著者

Sho Yamamoto Yutaka Yamagiwa Zentaro Inaba Takashi Handa

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

vol.87, no.1, pp.115-123, 2018 (Released:2018-02-06)

参考文献数

33

被引用文献数

2 2

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Lilium japonicum Thunb. which has pink or white-colored funnel-like flowers, is distributed in Kyushu, Shikoku, and the western part of Honshu, the main island of Japan. L. auratum Lindl. which has large white flowers with yellow central stripes and red spots, is distributed in the eastern part of Honshu. Natural hybridization of these two species has only been found on the Izu Peninsula of Honshu. However, details of the variation and hybridity of the interspecific hybrid population of these species on this peninsula remain unknown. In the present study, we conducted a morphological examination using 43, 21, and 90 individuals of L. japonicum, L. auratum, and the putative hybrid, respectively, from six, four, and ten populations of the Izu Peninsula, respectively. In addition, we performed simple sequence repeat (SSR) analysis using 47, 41, and 106 individuals of L. japonicum, L. auratum, and the putative hybrid, respectively, from six, four, and ten populations, respectively. Putative hybrid populations that resembled L. japonicum in morphology and SSR profile were found in the southern to eastern part of the peninsula, whereas those that resembled L. auratum and those exhibiting an intermediate morphology and SSR profile were found in the southern part of the peninsula. Large morphological variations exist in putative hybrid in the southern population, and interspecific hybridization has occurred in the southern and eastern populations. These results suggest that the center of natural hybridization is located in the southern part of the Izu Peninsula.

著者

Shinichi Furuyama Hideki Okamoto Tatsuru Jishi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-003, (Released:2022-12-28)

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Borecole (curly kale) was cultivated without heating during autumn and winter in a multi-film-covered greenhouse in Hokkaido, Japan. Borecole survived even when the greenhouse air temperature dropped to −6.2°C with an accompanying drastic increase in Brix value. This rapid increase of Brix value was observed under conditions where the minimum air temperature in the greenhouse was less than 0°C. Cold temperatures caused the plant to freeze, inducing extracellular freezing. Although the Brix value increased at low temperatures irrespective of leaf order, the Brix values for leaves of lower order, at the top of the plant, were much larger than the higher order leaves, closer to the base of the plant. Leaf Brix values started to increase when the average minimum temperature was 1.3°C or less for 10 days before harvest. Moreover, the nitrate concentration, reported to correlate with bitterness intensity, decreased at low temperatures. These results revealed that leaves with reduced bitterness and improved sweetness can be produced in low temperatures from the upper portions of borecole plants.

著者

Orrawan Pleumjit Thanachok Taticharoen Jingtair Siriphanich

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-021, (Released:2022-12-28)

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Young coconut shell cracking is a significant problem reported during trimming and polishing. By studying the shell structure, fruit development, pressure inside the shell (internal pressure) of young fruits, dissolved carbon dioxide in the coconut water and cracking incidence, as well as postharvest treatments to manipulate the pressure and carbon dioxide concentration, it was revealed that cracking depended on the physical property of the shell and the internal pressure. Cracking was principally found on the large carpel where the shell was the thinnest. The growing area presenting a high cracking incidence was found to have fruits with a thinner shell than fruits from a nearby area. The younger fruits had a weaker, thinner shell and high internal pressure. Once the fruits were 28 weeks old, the internal pressure dropped to slightly above atmospheric pressure. The level of internal pressure did not depend on rainfall or growing area. However, postharvest heating, dipping in water and exposure to carbon dioxide increased the internal pressure. To reduce shell cracking incidence, it is recommended to delay harvesting to allow shell strengthening, delay the trimming and polishing processes to allow water loss from the fruit and reduce the internal pressure. Dipping fruit in an anti-browning solution should also be brief to avoid water absorption.

著者

Chia Ting Han Yu Sung Ming-Tung Hsueh

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-387, (Released:2022-12-28)

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Winged bean seeds require imbibition treatment to ensure fast and uniform germination. Seed soaking has been commonly used; however, it is unclear if this is a safe method for winged bean seeds. Solid matrix priming (SMP) is an imbibition treatment that combines seeds, a matrix and water in a specific ratio. It allows seeds to imbibe under controlled water uptake. We investigated the effect of imbibition treatments on seed germination of white winged bean. Soaked seeds had significantly reduced germination and emergence as a result of imbibition injury due to rapid imbibition. SMP at a seed: vermiculite: water ratio of 7:12:9 (w/w/w) was the most effective treatment that allowed seeds to imbibe slowly without the occurrence of imbibition injury. SMP significantly reduced the mean germination time from 4.63 days to 2.01 days, and mean emergence time from 7.21 days to 5.78 days, compared to the control, as well as having a high germination rate of 98% and uniform emergence. The fast imbibition rate of white winged bean seeds was likely the result of cracks present on the permeable seed coat.

