ナフトキノン誘導体, 2-benzimidoy1-3-hydroxy-1,4-naphthoquinone がトマトの生育に及ぼす影響 (第1報)

Abstract

1) Parthenocarpy of dwarf tomato (cv. Miniature) induced by synthetic naphthoquinone derivatives was investigated. 3-Phenyl-4, 9-dihydronaphth [2, 3-d] isoxazole-4, 9-dione, 2-benzimidoyl-3-hydroxy-1, 4-naphthoquinone, 2-(3--methoxyben-zimidoyl)-3-hydroxy-1, 4-naphthoquinone, 2-(3-pyridylcarbimidoyl)-4 hydroxy-1, 4-naphthoquinone, 2-(4-chlorobenzimidoyl)-3-hydroxy-6, 7-dimethyl-1, 4-naphthoquinone, 6-(or 7-) benzimidoyl-7 (or 6-)-hydroxy-5, 8-dihydroquinoline-5, 8-dione, 2 (N-methylbenzimidoyl)-3-hydroxy-1, 4-naphthoquinone, 2-benzoyl-3-hydroxy-1, 4-naphthoquinoe, 3, 5'-diphenyl-4-oxo-4, 9-dihydronaphth [2, 3-d] isoxazole-9-spiro-', 3', 4'-dioxazole) and 3, 5'-diphenyl-4, 5-dihydro-naphth [2, 1-d] isoxazole-5-spiro-2', 1', 3', 4'-dioxazol-4-one induced clearly parthenocarpic fruits. These compounds are of a new type of plant growth regulators and their chemical structures are different from those already known.2) One of these compounds, 2-benzimidoyl-3-hydroxy-1, 4-naphthoquinone (bendroquinone) was applied to emusculated tomato (cv. Fukuju Ni-Go) flowers. The parthenocarpic fruits showed the same development of fruit as by application of synthetic auxins, HCPA and 4CPA.3) The ovule development of the parthenocarpic fruits was histologically observed. The development of the endothelial cells induced by bendroquinone was not so active as that by HCPA for a period of two weeks after anthesis, but one week later, there was no difference in the development of the pseudoembryo between applications of the two chemicals.4) Bendroquinone isn′t easily soluble in water. It was formulated as 9% wettable powder and applied to tomato (cv. Beiju) flowers in a plastic green house as the setting agent. The fruit set percent and the yield of the first cluster were not so high as compared with the application of HCPA and 4CPA, but in case of the second, the third and the fourth clusters, they were higher. The fruit set percent and the total yield per plant by the application of 200ppm and 300ppm bendroquinone, 200ppm HCPA and 30ppm 4CPA were respectively 73.8% 15.92kg, 78.8% 15.66kg, 73.9% 16.03kg and 60.2% 13.34kg. The puffiness extent of the fruits was slight and there was no phytotoxicity on the plant.5) For induction of parthenocarpy by bendroquinone, the application at earlier stages of flower development was effective as compared with HCPA and 4CPA. The induction of parthenocarpy related closely to the volume and the time retained on the calyx. Therefore, addition of the spray adjuvant would be good for the induction.