著者

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

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-049, (Released:2017-01-07)

被引用文献数

22

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Tomato yellow leaf curl disease caused by begomoviruses is a serious threat to tomato (Solanum lycopersicum L.) production. If begomoviruses, transmitted by whitefly (Bemisia tabaci), infect tomato plants during early growth, production can be almost entirely lost. Tomato yellow leaf curl Kanchanaburi virus (TYLCKaV), a bipartite Begomovirus, is emerging as an important threat to solanaceous crop production in Southeast Asia. The lack of mechanical transmission of some begomoviruses is a major experimental constraint. In this study, an agroinoculation method using TYLCKaV in tomato plants was established. Partial tandem repeats of TYLCKaV DNA A and DNA B were constructed and cloned to a binary pGreenII vector, and their infectivity was tested. Co-inoculation of TYLCKaV DNA A and DNA B to Nicotiana benthamiana L. produced typical begomoviral symptoms, and both of the viral DNA components accumulated in the upper uninoculated leaves, suggesting systemic infection of TYLCKaV. Two agroinoculation methods were conducted on tomatoes. First, excised sections of tomato shoots were agroinoculated with a soaking procedure. Although two Agrobacterium tumefaciens strains were tested, approximately 40% of inoculated plants only showed viral symptoms for EHA105. Second, agrobacterium from a cultured petri dish was directly inoculated with a colony inoculation procedure. When EHA105 was used, approximately 92% of inoculated plants showed viral symptoms. Sequencing the recovered viral DNA from the upper uninoculated leaf clarified that TYLCKaV had successfully infected the tomato plants. The colony inoculation procedure is labor-saving, and viral symptoms develop in susceptible tomato plants within approximately a month from sowing the seeds. This method could contribute to simple and speedy evaluation of TYLCKaV resistance of tomato plants.

著者

Yasuhisa Tsuchida Hiroshi Yakushiji

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-040, (Released:2016-11-22)

被引用文献数

5

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With the continuing trend of global warming, the adverse impact of high temperature and the inevitably accompanying drought stress on the growth of Japanese apricot trees (Prunus mume Siebold et Zucc.) are of concern. Therefore, the effects of these factors on photosynthesis and carbohydrate translocation were analyzed. An investigation was conducted at average daytime temperatures of 24°C, 30°C, and 34°C under both irrigated and drought conditions. The 34°C temperature was higher than the open air temperature by 5°C. Stable isotope 13C was administered to trees to determine carbohydrate positioning. Under the drought stress condition, the photosynthetic rate declined accompanied by temperature elevation, and at the highest temperature of 34°C, 13C concentrations in the twigs and roots were lower than those in the irrigated trees at 24°C. Two-way analysis of variance revealed a trend of 13C translocation to the young organs above ground, and old organs, while roots were affected by water status, temperature, and their combination, respectively. In the irrigated trees, the photosynthetic rate reduction was not detected, even at higher temperatures. However, translocation incompetence reflecting a decline in 13C concentration in the roots was observed at 34°C. These results indicate that the permissible diurnal average temperature during summer for the growth of Japanese apricot trees is approximately up to 30°C, and in the temperature range around this irrigation is helpful to facilitate regular functioning of carbohydrate translocation under drought stress conditions.

著者

Hyun Jin Kim Ah Ram Cho Kyoung Sub Park Yoon Jin Kim

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-027, (Released:2016-11-11)

