著者

Kazuma Okada Masato Wada Taku Shimizu Shigeki Moriya Kazuyuki Abe

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-101, (Released:2023-10-14)

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The Tall Spindle apple (Malus × domestica Borkh.) planting system achieves high early and sustained yields and excellent fruit quality. This system requires high-density planting (1,000–1,500 trees/acre) of highly branched (feathered) nursery trees, which increases the total cost of nursery trees purchased. To supply large quantities of highly feathered nursery trees at low prices, the nursery cycle should be shortened to one year. However, it is difficult to naturally obtain one-year-old nursery trees with sufficient feather number and length. Repeated spraying with 6-benzyladenine (BA) has been used as a conventional method to induce feather formation in apple nursery trees. We recently demonstrated that gibberellin A3 (GA3) treatment also increases the feather number on young apple trees. Here, we investigated the effects of GA3 (0, 100, 500, and 1,000 μM) and BA (0, 75, 150, and 300 mg·L−1) combinations on the production of well-feathered trees over a one-year cycle. Among the 16 GA3 and BA combinations, repeated (7 or 9 times) spraying with 1,000 μM GA3 + 300 mg·L−1 BA solution (3 or 5 mL) was the most effective method for producing highly feathered nursery trees of ‘Fuji’/JM7 over a one-year cycle. In two trials, trees treated with 1,000 μM GA3 + 300 mg·L−1 BA had 0.9–1.0-fold greater terminal shoot lengths, 1.5–1.9-fold greater feather numbers (≥ 1 cm), 2.0-fold greater feather numbers (≥ 5–< 50 cm), 1.1–1.2-fold greater feather lengths, and 0.9-fold greater trunk diameters than those treated with 300 mg·L−1 BA (conventional method). The feathers of trees treated with 1,000 μM GA3 + 300 mg·L−1 BA were predominantly 1–30 cm long (≥ 94.5%), and only few large feathers were observed. Thus, compared with the conventional method, treatment with 1,000 μM GA3 + 300 mg·L−1 BA facilitated the production of highly feathered nursery trees over a one-year cycle. It also reduced the time and labor cost required to obtain a large number of well-branched nursery trees needed for high-density plantings such as in the Tall Spindle system.

著者

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

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-010, (Released:2016-10-18)

被引用文献数

14

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

著者

Haruka Sato Natsumi Kawato Furong Li Kanto Ito Ami Shinoda Taichi Hasunuma Jiayi Liu Yasuyuki Kawaharada Chikako Nishitani Masato Wada Manabu Watanabe Sadao Komori

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-041, (Released:2023-05-31)

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Shoot regeneration experiments from growth-point-derived callus were conducted to improve apple genome editing techniques. The plant material studied was in vitro maintained shoots of ‘Fuji’. In the first step, a procedure for shoot formation from apple callus was established. After using the two earlier reported cases’ experimental procedures and media compositions, we investigated the effect of media variations in callus induction, callus multiplication, and shoot induction from the meristem. The procedure that yielded a higher shoot regeneration rate with meristem-derived callus involved shoot multiplication with 1001 medium followed by the Caboni’s callus induction medium, then without callus propagation on liquid medium, and then either Caboni’s or Saito-Suzuki’s shoot induction medium. In this experiment, axillary buds may remain as the shoot apexes were excised at 1 mm. In the next experiment, shoot apexes were excised at 0.5 mm to completely eliminate the axillary bud. Then treatment in the dark was added to the procedure to further improve shoot regeneration rates for the meristem-derived callus. Shoot multiplication medium and shoot induction medium procedures were conducted under dark conditions. This yielded the following optimal procedure: excising meristems from chlorosis shoots after 2–3 months of dark treatment in shoot multiplication medium on 1001; placing the excised meristems in Carboni’s callus induction medium in the dark for 20 days; then transferring the formed callus Saito-Suzuki’s shoot induction medium with incubation in the dark for at least 2 weeks. The shoot regeneration rates of calli treated in the dark for 6 weeks with shoot induction medium reached 68%. Relative to previous reports, this value is considered high for shoot regeneration from calli in apple cultivars.

