Effects of exogenous application of CPPU, NAA and GA4+7 on parthenocarpy and fruit quality in cucumber (Cucumis sativus L.)

Abstract

In protected vegetable fields, plant growth regulators are often used to improve cucumber fruit growth. However, the effects of plant growth regulators on the appearance and nutritional quality of cucumber (Cucumis sativus L.) remain largely unknown. In the present study, 100 mg/L N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU), naphthaleneacetic acid (NAA) or gibberellin A4+A7 (GA₄₊₇) was applied to the female cucumber flowers 1 day before anthesis and at anthesis. The CPPU, NAA and GA₄₊₇ treatments resulted in parthenocarpic fruits with similar weights, sizes and shapes as the pollinated fruits. NAA treatment did not affect the appearance and nutritional characteristics of cucumber at harvest and after storage. CPPU treatment increased the flesh firmness at harvest but decreased phenolic acid and vitamin C contents after storage. GA₄₊₇ treatment decreased the flesh firmness but increased total flavonoids and protein content after storage.

Keywords: CPPU; Cucumber; Gibberellic acid; Gibberellin A4+A7 (PubChem CID: 165669); N-(2-chloro-4-pyridyl)-N′-phenylurea (PubChem CID: 93379); Naphthaleneacetic acid; Naphthaleneacetic acid (PubChem CID: 6862); Parthenocarpy.