被引用文献数

11

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To increase the photosynthesis of crop and improve plant quality, we evaluated the effect of elevated CO2 on vegetative growth and flowering in Phalaenopsis Fuller’s Pink Swallow. Plants were exposed to 450 (control), 800, 1600, and 2400 μmol·mol−1 CO2 for 31 weeks. The number of leaves, leaf length, and leaf width displayed greater increases in plants grown under 1600 and 2400 μmol·mol−1 CO2 than in plants grown under 450 and 800 μmol·mol−1 CO2. The times to leaf initiation were reduced to 90.7 and 85.8 days in plants grown under 1600 and 2400 μmol·mol−1 CO2, respectively, compared with that of the control, 177.1 days. The leaf elongation rate was significantly increased in plants grown under 1600 and 2400 μmol·mol−1 CO2 compared to plants grown under 450 and 800 μmol·mol−1 CO2. Plants grown under 1600 μmol·mol−1 CO2 had the highest total number of flower buds among all plants grown under the four tested CO2 concentrations. Leaf injuries were not observed in any plants regardless of CO2 concentration, but flower bud abortion and bud withering were observed in CO2-enriched plants, especially in plants grown under 1600 and 2400 μmol·mol−1 CO2. Plants subjected to long-term CO2 elevation of over 800 μmol·mol−1 displayed increased biomass production despite a concomitant reduction in the number of buds. These results showed that 1600 and 2400 μmol·mol−1 CO2 significantly enhanced the vegetative growth of Phalaenopsis. However, long-term exposure to high CO2 concentrations can adversely affect the flowering of Phalaenopsis, and result in reduced flower production and increased flower bud abortion.

著者

Keisuke Nonaka Hiroshi Fujii Masayuki Kita Takehiko Shimada Tomoko Endo Terutaka Yoshioka Mitsuo Omura

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-026, (Released:2016-10-04)

被引用文献数

14

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To protect the rights of breeders of the major citrus cultivars developed under breeding programs by the national institute of Japan, we developed a method of cultivar identification based on cleaved amplified polymorphic sequence (CAPS) markers, and used it to evaluate their identity and parentage. We selected 19 CAPS markers that had a single-locus origin and moderate polymorphism, and used them to construct genotyping data for 59 citrus cultivars (including American accessions), local varieties, and selections. Of the 19 CAPS markers, 8 were sufficient to discriminate among all accessions except ‘Mato’ buntan (Citrus grandis Osbeck) and ‘Hirado’ buntan (Citrus grandis Osbeck). Among the 33 Japanese cultivars, the parentage of 30 agreed with that reported, but ‘Setoka’, ‘Southern Red’, and ‘Reikou’ had discrepancies at one or more loci. Using 15 to 18 CAPS markers to validate the putative parentage revealed that the seed parent of ‘Setoka’ was ‘KyEn No. 4’, not ‘Tsunonozomi’, and the pollen parent of ‘Southern Red’ was ‘Osceola’, not ponkan (C. reticulate Blanco). The seed parent of ‘Reikou’ remains unknown.

著者

Hiroki Ikeda Tomoki Shibuya Manabu Nishiyama Yoshihiro Nakata Yoshinori Kanayama

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-015, (Released:2016-09-28)

被引用文献数

21

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Calcium (Ca2+) concentration, early fruit growth, and expression of Ca2+-movement-related genes were analyzed during early fruit development in the tomato, which is the most important stage regarding the incidence of blossom-end rot (BER), to investigate the physiological mechanisms affecting the occurrence of BER. We used tomato introgression line IL8-3 with a chromosome segment from a wild relative (Solanum pennellii) because this line shows lower incidence of BER compared with the parent cultivar ‘M82’ (S. lycopersicum), as described previously. Ca2+ concentration in fruit and leaves was higher in IL8-3 than in ‘M82’, whereas no significant differences were observed between Ca2+ concentration in roots and stems of ‘M82’ and IL8-3. These results suggested that a Ca2+ transport property is an essential factor for the lower incidence of BER in IL8-3. IL8-3 fruit showed a lower growth rate than ‘M82’, which could result in preventing the occurrence of BER. The expression of genes encoding cation exchangers, Ca2+-ATPases, a Ca2+ channel, and Na+/Ca2+ exchangers, was higher in IL8-3 fruit than in ‘M82’ fruit, suggesting active Ca2+ movement in IL8-3. All results in this study could be related to physiological mechanisms accounting for the lower incidence of BER in IL8-3.

