羊踯躅花期花瓣类胡萝卜素的含量变化

Changes of carotenoids content in flower petal of Rhododendron molle during flower development

为揭示羊踯躅的花瓣花色形成机理和花色新品种选育提供参考。以羊踯躅花发育的4个时期花瓣为材料,采用高效液相色谱法(HPLC法)测定4种类胡萝卜素的含量,并分析其变化规律。结果表明,高效液相色谱法可以对羊踯躅花瓣中的叶黄质、玉米黄质、α-胡萝卜素和β-胡萝卜素完全分离并进行分析。羊踯躅在花蕾期已经有大量类胡萝卜素积累。β-胡萝卜素在花发育过程中,其含量远高于α-胡萝卜素、叶黄质和玉米黄质,α-胡萝卜素的含量在整个花发育过程中含量均较低;β-胡萝卜素随着花的发育,其含量先降后升,在盛开期达到最高(95.25μg/g FW),占检测类胡萝卜素总量的92.89%;叶黄质和玉米黄质则相反,先升后降,在花朵膨大期含量最高(48.15μg/g FW和18.71μg/g FW),分别占检测类胡萝卜素总量的42.18%和16.39%,在盛开期含量均较低。认为β-胡萝卜素是影响羊踯躅花瓣着色的一个主要因素,其含量变化与羊踯躅的花色形成密切相关。

The changes of carotenoids content in the flower petal of Rhododendron molle during flower development were in-vestigated. Four kinds of carotenoids were separated and their contents were analyzed by high performance liquid chromatog-raphy （HPLC）. The results showed that there were a large number of carotenoids accumulated in the petal during the flower early development. The content of β -carotene was much higher than the other carotenoids during the flower development while the content of α-carotene was always low. The content of β-carotene tended to decline at the flower expanding stage and then rise to 95. 25 μg/g FW at the full flowering stage,accounting for 92. 89% of the total carotenoid content. On the contrary,the content of lutein and zeaxanthin rose to 48. 15 and 18. 71 μg/g FW at the flower expanding stage, accounting for 42. 18% and 16. 39% of total carotenoid content,respectively whereas their contents were low at the full flowering stage. It was indicated that p-carotene played an important role in the coloring of R. molle flower,and the changes of p-carotene content was closely related with the flower color formation of R. molle.