著者

Kenji Sakurai Hiroshi Iwanami

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-009, (Released:2022-12-15)

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Based on hand pollination, 217 crabapple cultivars were examined to determine their self-fruitfulness potential. One hundred and six cultivars failed to self-pollinate for fruits set. More than 50% self-pollinated fruit were obtained from 29 cultivars. Especially, the fruit set of ‘Jiringo’, ‘Karafutozumi’, ‘Katherine Crab’, Malus hupehensis, M. scheideckeri, ‘Mary Porter Crab’, ‘Mokoto’, ‘Nepal Apple Collections No. 85-I-74-3 86090-3’, ‘Scheidecker Crab’, ‘Silver Moon Crab’, ‘Tachikaido’, and ‘Tea Crab 81105’ were more than 50% by self-pollination over two years. ‘Jiringo’, ‘Katherine Crab’, ‘Mary Porter Crab’, ‘Scheidecker Crab’, and ‘Tachikaido’ have the potential to be self-compatible cultivars because their self-pollinated fruits contain complete seeds. Non-pollinated fruits of M. scheideckeri, ‘Nepal Apple Collections No. 85-I-74-3 86090-3’, and ‘Tea Crab 81105’ may contain apomictic seeds. Moreover, self-pollinated fruits contained seeds and non-pollinated fruits contained no seeds, suggesting that ‘Karafutozumi’ and ‘Mokoto’ may be self-compatible and parthenocarpic. The study findings not only provide breeding material for self-compatible apple cultivars, but also have led to the discovery of new apomictic and parthenocarpic research materials.

著者

Ko Motoki Yu Kinoshita Ryohei Nakano Munetaka Hosokawa Tetsuya Nakazaki

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-018, (Released:2022-12-15)

被引用文献数

1

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Floral induction by grafting without vernalization treatment (NV grafting method) has potential to shorten breeding times and to diversify the seed production of cabbage, an important leafy vegetable with a long and absolute low temperature exposure requirement for its floral induction. However, it is unknown whether the NV grafting method can be actually used for cabbage breeding and seed production. This is because the NV grafting method’s effect on the field performance of obtained progenies has not been investigated, as opposed to the conventional floral induction method by vernalization treatment. Therefore, in this study we compared the effects of two different floral induction methods on the agricultural traits of the obtained progenies. Two clonal lines of ‘Watanabe-seiko No.1’ cabbage were used for the experiment. In the two-year field experiment, we observed a consistent effect of clonal lines on vegetative growth; however, almost no effects of the floral induction methods on either vegetative or reproductive growth were observed. This was further supported by similar expression levels of FLOWERING LOCUS C homologs in the progenies at the young seedling stage. Pollen production and seed formation of the progenies were confirmed regardless of the floral induction method. In conclusion, cabbage seeds obtained by the NV grafting method are likely to show the same traits as those obtained by the conventional vernalization method. This indicates the direct applicability of this method to cabbage breeding and seed production.

著者

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-R001, (Released:2022-12-13)

被引用文献数

5

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Self-incompatibility in Citrus species is an important trait related to fruit set and seed formation. In particular, self-incompatible citrus varieties combined with sufficient parthenocarpy produce seedless fruits. The characteristics of self-incompatibility have been studied for many years, and essential traits, such as pollen tube elongation behavior and self-incompatibility genotypes, have been characterized. Recently, it has been shown that the genetic mechanism of self-incompatibility in citrus varieties is S-RNase-based gametophytic self-incompatibility. To date, 18 S-RNases (17 self-incompatible alleles and 1 self-compatible allele) have been identified. The DNA markers for S-RNases can enable the early identification of self-incompatibility/compatibility status. The expression of self-compatibility in Citrus species is ascribed to the presence of the self-compatibility Sm allele, which is a defective S-RNase, and to the suppression of S-RNase expression. Polyploidization induces self-compatibility in Citrus species: Citrus tamurana ‘Hyuganatsu’ is substantially self-incompatible; however, its bud mutation, ‘Nishiuchi Konatsu’, is self-compatible. ‘Nishiuchi Konatsu’ is diploid; however, it forms unreduced pollen, which causes the breakdown of self-incompatible reaction when self-pollinated because of a competitive interaction within the same individual. In addition, after fertilization by unreduced pollen, seed formation is also inhibited by triploid block caused by interploid hybridization between diploid pollen and haploid egg cells. Therefore, ‘Nishiuchi Konatsu’ shows self-compatibility regardless of the self-incompatibility haplotype and produces fruits with few seeds. The seedlessness trait could be beneficial for citrus breeding in the future; however, the genetic mechanisms involved in the expression of this trait remain unclear. This review focuses on the recent advances in the genetics of self-incompatibility in citrus plants, implicating the mechanisms involved in self-incompatibility and their applications for achieving the desired trait of seedlessness in citrus fruits.