著者

Hsiang-Yi Huang 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-159, (Released:2016-09-27)

被引用文献数

10

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The objective of this study was to determine the genetic model of fruit color in the bitter gourd (Momordica charantia L.). Six generations (P1, P2, F1, F2, BCP1, and BCP2) in the hybrid set “MS 41 × MS 47” were used to estimate the genetic effects via generation mean analysis (GMA). The fruit color of the F1 population was green implying the green color was dominant over the white color. The fruit color of the F2 population showed a continuous distribution from white to dark green indicating this trait was controlled by quantitative genes. Genetic analyses using the Royal Horticultural Society scoring system (RHS score) fitted the three parameters model (χ23 = 1.59, P = 0.6607) and showed significant to highly significant additive and dominance effects, respectively. The GMA results of the six parameters model revealed a significant additive effect on chlorophyll b concentration. Chlorophyll a and total chlorophyll concentrations were nonsignificant in all parameters. The magnitudes of additive and additive × additive gene effects were larger than those of the dominance and dominance × dominance gene effects, which revealed that additive genes were more important in the contribution to chlorophyll concentrations. Broad-sense heritability estimates for color traits were 0.39, 0.611, 0.470, and 0.460 for concentrations of chlorophyll a, chlorophyll b, total chlorophyll, and RHS score, respectively. In contrast to previous findings, with the GMA analysis we believe that the genetic model of fruit color in bitter gourd is clearly a quantitative model.

著者

Nobuhiro Kotoda Satoshi Matsuo Ichiro Honda Kanako Yano Tokurou Shimizu

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-016, (Released:2016-09-27)

被引用文献数

5

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Gibberellins (GAs) are involved in many aspects of plant growth and development in higher plants. In this study, we aimed to characterize Satsuma mandarin (Citrus unshiu Marc.) GA 2-oxidase genes encoding enzymes with GA inactivation activity because the accumulation of active GAs is regulated by the balance between their synthesis and inactivation. We showed that CuGA2ox4, CuGA2ox2/3, and CuGA2ox8 were differentially expressed in various tissues in Satsuma mandarin and that these genes functioned like GA 2-oxidase genes in transgenic Arabidopsis. The expression pattern of CuGA2ox4 resembled that of CuGA20ox1, which was reported previously as a Satsuma mandarin GA 20-oxidase gene, in the reproductive tissues of the adult trees in that both genes were expressed in juice sacs in November and December and peel in December, suggesting that CuGA2ox4 and CuGA20ox1 act in concert to regulate the accumulation of active GAs in fruit at the maturing stage. On the other hand, CuGA2ox2/3 and CuGA2ox8 were more highly expressed in seeds and flower buds, respectively. Further study of GA biosynthetic genes, including GA 2-oxidase genes, would provide insight into the mechanism of flowering, fruit development, seedlessness, biennial bearing, and peel puffins of citrus such as Satsuma mandarin.

著者

Atsushi Shimada Tatsuya Kubo Shigeto Tominaga Masashi Yamamoto

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

vol.86, no.2, pp.194-199, 2017 (Released:2017-04-25)

