著者

Miyako Kato Hitoshi Watanabe Yoichiro Hoshino

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.39, no.2, pp.85-92, 2022-06-25 (Released:2022-06-25)

参考文献数

37

被引用文献数

2

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Pollen tube growth is essential for the fertilization process in angiosperms. When pollen grains arrive on the stigma, they germinate, and the pollen tubes elongate through the styles of the pistils to deliver sperm cells into the ovules to produce the seeds. The relationship between the growth rate and style length remains unclear. In previous studies, we developed a liquid pollen germination medium for observing pollen tube growth. In this study, using this medium, we examined the pollen tube growth ability in Petunia axillaris subsp. axillaris, P. axillaris subsp. parodii, P. integrifolia, and P. occidentalis, which have different style lengths. Petunia occidentalis had the longest pollen tubes after 6 h of culture but had a relatively shorter style. Conversely, the pollination experiments revealed that P. axillaris subsp. parodii, which had the longest style, produced the longest pollen tubes in vivo. The results revealed no clear relationship between the style lengths and the growth rate of pollen tubes in vitro. Interspecific pollinations indicated that the styles affected pollen tube growth. We concluded that, in vitro, the pollen tubes grow without being affected by the styles, whereas, in vivo, the styles significantly affected pollen tube growth. Furthermore, interspecific pollination experiments implied that the pollen tube growth tended to be suppressed in the styles of self-incompatibility species. Finally, we discussed the pollen tube growth ability in relation to style lengths.

著者

Yoichiro Hoshino Noriko Kanematsu Masahiro Mii

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.68, no.3, pp.360-366, 2018 (Released:2018-08-02)

参考文献数

26

被引用文献数

1 2

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Lilies (Lilium spp.) are one of the most important floricultural crops. As most lily cultivars have originated from interspecific hybridization, they usually have complex genome composition and occasionally fail to develop normal gametes. Further improvement of lily cultivars by sexual crossing requires evaluation of gamete development and subsequent male and female fertility. Although male fertility is easily evaluated through microscopic observation after staining or by pollen culture for germination, evaluation of female fertility is difficult, because gametes develop inside an ovule within an ovary. Lilium species have the Fritillaria type of embryo sac, which, at maturity, consists of a haploid egg apparatus, including one haploid egg cell and two haploid synergids, two polar nuclei (one haploid nucleus and one triploid nucleus) and three triploid antipodal cells. Compared to the Polygonum type of embryo sac, composition of the embryo in the Fritillaria type of embryo sac is complex. We developed an efficient microscopic observation technique for ovules using the clearing procedure, which allowed us to categorize abnormal patterns of female gametes and to elucidate the frequency of abnormal female gamete development. The relationship among normal embryo sac, pollen stainability and seed formation in lily cultivars is discussed.

著者

Issei Asakura Yoichiro Hoshino

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-163, (Released:2018-05-22)

被引用文献数

3

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Actinidia kolomikta (Maxim. & Rupr.) Maxim., a wild kiwifruit relative native to East Asia, has several desirable characteristics, such as strong cold tolerance, precocity, and high levels of vitamin C, and has therefore attracted horticultural interest. In this study, the interspecific cross compatibility of the diploid Actinidia kolomikta with one cultivated species [A. deliciosa (A. Chev.) C. F. Liang & A. R. Ferguson], three native Actinidia species [A. arguta (Siebold & Zucc.) Planch. ex Miq., A. polygama (Siebold & Zucc.) Maxim., and A. rufa (Siebold & Zucc.) Planch. ex Miq.], and one endemic variety [A. arguta (Siebold & Zucc.) Planch. ex Miq. var. hypoleuca (Nakai) Kitam.], was evaluated to see if interspecific hybridization using A. kolomikta could improve edible Actinidia crop breeding programs. There was no fruit setting two weeks after anthesis in the tested cross combinations when A. kolomikta was the male parent. In contrast, all five crosses using A. kolomikta as the female parent produced 100% fruit setting two months after pollination. The crosses with different ploidy levels such as combinations between diploid A. kolomikta and hexaploid A. deliciosa, or diploid A. kolomikta and tetraploid A. arguta, produced a few viable seeds. In contrast, the crosses with diploid species such as A. arguta var. hypoleuca, A. polygama, and A. rufa, produced many viable seeds and seedlings. From these results, the cross compatibilities of A. kolomikta with the other tested species were categorized as follows: no fruit setting (A. arguta × A. kolomikta and A. polygama × A. kolomikta); fruit setting with few viable seeds (A. kolomikta × A. arguta and A. kolomikta × A. deliciosa); and normal fruit setting with viable seeds (A. kolomikta × A. arguta var. hypoleuca, A. kolomikta × A. polygama, and A. kolomikta × A. rufa). These results could be a basis for future edible Actinidia crop breeding programs using A. kolomikta and interspecific hybridization.