著者

NORIYUKI FUKUNAGA MASATO WADA MAMORU HONJO YUHKO SETAISHI NAOKI HAYASHINAKA YASUHIRO TAKADA JIRO NISHIKAWA

出版者

公益財団法人 応用微生物学・分子細胞生物学研究奨励会

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.41, no.3, pp.191-205, 1995 (Released:2006-08-22)

参考文献数

35

被引用文献数

1 10

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A Gram-negative, aerobic bacterium isolated from the bottom layer of Lake Vanda, Antarctica, can grow in a synthetic medium containing biotin as a growth factor. The lipid and fatty acid compositions of the cells grown in the fatty acid-free medium were analyzed. Phosphatidylethanolamine, phosphatidylglycerol and wax esters were identified as major components of the chloroform-methanol extractable lipids. Palmitoleic and oleic acids comprised more than 90% of the total fatty acid of the lipids when the bacterium was grown at low temperature (5°C). Increasing the growth temperature induced an increase in the average fatty acyl chain length of the phospholipids and a decrease in the unsaturation degree of the fatty acyl chain of the wax esters. Increasing the NaCl concentration in the medium also induced an increase in the average fatty acyl chain length of the phospholipids. The effects of temperature and NaCl were compared further at the level of phospholipid molecular species. The sn-2 position of phosphatidylethanolamine and the sn-1 position of phosphatidylglycerol were the most sensitive sites to changes of temperature and NaCl concentration, respectively. An aerobic desaturase system was demonstrated to be the only pathway for unsaturated fatty acid synthesis in this bacterium.

著者

Chunfen Zhang Sota Sato Tatsuro Tsukuni Mamoru Sato Hatsuhiko Okada Toshiya Yamamoto Masato Wada Shogo Matsumoto Nobuyuki Yoshikawa Naozumi Mimida Kaori Takagishi Manabu Watanabe Qiufen Cao Sadao Komori

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-094, (Released:2016-04-26)

被引用文献数

3

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To select cultivars to produce doubled haploids (DHs) efficiently in an anther culture, a total of 28 apple cultivars (25 cultivars and 3 rootstock cultivars) were investigated to assess their callus formation rate, embryo formation rate, shoot formation rate from embryo and efficiency of shoot multiplication and acclimatization. The callus formation rates of ‘Red Astrachan’, ‘Kinsei’, ‘Tsugaru’, ‘Golden Delicious’ (‘GD’), ‘American Summer Pearmain’ (‘ASP’), ‘Gala’, ‘Rome Beauty’, and ‘Jonathan’ were high, but ‘JM2’ and ‘King of Tompkins’ formed no callus. Regarding the embryo formation rates, ‘ASP’, ‘Rome Beauty’, ‘M.9’, and ‘Starking Delicious’ (‘SD’) were high, but ‘GD’, ‘JM2’, ‘King of Tompkins’, ‘Ralls Janet’, and ‘Smith’s Cider’ formed no embryo. Regarding the shoot formation rate from embryos, ‘Senshu’, ‘Tsugaru’, and ‘Sansa’ showed high values, but ‘Fuji’, ‘Jonathan’, and ‘Wijcik’ did not form shoots at all. The rate of shoot formation from anthers showed a high–low order of ‘Senshu’, ‘SD’, ‘ASP’, and ‘Tsugaru’. Multiplication and acclimatization of the shoots were not easy. Many individuals died. Eventually, only ‘Senshu’ and ‘SD’ acclimatized. Therefore, cultivars that produced DHs efficiently were ‘Senshu’ and ‘SD’. The results indicated that all processes of “embryo formation”, “shoot induction”, and “shoot multiplication and acclimatization” are important for obtaining DHs in apple anther cultures.

著者

Hiroshi Iwanami Yuki Moriya-Tanaka Chikako Honda Masato Wada

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.CH-112, (Released:2015-02-21)

被引用文献数

1 2

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The thinning of flowers or fruit is an essential part of the commercial production of quality apples. Although chemical thinners are generally used in apple orchards throughout the world, hand-thinning remains essential for controlling crop load to improve fruit quality and return bloom. The objectives of this study were to investigate factors that determine the time required for hand-thinning and to elucidate cultivar-related efficiency of hand-thinning. In all cultivars, the time taken for hand-thinning per cluster became shorter after petal fall, but the degree of this decrease differed among cultivars. The time taken for hand-thinning depended on both how much and when natural abscission of fruitlets occurred. The times required for hand-thinning were very similar among clusters with four, five, or six flowers/fruitlets, which was twice as long as that required for clusters with two or three flowers/fruitlets. This means that the time required for hand-thinning clusters is critically reduced when the number of flowers/fruitlets within a cluster is three or fewer. The time required for hand-thinning clusters of axillary buds became significantly longer from bloom to 7 days after bloom, and then decreased gradually from 7 to 25 days after bloom. When the proportion of clusters with three or fewer fruitlets is 50% at 15 days after bloom, the planting area of the cultivar that a person is able to hand-thin (six hours per day) from 10 to 30 days after bloom was 24.3 a, which was 40% larger than that of a cultivar in which the proportion of clusters with three or fewer fruitlets is 50% at 30 days after bloom (17.4 a). Therefore, the introduction of cultivars in which fruit abscission occurs at an early stage and on a large scale is a solution for reducing the labor costs of hand-thinning.