参考文献数

27

被引用文献数

8

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The effects of temperature and light on photosynthetic, chlorophyll fluorescence characteristics under high temperature in the passion fruits ‘Summer Queen’ (P. edulis × P. edulis f. flavicarpa) and ‘Ruby Star’ (P. edulis × P. edulis f. flavicarpa) were examined. Photosynthetic rates of both cultivars markedly and linearly increased up to 300 μmol·m−2·s−1, and less markedly increased from 300 to 1500 μmol·m−2·s−1 under several light conditions. Their light saturation points were recorded at around 1200 μmol·m−2·s−1 photosynthetic photon flux densities (PPFD). Regarding the relationship between temperature and photosynthesis, the maximum value of the apparent photosynthetic rate of ‘Summer Queen’ was observed at 30°C, and it was lower at both lower and higher temperatures. In ‘Ruby Star’, on the other hand, the maximum value was observed at 20 to 30°C, and this decreased at 35 and 40°C. The gross photosynthetic rate of ‘Summer Queen’ decreased over 30°C whereas in ‘Ruby Star’, it decreased to a lesser extent. The transpiration rate of ‘Ruby Star’ was higher than that of ‘Summer Queen’ at 40°C. Dark respiration increased from 20 to 40°C in both cultivars. Concerning chlorophyll fluorescence characteristics, ‘Summer Queen’ showed high-temperature injury at 40°C and all parameters were significantly decreased at 45°C. On the other hand, Fv/Fm showed only a slight decrease at 45°C in ‘Ruby Star’. These results indicate that ‘Summer Queen’ is susceptible to heat stress and that the range of its optimal temperature for photosynthesis is lower than ‘Ruby Star’.

著者

Atsushi Imai Takeshi Kuniga Terutaka Yoshioka Keisuke Nonaka Nobuhito Mitani Hiroshi Fukamachi Naofumi Hiehata Masashi Yamamoto Takeshi 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.OKD-013, (Released:2016-09-24)

被引用文献数

12

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We analyzed the pedigree records (1995–2010) of the Kuchinotsu Citrus Breeding Program (KCBP) at the National Institute of Fruit Tree Science (NIFTS) in Japan, abbreviated as NIFTS-KCBP, to reveal the genetic background and current status of inbreeding and genetic uniformity of the parental cultivars/genotypes and their F1 breeding progenies. The founding genotypes mostly used for crossing in NIFTS-KCBP were satsuma mandarin (Citrus unshiu Marcow.), sweet orange (C. sinensis [L.] Osbeck), king mandarin (C. nobilis Lour.), clementine (C. clementina hort. ex Tanaka), mediterranean mandarin (C. deliciosa Ten.), dancy tangerine (C. tangerina hort. ex Tanaka), and ponkan (C. reticulata Blanco). The intensive use of these seven genotypes and their progenies as crossed parents has led to a high degree of inbreeding in the breeding population. Moreover, these seven genotypes have dominated about 80% of the genetic composition of the breeding population. Although further studies are needed to reveal the influence of inbreeding and genetic uniformity on agronomically important traits, these data offer useful information for the selection of cross combinations and breeding strategies in the ongoing NIFTS citrus breeding program, Japan.

著者

Mei Gao-Takai Ayako Katayama-Ikegami Shinichi Nakano Kenichi Matsuda Hino Motosugi

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-009, (Released:2016-09-17)

被引用文献数

10

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The growth and berry quality of ‘Ruby Roman’ (Vitis labruscana) grapevines grafted on two species of rootstock, ‘Kober 5BB’ [‘5BB(2×)’] (V. berlandieri × V. riparia, a semi-dwarf rootstock) and ‘Hybrid Franc’ [‘HF(2×)’] (V. rupestris × V. vinifera, a vigorous rootstock), and their colchicine-induced autotetraploids [‘5BB(4×)’ and ‘HF(4×)’] were investigated through 2 years of pot cultivation followed by 2 years of ground cultivation. During the nursery stage, the survival rate and root and shoot growth of the grafted cuttings in the two diploid rootstocks were obviously greater than in their corresponding tetraploids. During subsequent cultivation in pots and in the ground, the grapevines grafted on ‘5BB(4×)’ had less shoot growth (weight and length), shorter internode length, and in some cases smaller stem diameter than those grafted on ‘5BB(2×)’. However, in contrast with ‘5BB’, there was no significant difference in total vine growth between ‘HF(2×)’ and ‘HF(4×)’ during pot cultivation, and the total shoot length and weight in the ‘HF(4×)’ grapevine was greater than in ‘HF(2×)’ during ground cultivation in 2014. After 2 years of pot cultivation, the root growth of the ‘HF’ (diploid and tetraploid) rootstocks was more vigorous than that of the ‘5BB’ (diploid and tetraploid) rootstocks. In addition, the proportions of the thin roots (diameters <1 mm) in the two diploid rootstocks [‘5BB(2×)’ and ‘HF(2×)’] were greater than those in the two tetraploid rootstocks [‘5BB(4×)’ and ‘HF(4×)’]. In contrast, the proportions of the thick roots (diameters 1–2 mm, 2–5 mm, and >5 mm) in the two diploid rootstocks were less than those in the two tetraploid rootstocks. Furthermore, the berries of ‘Ruby Roman’ harvested from the grapevines grafted on ‘5BB(4×)’ exhibited a much deeper skin coloration than those harvested from the other grapevines.