著者

Abdul H. Kazimi Oscar W. Mitalo Azimullah Azimi Kanae Masuda Chikara Yano Takashi Akagi Koichiro Ushijima Yasutaka Kubo

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-012, (Released:2022-11-25)

被引用文献数

2

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A major challenge in terms of commercializing 1-methylclopropene (1-MCP) to extend the storage life and control physiological disorders in European pears is that it irreversibly inhibits fruit ripening in some cultivars, particularly flesh softening that is necessary for optimal consumption quality. In this study, we examined the effect of 1-MCP pretreatments on fruit ripening and associated transcriptomic changes in ‘La France’ (Pyrus communis L.) pears during storage at 20°C and 5°C. Compared to non-treated controls, 1-MCP pretreatment suppressed fruit respiration and ethylene production rates, and markedly delayed flesh softening. Normal ripening (ethylene production and flesh softening to eating quality firmness) was observed in 1-MCP treated fruit after 42 d at 20°C, and 112 d at 5°C. Subsequent RNA-Seq analysis revealed that 6,427 genes, including those associated with ethylene biosynthesis (ACS1, ACS1b, ACO1, and ACO2), cell wall degrading enzymes (PG3, β-GAL, EG, and EXP1), and transcription factors (AGL18 and NAC29) were up- or down-regulated in non-treated fruit both at 20°C and 5°C. The expression patterns of these genes were disrupted by 1-MCP pretreatment, but up- or down-regulation was also observed when ethylene was detected in 1-MCP-treated fruit. Together, these findings demonstrate the potential for practical use of 1-MCP to extend storage life in ‘La France’ pears given that (i) a single application markedly extended storage life to 56 d at 20°C and 112 d at 5°C, and (ii) treated fruit could regain their softening capacity, thus eliminating previous irreversible ripening blockage concerns.

著者

Manato Ohishi Megumu Takahashi Machiko Fukuda Fumio Sato

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-022, (Released:2022-11-22)

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The demand for broccoli (Brassica oleracea L. var. italica) is increasing for use as fresh produce and for use in the processing industry. Therefore, growth prediction technology is required for its stable production. In this study, several cultivations of experiments were conducted to clarify the critical characteristics of the parameters needed to predict the growth of broccoli in a dry matter production model. The extinction coefficient was determined based on the leaf area index and intercepted solar radiation rate. Radiation-use efficiency was demonstrated using a linear function of the accumulated solar radiation intercepted amount and the total dry weight above-ground. The distribution of dry matter to the head and stem was indicated by the sigmoid function of the accumulated average temperature. The dry matter percentage of the leaf, dry matter percentage of the head and stem, and the ratio of leaf area to the fresh weight of the leaf were represented by a power function with dry weight above-ground. The fresh weight above-ground (R2 = 0.92) and the fresh weight of the head and stem (R2 = 0.98) were highly correlated with the estimated and observed values. Verification was performed using the developed growth model. As a result, the error between the harvest date and the predicted harvest date could be forecasted to within 4 days and the error in the fresh weight of the head could be predicted with an accuracy of −0.3 ~ +7.7 g·plant−1.

著者

Chang-Sheng Chien Wei-Ling Chen Yu Sung

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-386, (Released:2022-10-18)

被引用文献数

1

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In Taiwan, the early harvesting of young ginger is a cultivation technique for domestic ginger, which can be harvested early by forced sprouting. At present, ethylene is used as the sprouting agent. Despite its favorable sprouting effect, the technique can still be improved. Experimental results revealed that 1% citric acid, 300-ppm and 450-ppm ethephon treatments effectively facilitated the formation of 2.4, 2.4, and 2.6 large buds (diameter of ≥ 1 cm), respectively, in the rhizome. The stems and leaves of the ginger seed rhizomes that were subjected to forced sprouting emerged from the soil one month after planting, and emergence rates of 46.7% and 83.3% were achieved using citric acid and ethephon, respectively. Although the fresh weight of semi-matured ginger rhizomes obtained by forced sprouting treatment was lower, the results can still provide a reference for the early harvest of young ginger in Taiwan. Among the examined gingers, semi-matured ginger that was subjected to 50-ppm GA3 forced sprouting treatment exhibited the most favorable growth, and the average weight of its rhizomes reached 1,567 g, which was not significantly different from the weight obtained by conventional cultivation, but significantly greater than that obtained by other treatments. The GA3 forced sprouting treatment was not very effective, but it had an excellent effect on improving the yield of semi-matured ginger rhizomes. In the future, this treatment will be conducive for the production of semi-matured or matured ginger.

