菊花花部特征及花冠精油组分与访花昆虫的相关性

CORRELATION BETWEEN FLORAL TRAITS OF CHRYSANTHEMUM (DEN-DRANTHEMA MORIFOLIUM) AND INSECT VISITORS

菊花(Dendranthema morifolium)是异花授粉植物,具有自交不亲和特性。其自然授粉的主要媒介为蜂类和蝶类。我们对19个菊花品种的花色、花朵繁密度、花冠直径、管状花花盘直径、株高以及花冠精油组分与访花蜂数和访花蝶数的相关性进行了研究。结果表明,黄花色系较吸引西方蜜蜂(Apis mellifera)访花;菊花的花朵繁密度、花冠直径、管状花花盘直径均与访花蜂数有显著相关性,而株高与访花蜂数无相关性。大红蛱蝶(Vanessa indica)青睐红色花,其访花蝶数与花朵繁密度、管状花花盘直径均有显著相关性,而花冠直径和株高与访花蝶数无相关性。经气相色谱-质谱(GC-MS)分析得知,不同菊花品种花冠精油的组分不同,其主要成分均为单萜和倍半萜类及其含氧衍生物;并且不同品种含有某些特定的花冠精油组分,其中樟脑萜(r=–0.909,p<0.05)和6,10,14-三甲基-2-十五酮(r=0.882,p<0.05)与访花蜂数呈一定的相关性,α-萜品醇(r=0.979,p<0.01)、顺柠檬烯氧化物(r=0.979,p<0.01)、金合欢烯氧化物(r=0.979,p<0.01)、p-mentha-6,8-dien-2-ol,cis-(r=0.973,p<0.01)、p-menth-1-en-8-ol(r=0.962,p<0.01)和4-萜品烯醇(r=0.957,p<0.05)与访花蝶数呈一定相关性。

Aims Chrysanthemum （Dendranthema morifolium） is a self-incompatible allogamous plant. Its main pollination vectors are bees and butterflies. Our aim is to investigate and evaluate the effects of flower color, corolla density, corolla diameter, tubular flower diameter, plant height and essential oil components on attracting insect visitors. Methods We investigated the floral traits of 19 chrysanthemum cultivars. Five cultivars with different floral traits were selected for identification of essential oil components using a Thermo Finnigan TRACE GC/DSQ spectrometer, and data on essential oil components were analyzed by SPSS （Analysis of Variance, stepwise and correlation）. Important findings Bees （Apis mellifera） preferred yellow color flower to others including orange yellow, red, mauve, orange and pink. The number of visiting bees was significantly correlated with corolla density （r=0.715, p〈0.01）, indicating that the effect of a colony was more significant than the size of a single flower head. For all tested traits of a single flower head, tubular flower diameter had the most significant influence on attracting bees （r=0.622, p〈0.01）, followed by corolla diameter （r = -0.502, p〈0.05）. Butterflies （Vanessa indica） preferred red color flowers, and tubular flower diameter significantly influenced the number of pollinating butterflies （r=0.635, p〈0.01）. Results suggested that rewards from the flowers were the dominating attractive factors to visitors. The effect of single flower head on number of visiting butterflies was more significant than corolla density （r=0.487, p〈0.05）. In all tested traits of a single flower head, flower color and tubular flower diameter were the main influencing factors on numbers of visiting butterflies. The main essential oil components, such as camphor （rbees= -0.191, p〉0.05; rbutterflies=0.507, p〉0.05） and borneol （rbees=0.354, p〉0.05; rbutterflies= -0.387, p〉0.05） had little correlation with number of visiting insects, whereas some specific essential oil components, such as camphene （r= -0.909, p〈0.05）, 2-pentadecanone,6,10,14-trimethyl- （r=0.882, p〈0.05） showed significant correlations with number of visiting bees, and α-terpineol （r=0.979, p〈0.01）, cis-limonene oxide （r=0.979, p〈0.01 ）, E-farnesene epoxide （r=0.979, p〈0.01 ）, p-mentha-6,8-dien-2-ol, cis- （r=0.973, p〈0.01）, p-menth-1-en-8-ol （r=0.962, p〈0.01） and p-menth-1-en-4-ol, [R]-[-]-（r=0.957, p〈0.05） showed significant correlations with number of visiting butterflies. Therefore, some specific essential oil components were important in attracting visitors.