時間程度の処理でも高温障害が現われると思われる。

著者

Megumi Ogawa Rihito Takisawa

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-368, (Released:2022-06-25)

被引用文献数

2

---

Artificially occurring parthenocarpy can be induced by exogenous application of plant hormones and is useful in the fruit production of many fruit crops and fruit trees. In cucumber (Cucumis sativus L.), a model species in the Cucurbitaceae family, the plant hormones auxin, gibberellin, cytokinin, and brassinosteroids are known to induce parthenocarpy. In tropical squash (Cucurbita moschata L.), synthetic auxins are known to induce parthenocarpy, but the effects of gibberellin, cytokinin, and brassinosteroids are still unknown. In addition, there are few published reports on the quality of parthenocarpic fruits induced by plant hormones in tropical squash, and the effects of these hormones remain largely unknown. In this study, we examined the effects of gibberellin, cytokinin, and brassinosteroids on the parthenocarpy of tropical squash and characterized the parthenocarpic fruits induced by the plant hormones. First, we evaluated fruit set and development in unpollinated fruits of ‘Kogiku’, a tropical squash cultivar, treated with gibberellic acid (GA3), a synthetic cytokinin-like substance, N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU), and brassinolide (BL). CPPU promoted parthenocarpy, but GA3 and BL did not, showing that cytokinin works as an important factor for parthenocarpy in tropical squash. Next, we investigated the quality of parthenocarpic fruits from ‘Kogiku’ induced by a synthetic auxin, 1-naphthylacetic acid (NAA), and CPPU. Total soluble solids and myo-inositol of NAA-treated parthenocarpic fruit were higher than those of pollinated fruits, whereas fructose of NAA-treated parthenocarpic fruit and fructose and glucose of CPPU-treated parthenocarpic fruits were significantly lower than those of pollinated fruits. These results showed that parthenocarpy of tropical squash induced by auxin and cytokinin had differing effects on fruit quality.

著者

Katsuhiko Inamoto Kaori Nagasuga Takayoshi Yano

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-372, (Released:2022-06-25)

---

We investigated the effects of CO2 enrichment on photosynthesis, growth, and dry matter accumulation in the Oriental hybrid lily ‘Siberia’. The photosynthetic rate increased as the CO2 concentration was elevated compared to the ambient level. The increase in the photosynthetic rate was greater in the low concentration range and lower in the high concentration range. The relationship between the light intensity-photosynthetic rate and temperature-photosynthetic rate was investigated under different CO2 concentrations. The entire light-photosynthesis and temperature-photosynthesis curves moved toward a considerably higher photosynthetic rate when the CO2 concentration was increased from 380 ppm to 1000 ppm. In contrast, when the CO2 concentration was increased from 1000 ppm to 2000 ppm, the increase in the entire light-photosynthesis curve was small. The relationship between the CO2 concentration and the maximum temperature point of the photosynthetic rate was unclear. We also cultured ‘Siberia’ lily plants with and/or without CO2 enrichment (1500 ppm) altered before (the early stage) and after (the late stage) the visible flower bud stage. The CO2 enrichment increased dry weights dry weight/fresh weight ratios of whole plants, and individual parts at flowering, resulting in improved cut flower quality and enlargement of the mother bulb and daughter bulblets. The effective period of CO2 enrichment was after the visible flower bud stage. In cases where CO2 enrichment was effective for dry matter accumulation, the dry matter distribution ratios of the mother bulb and daughter bulblets to the whole plant were high, and those of the leaves, stem, and flower buds were low. The relative growth rate and net assimilation rate from planting to the flowering stage were increased with CO2 enrichment applied after the visible flower bud stage, indicating that the dry matter accumulation and photosynthesis were enhanced. Finally, the issues that need to be addressed for applying practical CO2 enrichment technology to various lilies are discussed.

著者

Saeko Konishi-Sugita Kayo Sato Etsuko Mori Yuko Abe Miho Hazebayashi Kenji Gomi Mitsuaki Tabuchi Gan Kisaki Tetsuo Fukuda Tetsuro Manabe Kohei Hamano Mamoru Ohtani Katsuhiko Suezawa Kazuya Akimitsu Ikuo Kataoka

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-340, (Released:2022-06-15)

---

The pathogenic bacterium Pseudomonas syrinage pv. actinidiae causes bacterial canker disease, which is the most damaging disease afflicting kiwifruit (Actinidia chinensis). The most prevalent strain is biovar 3 (Psa3), which is highly pathogenic. Therefore, Psa3-resistant varieties of kiwifruit are urgently needed. A previous study reported that Actinidia rufa, a wild Japanese species related to kiwifruit, is highly resistant to Psa3. Genome-wide DNA markers may be useful to locate the loci that confer Psa3 resistance. Therefore, in the present study, we used published kiwifruit genome sequence information to design 1,101 simple sequence repeat (SSR) markers covering the entire kiwifruit genome in silico. We next examined DNA polymorphisms in more than 1,000 polymerase chain reaction products for potential use as SSR markers among A. rufa Fuchu and A. chinensis FCM1, a pollen-providing parent Fuchu A. chinensis male 1, and other kiwifruit cultivars in order to develop Psa3 resistant kiwifruit cultivars. We finally obtained 351 polymorphic markers, in the entire kiwifruit genome, which can be applied to produce next-generation kiwifruit cultivars, including Psa3-resistant cultivars.