著者

Kyeong-Seong Cheon Akira Nakatsuka Keisuke Tasaki Nobuo Kobayashi

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-025, (Released:2016-09-17)

被引用文献数

10

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Double flower form is an important trait of ornamental flower plants such as Japanese azalea because of its high visual appeal. We investigated floral phenotypes and a MADS-box C class gene to characterize floral morphology and this gene in single- and double-flowered cultivars of Japanese azaleas. Normal floral organs (sepals, petals, stamens, and carpels) were observed from each whorl of single flowers, whereas in double flowers, petaloid stamens or petals were observed from the third and fourth whorls, and there were no normal stamens or carpels in any flowers. Molecular analysis revealed that expression of the azalea AGAMOUS/PLENA (AG/PLE) homolog was lower in the inner two whorls of double flowers than in inner two whorls of single flowers, and expression of the AG/PLE homolog was higher in the double-flowered cultivars ‘Surugaman-yo’ and ‘Yodogawa’ than in other double-flowered cultivars. Moreover, sequence analysis of AG/PLE mRNA revealed deletion mutations in the coding regions of the AG/PLE homolog in ‘Surugaman-yo’ and ‘Yodogawa’. These results suggest that the double flowers of Japanese azalea cultivars are formed as the down-regulated expression and deleted sequence mutation of the azalea AG/PLE homolog.

著者

Wanita Kaewphalug Pattana Srifah Huehne Ajaraporn Sriboonlert

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-123, (Released:2016-08-25)

被引用文献数

7

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Orchids are economically valuable as cut flowers and in pot plant markets. However, a juvenility phase that is too long is the main disadvantage for commercial orchids. To understand the gene involving floral transition controls in orchids, a CONSTANS-like (COL) gene in the photoperiodic flowering pathway was isolated from Dendrobium crumenatum (pigeon orchid). The cDNA isolated has an open reading frame (ORF) of 969 bp, encoding 322 amino acids. Sequence alignment based on amino acid sequences revealed that the Dendrobium crumenatum COL (DcCOL) shared a high identity with COL isolated from other plant species including Phalaenopsis COL (85%), Oryza sativa Hd1 (70%), Erycina pusilla COL5 (EpCOL5) (66%), and Arabidopsis thaliana CO (39%). DcCOL has three conserved domains (CCT, B-box I, and B-box II domains) and is classified in group I CO/COL by phylogenetic analysis in the Arabidopsis B-box zinc finger protein family. Quantitative real-time RT-PCR demonstrated DcCOL was expressed in all stages of development and all tissue types with the highest expression in floral buds and opened flowers of mature orchids. The expression pattern under photoperiod pathway demonstrated a diurnal expression. The DcCOL was accumulated in the dark in all photoperiodic conditions, i.e., long, neutral, and short days suggesting that the regulation of DcCOL was controlled in a circadian rhythm-dependent manner. The results suggested that photoperiodism is not the main factor in D. crumenatum floral induction control. This DcCOL expression pattern coincided with the D. crumenatum flowering behavior in which the flowering occurs before dawn and lasts for only 24 h implying the function of DcCOL is related to flowering.

