2010 Fiscal Year Final Research Report

Investigation of Mechanism of the Temporal Rise in UVA Reflectance of Gentian Cut Flowers and Feasibility of Application to Judging Freshness

Research Project

Project/Area Number	20580282
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Agricultural information engineering
Research Institution	Iwate University
Principal Investigator	SHONO Hiroshi Iwate University, 農学部, 准教授 (90235721)
Project Period (FY)	2008 – 2010
Keywords	切り花 / リンドウ / 分光計測 / 紫外線画像 / 画像計測
Research Abstract	Previously, we found the significant temporal rise of UVA reflectance on petals of Gentian cut flowers correspondently with their inflorescence, but its mechanism has not been elucidated yet. Therefore, in this study, we investigated distribution of UVA reflectance of petals for the elucidation. Consequently, we found that reflectance rise is more prominent on inner surface than outer one. Then, we concluded that the substance of this phenomenon could exist in adaxial epidermis. Furthermore, we found that the the reflectance rises correspondently with pH and water content of petals. After all, we concluded that the main substance is some kind of cinnamic acid existing in adaxial epidermial cell which fluoresces in both UVA and Blue band. It is noteworthy that the yield of UVA fluorescence is strongly susceptible to pH which could change with senescence of flowers.