著者

Rihito Takisawa Takayuki Maruyama Tetsuya Nakazaki Keiko Kataoka Hiroki Saito Sota Koeda Tsukasa Nunome Hiroyuki Fukuoka Akira Kitajima

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-042, (Released:2017-03-03)

被引用文献数

20

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Parthenocarpy is a trait where fruit set and growth are triggered without pollination and fertilization. In the tomato (Solanum lycopersicum L.), this trait is considered attractive as it reduces the cost and labor requirements for fruit setting. In this study, we investigated the inheritance of parthenocarpy in ‘MPK-1’—a parthenocarpic tomato cultivar derived from a cross between a variant from a self-fertilization posterity of ‘Severianin’, which exhibited strong parthenocarpy and a non-parthenocarpic cultivar. It was reported that ‘MPK-1’ contains a pat-2 gene because ‘Severianin’ which has a pat-2 gene is its only parthenocarpic ancestor. However, we found that parthenocarpy in ‘MPK-1’ is controlled by a novel parthenocarpic gene, not pat-2. This novel gene, which was designated as Pat-k, is semi-dominant and located on chromosome 1. We also showed that the size of the parthenocarpic fruit of ‘MPK-1’ is similar to that of the pollinated fruit at maturity. Thus, ‘MPK-1’ may be used as a new parthenocarpic resource for breeding.

著者

Xi Li Akira Kitajima 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.OKD-054, (Released:2017-01-25)

被引用文献数

3

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Histological investigations of the fruit abscission zone and morphological changes in abscission zone cells in ponkan (C. reticulata Blanco), hyuganatsu (C. tamurana hort. ex Tanaka), ‘Kiyomi’ (C. unshiu × C. sinensis (L.) Osbeck), and satsuma mandarin (Citrus unshiu Marcow.) were conducted using detached fruits incubated in agar medium under 25°C, 4 weeks after anthesis during secondary physiological fruit drop. In the 96 h after the fruit abscission induction by detaching the fruits, the cumulative abscission ratio was 100% in ponkan, 22% in ‘Kiyomi’, and below 10% in hyuganatsu and satsuma mandarin. Fruit abscission began at 36 h in ponkan and ‘Kiyomi’, at 54 h in satsuma mandarin, and at 60 h in hyuganatsu after the fruit detachment. The fruit abscission zone was located on the connected part between the fruit and the disc in ponkan and hyuganatsu on the disc tissue in satsuma mandarin and ‘Kiyomi’. During the fruit abscission process, no abscission layer was observed at the abscission zone in these species and cultivars. Morphological changes in the abscission zone cells were determined by scoring cell changes (a score from 0 to 4) at five positions of the abscission zone. In ponkan, the morphological changes in the abscission zone cells, which began 30 h after fruit abscission induction, were synchronized in a symmetrical position in the abscission zone. The changes in ‘Kiyomi’ began at 30 h, and they consisted of a one sided collapse of the symmetrical position of the abscission zone. The changes in satsuma mandarin were similar to those in ‘Kiyomi’. This implies that the different patterns of morphological changes in the abscission zone cells in ponkan, ‘Kiyomi’, and satsuma mandarin depend on the different locations of their abscission zones. Overall, the results suggest that the cue for fruit abscission in early abscised fruit occurs until 30 h after blocking the carbohydrate translocation to the fruit under 25°C.

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

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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

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

Sota Koeda Kosuke Sato Kenichi Tomi Yoshiyuki Tanaka Rihito Takisawa Munetaka Hosokawa Motoaki Doi Tetsuya Nakazaki Akira Kitajima

出版者

園芸学会

雑誌

Journal of the Japanese Society for Horticultural Science (ISSN:18823351)

巻号頁・発行日

pp.CH-105, (Released:2014-05-10)

被引用文献数

3 19

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‘No.80’ (Capsicum chinense) from the Caribbean is a valuable genetic source from the aspect of its non-pungent and highly aromatic traits. In the present study, the non-pungency, volatile components, and phylogenetic origin of ‘No.80’ were analyzed with another C. chinense cultivar, ‘No.2’ from Brazil, which is also non-pungent but less aromatic. Expressions and deduced amino acid sequences of acyltransferase (Pun1) of ‘No.80’ and ‘No.2’ were normal compared with a pungent cultivar, ‘Habanero’. Insertions of 7-bp and 8-bp resulting in frameshift mutations were found in the coding regions of putative aminotransferase (p-AMT) of ‘No.80’ and ‘No.2’, respectively. Co-segregation of these insertions with the non-pungent phenotypes in F1 and F2 populations obtained from crossing ‘No.80’ or ‘No.2’ with ‘Habanero’ suggested that non-pungency in these cultivars arose from genetic mutations of p-AMT that occurred independently. Moreover, molecular phylogenetic analysis suggested that ‘No.80’, a close relative of ‘No.2’, originates from capsicums migrated from the South American mainland. In addition to pungency, we assessed the volatile components of the highly aromatic ‘No.80’, the less aromatic ‘No.2’, and their F1 hybrid using gas chromatography. ‘No.80’ contained higher levels of aroma-contributing volatiles than ‘No.2’, which correlated with the stronger and weaker aromas of two cultivars. Further, the fruit of F1 progenies emitted a number of volatile compounds between or higher than their corresponding parents. Based on these results, the approaches for breeding highly aromatic non-pungent cultivars are discussed.