著者

細田 浩 岩橋 由美子 與座 宏一

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.69, no.4, pp.512-516, 2000-07-15 (Released:2008-01-31)

参考文献数

17

被引用文献数

2 3

---

カットレタスの褐変に及ぼすネギ類搾汁液の影響を調べ, 以下の結果を得た.1. カットレタスをネギ類の搾汁液に短時間浸漬すると貯蔵中のカットレタスの褐変が抑制され, 特にタマネギとニンニクの搾汁液の変色抑制作用が強かった.2. タマネギの搾汁液へのカットレタスの浸漬時間は3分間で十分な変色抑制効果を示した.3. タマネギの品種比較では試験した11品種中'北もみじ86'の変色抑制作用が最も強かった.部位別の比較では可食部全体に変色抑制作用が認められたが, 中心部ほど作用が強い傾向があった.4. タマネギ搾汁液を加熱した時の変色抑制作用の低下はわずかであったが, タマネギを加熱した後で磨砕, 搾汁した搾汁液には変色抑制作用がなく, カットレタスの変色を抑制する成分はタマネギの磨砕, 搾汁過程で酵素作用によって生成する成分であろうと推測した.

著者

Atsu Yamasaki Junko Kaneyoshi Michiharu Nakano Akira Kitajima

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-284, (Released:2022-06-01)

---

Mukaku Kishu–type seedlessness in citrus (Citrus L.) is characterized by the formation of small and edible seeds (type A seeds) with an immature seed coat and arrest of embryo development at an early stage. We investigated the effect of high temperature on embryo and seed development in the Mukaku Kishu–type seedless cultivar ‘Southern Yellow’ over a period of four years. In outdoor-grown trees, embryos at the zygote and proembryo stages were observed at 10 weeks after pollination (WAP), and embryo development was largely arrested at 18 WAP; as a result, only type A seeds formed. In glasshouse-grown trees, globular-stage embryos were observed at 10 WAP, and globular- to cotyledon-stage embryos developed by 18 WAP. The day temperature in the glasshouse was higher than outdoors. Seeds developed in the fruit of trees transferred into a glasshouse at 0–2, 0–4, or 2–4 WAP, but not 4–8 WAP. High temperature before flowering had no effect on seed development. We conclude that high temperature at 0–4 WAP releases the arrest of embryo development after 10 WAP in ‘Southern Yellow’.

著者

Hiroki Matsuo Keiji Mine Taro Sano Hirotsugu Yoneda Yosuke Yoshioka

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-363, (Released:2022-05-31)

被引用文献数

2

---

Anthracnose, caused by the fungal pathogen Colletotrichum orbiculare, is one of the most severe diseases in watermelon (Citrullus lanatus) cultivation in Japan. Genetically conferred host resistance is the best way to control it. To develop new cultivars with high resistance, identification of promising sources of resistance is important. We focused on an old Japanese cultivar, ‘Tanso Teikosei’ (NR28), with high resistance, preserved at the Nara Prefecture Agricultural Research and Development Center, evaluated its resistance to diverse C. orbiculare strains distributed in Japan, and revealed the inheritance of its resistance. NR28 and two other accessions were resistant to the highly virulent MAFF 306737 strain. NR28 was also resistant to 16 other strains collected from various regions of Japan. Many strains caused severe symptoms and wilting in susceptible accessions, including the popular Japanese F1 cultivar WF01. CAPS marker analysis indicated that NR28 and the two other resistant accessions were homozygous for the resistance allele of Cla001017, previously reported as the gene responsible for resistance to US race 1. Susceptible accessions were homozygous for the susceptibility allele at Cla001017. Segregation analyses using F2 and BC1F1 lines derived from crosses between NR28 and a susceptible accession suggested that the dominant mutant allele of Cla001017 caused the high resistance of NR28. In contrast, NR28 and other resistant accessions homozygous for the resistance allele of Cla001017 were highly susceptible to two strains sampled in Iwate Prefecture. This suggests that these strains have overcome the Cla001017 resistance allele, as have strains of C. orbiculare classified as US race 2. NR28 and the two other resistant accessions are promising materials for breeding resistance in diverse C. orbiculare strains distributed in Japan that have similar pathogenicity to US race 1. The CAPS marker that we designed in this study offers efficient analysis for watermelon breeding.

著者

Tadahisa Higashide

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-R019, (Released:2022-05-31)

被引用文献数

4

---

The fresh fruit yield of tomatoes (Solanum lycopersicum) is determined by yield components and related traits. In low-truss cultivation in Japan, light use efficiency in the same cultivar is not significantly affected by plant density or seedling stage at transplanting. Total dry-matter production equals light use efficiency × light intercepted by plants. Light interception is determined by leaf area index and the light extinction coefficient in the plant canopy. Light use efficiency is determined by leaf photosynthetic rate and light extinction coefficient. Light use efficiency is expressed as a function of daytime CO2 concentration. The high yield of modern tomato cultivars in the Netherlands is due to an increase in total dry matter production of plants, not to an increase in dry matter partitioning of fruits. An increase in the photosynthetic rate and a decrease in the light extinction coefficient may have increased light use efficiency among Dutch cultivars. Although modern Japanese cultivars have a high content of both water and soluble solids of fruits, yield has not increased. Since the yield of greenhouse tomatoes in Japan has increased little since the 1980s, Japanese researchers have attempted to improve the yield using current Japanese cultivars. Crop growth models can help management decisions on cultural practices, control of greenhouse climate, fertilization, and irrigation. Several models of tomato growth including TOMSIM and TOMGRO have been developed. A growth model based on the relationships among yield components and related traits has been developed to predict dry matter production and yield of greenhouse tomatoes. The model recommended a leaf area index with the highest dry matter production at a certain solar radiation. To improve yield of greenhouse tomatoes by using the model, a one-year experiment was carried out in a greenhouse. The annual yield of tomatoes with Brix at least 5° was at least 50 kg·m−2 for a popular Japanese cultivar, ‘CF Momotaro York’. For the near future, the growth models show promise for growers in helping yield improvement and crop management in greenhouses.