著者

Mizuho Itoh Yasunaga Iwasaki Dong-Hyuk Ahn 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-381, (Released:2022-09-30)

被引用文献数

1

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The relationship between fruit Brix and the electrical conductivity (EC) of the nutrient solution was investigated under gradually increasing EC conditions to predict and control tomato fruit Brix in commercial greenhouses in Japan. Based on the three experiments, fruit Brix was significantly and highly correlated with the cumulative EC of the drainage during the period from anthesis to harvest (cECd). This relationship followed a linear regression function. We then modelled fruit Brix based on cECd and validated this model to predict and control fruit Brix in four other experiments in different growing seasons using two cultivars, slab substrates, and irrigation systems. Using this model, we calculated the target cECd (cECdt) to achieve a target fruit Brix of 6% or higher and used cECdt as an indicator to manipulate the EC of the nutrient solution. In the validation experiments, cECd was lower than cECdt at the beginning of harvest in all experiments. cECd reached cECdt at 72.3–214.0°C·day after the first harvest. When cECd was higher than cECdt, more than 86.9% of the fruit had a higher than Brix 6%. In addition, the marketable yield was higher than 88.2%. RMSEs between the observed fruit Brix and predicted fruit Brix were 0.60–1.25. These results indicate that our model can predict and control fruit Brix.

著者

Takuya Morimoto Yunosuke Matsuda Ryo Sekiguchi Akihiro Itai

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-383, (Released:2022-09-30)

被引用文献数

1

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The development of intergeneric hybrids for horticultural crops has been attempted to introduce new quality and resistance traits and to enlarge the gene pool. Interspecific and intergeneric hybridization are often hindered by incompatibility reactions occurring at various stages of hybridization, from early pollination to initial growth, and the reproductive stages of the progeny. In this study, we investigated intergeneric and interspecific cross-compatibility among six species in the tribe Maleae (Rosaceae), namely, Pyrus communis (European pear), P. pyrifolia (Japanese pear), Malus × domestica (apple), Eriobotrya japonica (loquat), Cydonia oblonga (quince), and Pseudocydonia sinensis (Chinese quince). In vivo pollen tube growth tests showed the presence of a postmating, prezygotic barrier in many cross-combinations, in which cross-compatibility was regulated by both genetic distance and crossing direction. Strong hybridization barriers were observed in pollen tube growth and fruit setting when intergeneric hybridization was performed with E. japonica, a species phylogenetically distant from the others studied. Different compatibility reactions in reciprocal crosses were observed in some intergeneric hybridizations; C. oblonga as a pollen donor was incompatible with P. sinensis, whereas the reciprocal cross was compatible, resulting in the development of hybrid seedlings. Furthermore, the pollen tube growth rate differed among Pyrus species when pollinated on the apple pistils, suggesting divergence of cross-compatibility response in a specific linage. Factors affecting intergeneric hybridization are discussed with reference to the genetic distance between species and morphological characteristics such as pistil length. Our comprehensive assessment of intergeneric cross-compatibility will help provide a way to overcome crossing barriers and develop new hybrid crops in the tribe Maleae.

著者

Nadya Syafira Pohan Gian Alfan Munawar Khalil Putra Bahagia Rayhan Hayati Yusuf Haidar Nurul Hadisah Mika Onouchi Ryosuke Shirono Yoshinori Kohno Ayane Hamada Tae Maruishi Shinkai Hachisu Kanami Homma Sabaruddin Zakaria Elly Kesumawati Sota Koeda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-015, (Released:2022-08-30)

被引用文献数

1

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Pepper yellow leaf curl disease (PepYLCD) caused by begomoviruses is one of the most devastating diseases affecting pepper (Capsicum spp.) production worldwide. In our previous study, a loss-of-function allele, pepy-1, encoding messenger RNA surveillance factor Pelota was identified as a begomovirus resistance gene from a C. annuum cultivar BaPep-5. In this study, to investigate the effectiveness of pepy-1 conferred resistance against begomovirus in the field, we conducted a three-year evaluation under natural field conditions in Indonesia. The lowest PepYLCD incidence and significantly higher fruit productivity were observed in BaPep-5 when compared to six other commonly cultivated pepper cultivars. The subsequent comparison between BaPep-5 and the susceptible BaPep-4 showed that pepy-1 slowed down the disease onset and progression, resulting in a higher fruit productivity trait in the field. Multiple comparison analyses using an F2 population obtained by crossing BaPep-5 with BaPep-4 showed that the pepy-1 homozygous individuals had significantly higher fruit productivity, twice than those of the Pepy-1 homozygous or heterozygous individuals. In conclusion, the introgression of pepy-1 is effective to reduce the economic loss of pepper fruit production under natural field infection of begomoviruses.

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

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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)

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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)

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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

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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)

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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)

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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)

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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.