Elsevier

Scientia Horticulturae

Volume 209, 19 September 2016, Pages 255-260
Scientia Horticulturae

Effects of pre-harvest application of ethephon or abscisic acid on ‘Kohi’ kiwifruit (Actinidia chinensis) ripening on the vine

https://doi.org/10.1016/j.scienta.2016.06.026Get rights and content

Highlights

  • The effects of ethephon, abscisic acid (ABA), and nordihydroguaiaretic acid (NDGA) application on the ripening of pre-harvest ‘Kohi’ kiwifruit (Actinidia chinensis) were studied.

  • Only 4% fruit dropped to 9 DAT when fruit reached an edible condition, although it is significantly higher than other treatments.

  • ‘Kohi’ kiwifruit may be ripened by on-vine ethephon application at 9 DAT, thus obviating ripening treatment after harvest.

Abstract

The effects of ethephon, abscisic acid (ABA), and nordihydroguaiaretic acid (NDGA) application on the ripening of pre-harvest ‘Kohi’ kiwifruit (Actinidia chinensis) were studied. The fruits were treated on-vine at 155 days after full bloom (DAFB) (mature stage) with 250 μL/L ethephon, 100 μmol ABA, or 100 μmol NDGA. The fruits were sampled at 0, 3, 6, 9, and 12 days after treatment (DAT), and the following were analyzed at each time point: ethylene production, 1-aminocyclopropane-1-carboxylate (ACC) and ABA concentrations, ACC synthase (ACS) and ACC oxidase (ACO) activities, volatile compounds (n-hexanal and (E)-2-hexexnal), and the expressions of AcACS1, AcACO1, and 9-cis-epoxycarotenoid dioxygenase 1 (AcNCED1) genes. ABA concentrations and AcNCED1 gene expression increased in ABA-treated fruit. Malic acid concentrations and fruit firmness decreased in ethephon-treated fruit, but soluble solids concentrations (SSC), ethylene biosynthesis, and both AcACS1 and AcACO1 gene expressions increased. The accumulated fruit drop rate in ethephon-treated fruit was 4% at the edible stage at 9 DAT. Moreover, the production of n-hexanal and (E)-2-hexexnal decreased in ethephon-treated fruit. These results suggest that ‘Kohi’ kiwifruit may be ripened by on-vine ethephon application at 9 DAT, thus obviating ripening treatment after harvest.

Introduction

Kiwifruit is classified as a climacteric fruit because it ripens in response to exogenous ethylene, and its ripening is characterized by a period of autocatalytic ethylene production (Park and Kim, 1995). The ripening of kiwifruit appears to be different from that of other typical climacteric fruit because fruit produces little ethylene while on the vine (Patterson et al., 2003). However, kiwifruit ripens with ethylene treatment after harvesting (Sfakiotakis et al., 1997, Mworia et al., 2010). There are two commercially important species of kiwifruit: Actinidia deliciosa and Actinidia chinensis. A. deliciosa, including cultivars such as ‘Hayward’, is widely known for its large fruit size, green flesh, and long storage life (Thompson et al., 2000). A. chinensis, including such cultivars as ‘Hort 16A’, ‘Sanuki Gold’, and ‘Kohi’, has yellow flesh, high soluble solids and low organic acid concentrations, but a short storage life (Xu et al., 1998, Xu et al., 2000). In general, A. chinensis produces more ethylene than A. deliciosa (Asiche et al., 2016). These results may hint that the fruit of A. chinensis could ripen more easily than that of A. deliciosa and also, the fruit has a shorter storage and shelf life than that of A. deliciosa. Ethylene is a kind of plant hormone that is involved in fruit ripening in many plants (Guo and Ecker, 2004). Ethephon has been applied to both A. deliciosa and A. chinensis commercially to accelerate ripening after harvest (Park et al., 2006, Mworia et al., 2010, Zhang et al., 2012, Pranamornkith et al., 2012). If kiwifruit can be ripened on the vine, the fruit may be more marketable.