著者

Yoshito Sasaki Yasuo Ishii Hironobu Abe Katsuaki Mitachi Takayoshi Watanabe Tadafumi Niizato

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-132, (Released:2016-08-11)

被引用文献数

3

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To examine the translocation of radiocesium scattered by the Fukushima Daiichi nuclear power plant accident that occurred in March 2011 to the Japanese chestnut, we investigated the autoradiography and radiocesium concentration in each part of Japanese chestnuts. The Japanese chestnut fruit has a thin skin between the kernel (cotyledons) and shell; the kernel of the fruit is edible. The 137Cs concentration in each part of the fruit was found to be almost the same at about 1.0 × 104 Bq·kg−1 DW, as well as leaves. The radiocesium concentration in chestnut weevil larvae found on the fruit was approximately one-seventh of that in the kernel.

著者

Shigeki Moriya Miyuki Kunihisa Kazuma Okada Hiroshi Iwanami Hiroyoshi Iwata Mai Minamikawa Yuichi Katayose Toshimi Matsumoto Satomi Mori Harumi Sasaki Takashi Matsumoto Chikako Nishitani Shingo Terakami Toshiya Yamamoto Kazuyuki Abe

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-156, (Released:2016-07-23)

被引用文献数

21

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During apple (Malus × domestica Borkh.) storage, a loss in fruit firmness can occur. This is frequently associated with mealiness, an undesirable trait. There have been studies, such as phenotypic analyses and transcriptomics, as well as others employing a transgenic approach, focusing on this trait. Certain genetic approaches, such as quantitative trait loci (QTL) approach, however, have not been attempted. In this study, to identify and characterize QTLs controlling flesh mealiness and to investigate their application in apple breeding, we performed classical QTL mapping based on a bi-parental population and a genome-wide association study (GWAS) of mealiness. Phenotypic data for mealiness allowed us to identify two QTLs in the bi-parental family located on linkage group 10. The GWAS discovered significant marker-trait associations on chromosomes 2, 9, and 10. The MdPG1 locus, located on chromosome 10, was identified as the locus with the strongest significance by both QTL mapping and GWAS, suggesting its primary contribution to flesh mealiness. Using a tri-allelic simple sequence repeat marker, Md-PG1SSR10kd, 10 kb downstream of the MdPG1 coding sequence, we divided apple accessions into six groups based on their genotypes. Among the six groups, the Md-PG1SSR10kd genotype “2/2” had the least mealy phenotype.

著者

Miriam Valle Arizaga Oscar Fabián Villalobos Navarro Carlos Roman Castillo Martinez Esmeralda Judith Cruz Gutiérrez Humberto Antonio López Delgado Shin‑ichi Yamamoto Kazuo Watanabe Takao Niino

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-002, (Released:2016-07-16)

被引用文献数

19

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We modified the D cryo-plate protocol by paper mounting to the cryo-plate with alginate gel and shoot tips, and cryopreserved shoot tips of 13 potato genotypes (potato genetic resources in Mexico) using the revised and optimized D cryo-plate protocol. There were no significant differences in regrowth of cryopreserved shoot tips by addition of the paper mounting step to the base D cryo-plate protocol, besides a reduction in dropping shoot tips in steps during the whole procedure. Some steps of revised D cryo-plate protocol were optimized or reconfirmed, and the effect of optimizations such as cold-hardening, loading solution treatment, and post-rewarming treatment on the regeneration of shoot tips was studied. This optimized protocol was successfully applied to ‘B-71-240-2’ and 12 additional potato genotypes, resulting in 70.0%–93.3% regrowth with an average of 82.8% and stable storage for 1 year. When introducing new cryopreservation techniques, modification and optimization of the method are required to adjust to each laboratory’s circumstances. This optimized D cryo-plate method will facilitate cryobanking of potato and other plant genetic resources in Mexico for long-term preservation in a genebank.

