著者

Katsuya Ohkawa Natsumi Ogata Akane Shibasaki Takahisa Tanaka Ryo Itabashi Chie Kouno Takanori Saito Hitoshi Ohara Satoru Kondo

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-064, (Released:2023-08-11)

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To elucidate the inhibitory effect of ethephon on the occurrence of water-soaked disorder in Japanese pear ‘Akizuki’ (Pyrus pyrifolia Nakai) fruit, we sprayed fruits with 100 mg·L−1 ethephon solution approximately 120 DAFB in the 2012, 2014, 2015, 2016, and 2017 seasons. Ethephon treatment reduced the incidence and degree of water-soaked disorder at commercial harvest time. There was no significant difference in fruit size or soluble solids content between the ethephon-treated fruits and the control fruits, except for fruit size in the 2012 season. During the nine-day storage period after harvest, water-soaked disorder did not develop in either the ethephon-treated fruits or the control fruits. In addition, flesh firmness and soluble solids content did not differ between the ethephon-treated fruits and the control fruits during the storage period. Ethylene production increased sharply in the ethephon-treated fruits a few days after the ethephon treatment, in contrast to the control fruits. Sucrose content in the ethephon-treated fruits was higher than that in the control fruits on day 10 after treatment. Sorbitol content in the ethephon-treated fruits was lower than that in the control fruits on days 10 and 20 after treatment. Water-soluble, Na2CO3-soluble, and total pectin contents were not affected by the ethephon treatment. Hemicellulose, cellulose, and starch contents in the ethephon-treated fruits decreased earlier than those in the control fruits. Sucrose content was lower, but sorbitol and glucose contents were higher, in water-soaked tissue than in sound tissue. These results suggest that ethephon treatment rapidly induces changes in the contents of fruit’s internal components and accelerates fruit maturation, thereby alleviating factors that cause water-soaked disorder in ‘Akizuki’.

著者

Akane Shibasaki Tomohito Shimada Satoru Kondo Hitoshi Ohara Katsuya Ohkawa

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-030, (Released:2023-03-11)

被引用文献数

2

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Artificial pollination is essential in pears (Pyrus spp.) for stable fruit set and the production of high-quality fruit. Low temperatures in the early spring before bud flowering can damage pear pollen and pose a special risk to pollen production for artificial pollination. In this study, we sought to identify, in pears, the flower bud stage most susceptible to low-temperature pollen damage, observe anther development abnormalities, compare pollen sensitivities among seven pear cultivars, and evaluate the pollen cold injury inhibition efficacy of a coffee extract treatment for flower buds. The most cold-sensitive flower bud stage for the Japanese pear ‘Kosui’ pollen was the scale-separation stage, with pollen in that stage ranging from the pollen mother cell to the tetrad stage. In the ‘Kosui’ flower bud treated at −3°C over 10 h, the typical cold-induced anther development abnormalities were tapetum hypertrophy, cell debris, and anther locule shrinkage. Flower buds at the scale-separation stage of seven pear cultivars were treated with low temperatures in a model based on daily temperature changes during the winter season in Saitama, Japan, to reach daily minimum temperatures of 0, −1, −2, −3, −4, −5, and −6°C. The pollen germination rates of ‘Hosui’ were unaffected by low-temperature treatments between 0 and −6°C. Overall ‘Hosui’ showed the least reduction in pollen germination rate than the other cultivars evaluated. Our results strongly suggest that ‘Hosui’ is the most tolerant to low temperatures among the tested cultivars. In the laboratory environment, the application of a coffee extract before cold treatment delayed flower bud freezing and preserved pollen germination. These results are helpful in selecting varieties and treatments for the prevention of cold injury in pear pollen production.

著者

Sirinan Suktawee Masahiro Shishido Shanshan Wang Takanori Saito Katsuya Okawa Hitoshi Ohara Hataitip Nimitkeatkai Hiromi Ikeura Satoru Kondo

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-001, (Released:2018-08-18)

被引用文献数

7

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The effects of the jasmonic acid derivative n-propyl dihydrojasmonate (PDJ) on ethylene signal transduction and endogenous jasmonic acid (JA) in apples infected with Botrytis cinerea (gray mold) were investigated. Apples were dipped into 400 μM PDJ solution and then inoculated with B. cinerea. The fruit were stored at 25°C and 95% relative humidity for 16 days after PDJ treatment. The inoculation without PDJ application (PDJ− Ino+) showed larger B. cinerea lesion diameters compared to the PDJ application with inoculation (PDJ+ Ino+) and the untreated controls. In contrast, the PDJ+ Ino+ group showed a higher ethylene production rate, higher 1-aminocyclo-propane-1-carboxylic acid (ACC) concentration, and greater expressions of ethylene-related genes [MdACS1 (ACC synthase), MdACO1 (ACC oxidase), MdETR1 (Ethylene receptor 1), MdERS1 (Ethylene response sensor 1), and MdCTR1 (Constitutive triple response 1)], and endogenous JA, MdAOS1 (Allene oxide synthase 1) gene. However, the abscisic acid concentrations were decreased in the PDJ+ Ino+ group. The results suggest that PDJ application induces ethylene production through ethylene-related genes and endogenous JA, resulting in B. cinerea infection inhibition.

著者

近藤 悟 Satoru Kondo

雑誌

人文論究 (ISSN:02866773)

巻号頁・発行日

vol.51, no.4, pp.201-213, 2002-02-10