title: Chlorophenoxyacetic acid and chloropyridylphenylurea accelerate translocation of photoassimilates to parthenocarpic and seeded fruits of muskmelon (Cucumis melo).
abstract: We compared the effect of p-chlorophenoxyacetic acid (p-CPA) and 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU) on parthenocarpic and seeded muskmelon (Cucumis melo) fruits in regards to fruit development and the transport of photoassimilates from leaves exposed to ¹⁴CO₂ to the developing fruits. Ten days after anthesis (DAA), the fresh weight, total ¹⁴C-radioactivity and contents of ¹⁴C-sucrose and ¹⁴C-fructose were higher in the CPPU-induced parthenocarpic fruits than in seeded fruits. However, at 35 DAA, fresh weight and sucrose content in mesocarp, placenta and empty seeds of the parthenocarpic fruits were lower than in seeded fruits. Also, total ¹⁴C-radioactivity and ¹⁴C-sugar content of the parthenocarpic fruits were lower as well as the translocation rate of ¹⁴C-photoassimilates into these fruits. Application of p-CPA to the parthenocarpic fruits at 10 and 25 DAA increased fresh weight and sugar content. Moreover, these treatments elevated the total ¹⁴C-radioactivity, ¹⁴C-sucrose content and the translocation rate of ¹⁴C-photoassimilates. The ¹⁴C-radioactivity along the translocation pathway from leaf to petiole, stem, lateral shoot and peduncle showed a declining pattern but dramatically increased again in the fruits. These results suggest that the fruit's sink strength was regulated by the seed and enhanced by the application of p-CPA.
authors.affiliation: Fruit Processing Research Center, AOHATA Corporation, Takehara, Hiroshima 729-2392, Japan.
authors.forename: Xin-Xian
authors.initials: XX
authors.lastname: Li
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Kobayashi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ikeura
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Hayata
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D050260:Carbohydrate Metabolism; D002247:Carbon Isotopes / Q000032:analysis; D028463:Cucumis melo / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D003583:Cytokinins / Q000494:pharmacology*; D005632:Fructose / Q000032:analysis; D005638:Fruit / Q000187:drug effects*; D010671:Phenylurea Compounds / Q000494:pharmacology*; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D054817:Pollination; D011725:Pyridines / Q000494:pharmacology*; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D013395:Sucrose / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D003583:Cytokinins; D010671:Phenylurea Compounds; D011725:Pyridines; D015084:2,4-Dichlorophenoxyacetic Acid; D005632:Fructose; C007017:4-chlorophenoxyacetic acid; D013395:Sucrose; C116093:N-(2-chloro-4-pyridyl)-N'-phenylurea