著者

Naftali Zur Lyudmila Shlizerman Giora Ben-Ari Avi Sadka

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-147, (Released:2016-07-12)

被引用文献数

9

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Fruit splitting is a preharvest physiological disorder that occurs in many commercially important fruit species, including some citrus cultivars such as Navel oranges, Valencia oranges, and some mandarins. The phenomenon is affected by both genetic background and environmental conditions, causing heavy fruit loss in splitting-prone cultivars in some years. For instance, high levels of irrigation usually enhance splitting incidence. The phenomenon initiates at the end of the summer, toward fruit maturation, and to date, there is no way to predict splitting incidence. Here, we tested the ability of nondestructive magnetic resonance imaging (MRI), which does not alter the dimensions of the internal fruit tissues, to predict splitting incidence in ‘Nova’ mandarin fruit populations of trees subjected to two levels of irrigation (low and high). Samples, collected about two months prior to splitting appearance, were sorted by their internal tissues dimensions. Among all measured tissues, sorted navel dimensions showed the best correlation with splitting incidence. This was determined by dividing the MRI-sampled fruits into two populations, according to the actual splitting incidence, as calculated at the end of the season. Prediction of the splitting percentage in the low irrigation fruit population was than possible in the high irrigation fruit population, and vice versa. These results demonstrated the power of MRI to predict splitting probability as early as 2 months before split fruit are found. In addition to its potential practical application, the ability to predict splitting probability in a given fruit population could help elucidate the mechanism underlying the disorder.

著者

Xi Li Akira Kitajima Tsuyoshi Habu Keiko Kataoka Rihito Takisawa Tetsuya Nakazaki

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-145, (Released:2016-06-15)

被引用文献数

1

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A new method of inducing fruit abscission by incubating detached ovaries and fruits in agar medium was developed in citrus. Ovary and fruit abscission in the satsuma mandarin, ‘Kiyomi’, hyuganatsu, and ponkan during early physiological fruit drop was characterized using this method. For primary physiological fruit drop, the abscission of detached ovaries could be divided into three patterns, including an early type in hyuganatsu, a medium type in ‘Kiyomi’, and a late type in satsuma mandarin and ponkan. The cumulative abscission ratio of four species and cultivars was over 80% at 96 h after treatment. However, for secondary physiological fruit drop, the initiation of fruit abscission was earliest in hyuganatsu, and latest in satsuma mandarin. The cumulative abscission ratio was highest in ponkan at 84% and lowest in hyuganatsu at 6%. The pattern of abscission was different for primary and secondary physiological fruit drop in the four species and cultivars. High temperature promoted the abscission of detached ovaries and fruits in satsuma mandarin and ponkan. Leaf attachment suppressed fruit abscission in ‘Kiyomi’, hyuganatsu, and ponkan at 7 weeks after anthesis in 2012 and ponkan at 5 weeks after anthesis in 2013. Ovary and fruit abscission in four species and cultivars during early physiological fruit drop was characterized by incubating detached ovaries and fruits in agar medium.

著者

Yoshikuni Kitamura Yukari Kato Toshiki Yasui Hiroe Aizawa Sachiyo Ueno

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-128, (Released:2016-06-08)

被引用文献数

6

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Cut hydrangea (Hydrangea spp.) flowers are marketed at two different harvest stages, the fresh- and antique-stages. Flowers cut at the fresh-stage are harvested just after the coloring of decorative sepals is completed before flowering, and flowers cut at the antique-stage are harvested when the decorative sepals develop green and/or red colors after flowering. In almost all cultivars, an increase in the hydraulic conductance of the stomata (stomatal conductance) of the abaxial side of decorative sepals occurs during the transition from the fresh to the antique-stage. We investigated the relation between the stomatal conductance increase and the severity of the damage to decorative sepals. The degree of stomatal conductance increase regressed with the severity of the damage occurrence to the antique-stage decorative sepals before harvest. The relation between the stomatal conductance increase and vase life of antique-stage cut hydrangea flowers was also investigated. Abscisic acid (ABA)-treated antique-stage cut flowers exhibited lower stomatal conductance on the abaxial side of decorative sepals than control cut flowers. A photoperiodic change in the transpiration was observed in the control cut flowers, but not in ABA-treated cut flowers. These ABA treated cut flowers had longer vase lives than control cut flowers. To achieve minimal damage before harvest and longer vase life in the antique-stage during cut hydrangea flower production, screening for stomatal conductance non-increasing cultivars would be desirable. Since the stomatal conductance of antique-stage decorative sepals showed a highly significant correlation with fresh-stage decorative sepals, these can be used as an index in screening for stomatal conductance non-increasing cultivars.