ABA concentrations are very low in unripe climacteric fruit such as tomato (Solanum lycopersicum) (Zhang et al., 2009a), peach (Pruns persica) (Zhang et al., 2009b), and avocado (Persea americana) (Chernys and Zeevaar, 2000) but increase during fruit ripening. Therefore, ABA may also play an important role in regulating fruit ripening. The previous research suggested that ABA stimulated the processes of fruit ripening and promoted ethylene biosynthesis in climacteric fruits such as banana (Musa sapientum L.) (Jiang et al., 2000) and apple (Malus domestica) (Kongsuwan et al., 2012). However, the interaction between ABA and ethylene biosynthesis in ‘Kohi’ kiwifruit on the vine is unclear. Nordihydroguaiaretic acid (NDGA) is an ideal inhibitor of NCED enzyme and blocks ABA biosynthesis (Zhang et al., 2009a). NDGA was treated to clarify the roles of ABA in kiwifruit ripening. In this study, the possibility of the fruit ripening on the vine and the effects of ethylene or ABA on the ripening of ‘Kohi’ kiwifruit on the vine were investigated.

Section snippets

Plant material

Three-year-old ‘Kohi’ kiwifruit (A. chinensis) vines top-grafted on ‘Hayward’ kiwifruit (A. deliciosa) vines at a Chiba University field, located at 35°N, Lat. 140°E, and elevation 37 m, were used in the experiment. Four hundred fruits were randomly divided into four groups at 155 DAFB (mature stage). The mature stage of kiwifruit has 95% black seeds and the color change of outer pericarp commences (Richardson et al., 2011). In the first group, the fruits were dipped into a 250 μL/L ethephon

Fruit firmness and concentrations of soluble solids and malic acid

Fruit firmness in ethephon-treated fruit decreased significantly at 3 DAT, and the fruit became edible at 9 DAT on the vine (Fig. 1). The soluble solids concentration (SSC) in ethephon-treated fruit increased significantly at 3 DAT, and the malic acid concentration decreased at 6 DAT. The SSC was higher in ABA-treated fruit than in the untreated control at 12 DAT. The fruit drop rate in the ethephon-treated fruit was 4% when the fruit reached edible condition at 9 DAT and was significantly

Discussion

Kiwifruit contains little endogenous ethylene at harvest but is highly sensitive to exogenous ethylene after harvest (Schroder and Atkinson, 2006). Ethylene application promoted fruit softening in kiwifruit after harvest (Ritenour et al., 1999). In addition, the results of our study indicated that ethephon treatment can increase SSC in ‘Kohi’ kiwifruit on the vine. Together, these results suggest that the ethylene signal can enhance both the conversion from starch to sugars and the reduction of

References (40)

  • S. Wang et al.

    Jasmonate application influences endogenous abscisic acid, jasmonic acid and aroma volatiles in grapes infected by a pathogen (Glomerella cingulata)

    Sci. Hortic.

    (2015)
  • S. Zaharah et al.

    Mode of action of abscisic acid in triggering ethylene biosynthesis and softening during ripening in mango fruit

    Postharvest Biol. Technol.

    (2013)
  • M. Zhang et al.

    Cloning and functional analysis of 9-cis-epoxycarotenoid dioxygenase (NCED) genes encoding a key enzyme during abscisic acid biosynthesis from peach and grape fruits

    J. Plant Physiol.

    (2009)
  • L. Zhang et al.

    Effects of ethephon on physiochemical and quality properties of kiwifruit during ripening

    Postharvest Biol. Technol.

    (2012)
  • W.O. Asiche et al.

    Extension of shelf-life by limited duration of propylene and 1-MCP treatments in three kiwifruit cultivars

    J. Jpn. Soc. Hortic. Sci.

    (2016)
  • J.P. Bartley et al.

    Production of volatile compounds in ripening kiwifruit (Actinidia chinensis)

    J. Agric. Food Chem.

    (1989)
  • J.T. Chernys et al.

    Characterization of the 9-cis-epoxycarotenoid dioxygenase gene family and the regulation of abscisic acid biosynthesis in avocado

    J. Plant Physiol.

    (2000)
  • J.G. Dong et al.

    Cloning of a cDNA encoding 1-aminocyclopropane-1-carboxylate synthase and expression of its mRNA in ripening apple fruit

    Planta

    (1991)
  • D.C. Henderson et al.

    CKC: isolation of nucleic acids from a diversity of plants using CTAB and silica columns

    Mol. Biotechnol.

    (2013)
  • S. Huang et al.

    Draft genome of the kiwifruit Actinidia chinensis

    Nat. Commun.

    (2013)
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