抄録
紫外線照射で生成するカンキツ類のファイトアレキシンであるスコパロン(6, 7-ジメトキシクマリン)の果皮および葉での生成量の品種間差異を検討した.カンキツ類26種・品種の果皮と29種・品種の葉に20分間の紫外線照射を行った.発育期(8月)の葉および果実では成熟期(12月)のそれらより生成量が低かった.幼葉では'吉田ポンカン', 'ユーレカ'レモン, キンカン類などが, 成葉では'セミノール', ヒュウガナツ, 'ユーレカ'レモンが, また, 幼果では, 'ユーレカ'レモン, ネイハキンカン, 成果では, '津之香', 'ロビンソン', ネイハキンカンの生成量がそれぞれ多かった.また種・品種間あるいは器官別でも, 紫外線によるスコパロン生成量には大きな差異があり, また生成量の変化にも差異が認められた.
Ultraviolet (UV) radiation induced production of phytoalexin scoparone (6, 7-dimethoxycoumarin) in the leaves and flavedo of various citrus cultivars. Using high performance liquid chromatography (HPLC) measured scoparone in the citrus leaves and fruits after radiated with UV. The amounts of scoparone in young leaves and fruits (harvested in August) were less than those in mature specimens (harvested in December). Among the cultivars, abundant scoparone was induced in young leaves of lemon (Citrus limon (L.) Burm. f.), Meiwa kumquat (Fortunella crassifolia Swingle) and Ponkan (C. reticulata Blanco). Matured leaves of lemon, Hyuganatsu (C. tamurana hort. ex Tanaka) and 'Seminole' tangelo also produced abundant scoparone. In August, Meiwa kumquat and lemon, and in December, Meiwa kumquat, 'Tsunokaori' and 'Robinson' fruits were induced to produce abundant scoparone by UV radiation. Duration of changes in scoparone synthesis differed among citrus cultivars, organs and growth phases.
