Pattern and Trigger of Fruit Self-thinning in Japanese Pears

• Nakamura-Yamaguchi Ayako

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization) Kihara Institute for Biological Research, Yokohama City University

• Kitahata Nobutaka

  RIKEN Center for Sustainable Resource Science Graduate School of Agricultural and Life Science, The University of Tokyo

• Nishitani Chikako

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization)

• Takada Norio

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization)

• Terakami Shingo

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization)

• Sawamura Yutaka

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization)

• Matsuyama Tomoki

  RIKEN Cluster for Pioneering Research

• Asami Tadao

  Graduate School of Agricultural and Life Science, The University of Tokyo

• Nakano Takeshi

  RIKEN Center for Sustainable Resource Science Graduate School of Biostudies, Kyoto University

• Saito Toshihiro

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization)

• Yamamoto Toshiya

  Institute of Fruit Tree and Tea Science, NARO (National Agriculture and Food Research Organization)

Abstract

In fruit production, fruit thinning is required to maximize fruit quality and to protect the mother trees. However, thinning is troublesome and laborious work. Fruit self-thinning is the spontaneous elimination of pollinated flowers or fruits within a week to a month after pollination. Since the fruit self-thinning trait has the potential to improve fruit trees, a number of studies using fruit crops such as apple, orange, and tomato have been conducted to clarify the underlying mechanisms. The Japanese pear accession ‘Chojuro’ and its descendants ‘Niitaka’, 162-29, and ‘Akiakari’ have this trait. To identify the pattern and trigger of thinning in the accessions, we pollinated all flowers on the flowering day and recorded the numbers of retained and abscised fruits and the order of flowering in the cluster. The number of retained flowers/fruits in a cluster was widely variable in ‘Chojuro’ and ‘Niitaka’, but was uniform at 3 to 6 fruits per cluster in 162-29 and ‘Akiakari’. In 162-29 and ‘Akiakari’, the earlier the flower opened, the more likely it was to be retained in the cluster, similar to previous observations in apple. In contrast, ‘Chojuro’ and ‘Niitaka’ fruits abscised independently of the flowering order. Therefore, the pattern of fruit self-thinning in pear depends on the accession. To identify the trigger for fruit self-thinning, we analyzed changes in the levels of endogenous auxins and abscisic acid. The results implicate auxin and, to a lesser extent, abscisic acid in fruit self-thinning. Retained fruits showed temperature-dependent transient auxin accumulation, which may trigger self-thinning in pear.

Journal

• The Horticulture Journal

  The Horticulture Journal 89 (4), 367-374, 2020

  The Japanese Society for Horticultural Science

Keywords

• auxin
• ‘Chojuro’
• <i>Pyrus pyrifolia</i>

Details

• CRID: 1390848250130822272
• NII Article ID: 130007879274
• NII Book ID: AA12708073
• DOI: 10.2503/hortj.utd-177
• ISSN: 21890110
• ISSN: 21890102
• NDL BIB ID: 030514979
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I030514979
• Web Site: https://www.jstage.jst.go.jp/article/hortj/89/4/89_UTD-177/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed