著者

Akira Yamazaki Ao Takezawa Kazusa Nishimura Ko Motoki Kyoka Nagasaka Ryohei Nakano Tetsuya Nakazaki Munetaka Hosokawa

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-094, (Released:2023-10-17)

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Chili pepper is cultivated in the absence of fruit-promoting treatments or insect pollinators. The fertilization ability of both males and females, as well as natural self-pollination ability under high temperatures, are necessary for autonomous set fruit under high temperatures. The reproductive traits related to autonomous self-pollination ability and fertilization ability of both males and females after pollination under control (CK) and high temperature (HT) treatments were investigated in this study. ‘Takanotsume’ (TK) showed a significantly higher percentage of autonomous fruit set than ‘Peruvian Purple’ (PP) in both CK and HT treatments, suggesting that TK has a strong autonomous fruit set regardless of temperature. On the other hand, the percentage of autonomous fruit set of PP was 0% in the HT treatment, while autonomous fruit set was observed in the CK treatment. Therefore, TK had autonomous fruit set ability even at high temperatures when PP did not have any. TK had more pollen on the stigma than PP, suggesting that TK has a higher ability for autonomous self-pollination. Flower morphology was not considered a factor in the autonomous self-pollination of TK. In contrast, TK tended to release more pollen than PP. One factor that can support autonomous self-pollination is pollen dispersion. A significant difference was observed in the fruit set rate during artificial pollination between the treatments (CK and HT) of the pollen parent and the cultivars (TK and PP) of the seed parent. In fact, female fertility in TK was higher than that in PP, regardless of the temperature condition. Almost no fruit set of PP was observed via autonomous self-pollination in the HT treatment, but fruits were set by artificial pollination using both the pollen and pistil of PP in the HT treatment. This result is consistent with the finding that PP exhibits decreased autonomous self-pollination at high temperatures. The higher autonomous fruit-set ability of TK than PP under high temperatures may be attributed not only to superior female fertility, but also to its autonomous self-pollination ability under high temperatures. Therefore, pollen dispersal ability under high temperatures was considered a key factor for autonomous fruit-set.

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

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

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.