著者

Takuya Morimoto Yunosuke Matsuda Ryo Sekiguchi Akihiro Itai

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-383, (Released:2022-09-30)

被引用文献数

2

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The development of intergeneric hybrids for horticultural crops has been attempted to introduce new quality and resistance traits and to enlarge the gene pool. Interspecific and intergeneric hybridization are often hindered by incompatibility reactions occurring at various stages of hybridization, from early pollination to initial growth, and the reproductive stages of the progeny. In this study, we investigated intergeneric and interspecific cross-compatibility among six species in the tribe Maleae (Rosaceae), namely, Pyrus communis (European pear), P. pyrifolia (Japanese pear), Malus × domestica (apple), Eriobotrya japonica (loquat), Cydonia oblonga (quince), and Pseudocydonia sinensis (Chinese quince). In vivo pollen tube growth tests showed the presence of a postmating, prezygotic barrier in many cross-combinations, in which cross-compatibility was regulated by both genetic distance and crossing direction. Strong hybridization barriers were observed in pollen tube growth and fruit setting when intergeneric hybridization was performed with E. japonica, a species phylogenetically distant from the others studied. Different compatibility reactions in reciprocal crosses were observed in some intergeneric hybridizations; C. oblonga as a pollen donor was incompatible with P. sinensis, whereas the reciprocal cross was compatible, resulting in the development of hybrid seedlings. Furthermore, the pollen tube growth rate differed among Pyrus species when pollinated on the apple pistils, suggesting divergence of cross-compatibility response in a specific linage. Factors affecting intergeneric hybridization are discussed with reference to the genetic distance between species and morphological characteristics such as pistil length. Our comprehensive assessment of intergeneric cross-compatibility will help provide a way to overcome crossing barriers and develop new hybrid crops in the tribe Maleae.

著者

Akiko Ito Daisuke Sakamoto Akihiro Itai Takaaki Nishijima Naomi Oyama-Okubo Yuri Nakamura Takaya Moriguchi Ikuko Nakajima

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-107, (Released:2015-12-17)

被引用文献数

10

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In order to promote increases in the size of ‘Kosui’ Japanese pear [Pyrus pyrifolia (Burm.) Nakai] fruit by plant growth regulators, we applied gibberellin (GA)3+4 paste [2.7% (w/w), A3:A4 = 90:10] in combination with prohexadione-calcium [1%, PCa; BAS-125 (3-oxido-4-propionyl-5-oxo-3-cyclohexene-carboxylate)], an inhibitor of GA 2β-hydroxylation that catabolizes active GA into an inactive form, to fruit pedicels at approximately 30 days after full bloom. GA3+4+PCa treatment advanced fruit growth only in the early stages, but fruit weight did not show any significant differences between the untreated control and GA3+4+PCa-treated fruits at harvest. In contrast, when GA4+7 [2.7% (w/w), A4:A7 = 66:34] was applied, the fruit weight at harvest was greater than that of untreated fruit. Moreover, GA4+7 treatment in combination with PCa resulted in an even higher fruit weight at harvest. The GA4 concentration in fruit flesh was not affected by GA3+4 application at 1 week after the treatment (WAT) either with or without PCa, but GA4 levels increased with GA4+7+PCa treatment, resulting in a significant increase in fruit weight at harvest. A single GA4+7 application almost doubled the GA4 concentration compared with the untreated control, but the difference was not significant. These results indicate that fruit weight at harvest was greater when the GA4 concentration was higher in the fruit flesh at 1 WAT. The higher concentration of GA4 in the GA4+7+PCa-treated fruit compared with the GA4+7 treatment alone may be attributed to the function of PCa that acts to prevent the inactivation of GA4 to GA34 by inhibiting 2β-hydroxylation.