著者

Seiji Takeda Kasumi Arakawa Takeshi Kawai

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-152, (Released:2016-06-08)

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We investigated the relationship between shoot apex morphology and anthesis time in five cultivars of Chrysanthemum morifolium flowering in summer. Fluctuating weather conditions in nature make stable production of agricultural crops difficult. The timing of floral induction and flower formation are determined by environmental factors such as day length and temperature. Although genetic analyses using model plants have provided a lot of knowledge regarding the molecular mechanism of flowering, it is difficult to apply to agricultural plants growing in the field because of the inconstant weather and lack of molecular analysis tools of many farmers. A simple morphological marker that enables farmers to predict anthesis time is useful for stable production of field-grown crops. We examined the shoot apex morphology of five Chrysanthemum morifolium cultivars weekly. Measurement of the shoot apex diameter by image analysis software showed that the shoot apex enlargement can be separated two phases, early slow-growth and later rapid-growth phases. We defined the developmental stages of the shoot apex in C. morifolium and found that the diameter of the shoot apex and developmental stages had a proportional relation. Each cultivar had a different inclination in an approximation straight line in the later rapid-growth phase. Comparison of the shoot apex morphology and weather records revealed different responses to the ambient temperature among the cultivars. The data suggest that weekly observation of the shoot apex makes it possible to characterize the cultivar and can be used to predict anthesis time. This is useful as a simple morphological marker for stable production of C. morifolium grown outdoors.

著者

Tomoki Shibuya Yuki Murakawa Koji Nishidate Manabu Nishiyama Yoshinori Kanayama

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-126, (Released:2016-06-02)

被引用文献数

6

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The flowering response to monochromatic light and flowering-related genes underlying this response need to be characterized to efficiently use light-emitting diodes for lighting culture. The flowering response to far-red light has been well studied in long-day cut flowers, but there have been few studies investigating the response to blue light. Flowering and the expression of the G. paniculata homologs of the FLOWERING LOCUS T and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 genes (GpFT, GpSOC1) were not previously promoted in Gypsophila paniculata, an important long-day cut flower, ‘Bristol Fairy’ under long-day conditions with blue light. In the present study, we found that flowering was promoted in another G. paniculata ‘Million Star’, under long-day conditions with blue light, suggesting that there is variation in G. paniculata’s flowering response to blue light. Therefore, we analyzed the expression of GpFT and GpSOC1 in the ‘Million Star’. The expression of GpFT and GpSOC1 was promoted with flowering in ‘Million Star’ under long-day conditions with blue light in contrast to ‘Bristol Fairy’. We next analyzed the G. paniculata homologs (GpFKF1, GpGI) of FLAVIN-BINDING KELCH REPEAT F-BOX 1 and GIGANTEA genes, which participate in the flowering response to blue light. GpFKF1 and GpGI amino acid sequences were well conserved; gene expression showed a diurnal rhythm with different peaks under short-day and long-day conditions, as previously observed in Arabidopsis thaliana. GpFKF1 interacted with GpGI. There were no important differences in GpFKF1 or GpGI amino acid sequences between the two cultivars. Our results suggest that variation in the flowering response to blue light is associated with GpFT and GpSOC1, rather than GpFKF1 and GpGI.