西花蓟马寄主选择性与寄主物理性状及次生物质的关系

Relationships between host plant selection of Frankliniella occidentalis and physical characteristics and secondary plant compounds of host foliage

为明确西花蓟马对6种蔬菜寄主(甘蓝、莴苣、黄瓜、茄子、芹菜和大蒜)的选择性,及其与寄主物理性状(颜色、叶毛数和叶片厚度)和次生物质(单宁酸、黄酮和总酚)的关系,采用非自由选择法,以每雌每天所孵化的子代若虫数为选择性指标,探讨其与寄主叶毛数、叶片厚度和次生物质的关系;采用叶碟法观察西花蓟马成虫对颜色的自由选择。以每雌每天所孵化的子代若虫数为选择性指标表明,西花蓟马对6种寄主的选择性,从大到小依次为甘蓝>莴苣>黄瓜=茄子>芹菜=大蒜,而西花蓟马对叶片颜色的选择趋性为甘蓝>莴苣>芹菜>黄瓜>大蒜>茄子。相关分析表明,西花蓟马的选择性与寄主的叶毛数(R=-0.073,p=0.890)、叶片厚度(R=-0.683,p=0.135)和总酚含量(R=-0.023,p=0.966)不存在显著相关关系,与寄主的单宁酸和黄酮的含量存在显著的负相关关系,相关系数分别为-0.828(p=0.042)和-0.820(p=0.046)。单宁酸和黄酮的含量对西花蓟马的寄主选择性有很大的影响,其含量越高越不利于西花蓟马的寄主选择。

The host plant selection of Frankliniella occidentalis to 6 vegetable host plants （cabbage, lettuce, cu- cumber, eggplant, celery, garlic） and the relationships between the host selection of F. occidentalis and the physi- cal characteristics （colour, density of trichomes and thickness of leaf） and content of secondary compounds （tan- nin, flavone and phenolic） of the host foliage were studied. With no-free choice method, the host plant selection of F. occidentalis was examined according to the offspring number per female per day as selection index. The rela- tionships between the host selection and physical characteristics, content of secondary compounds of the host foli- age were assessed, and the selection to colour was determined by the free choice of adult F. occidentalis to the host leaves. The results showed that the selection levels decreased in cabbage, lettuce, cucumber, eggplant, celery and garlic, in that order, according to the offspring number, while the selection of thrips to the color of cabbage, let- tuce, celery, cucumber, garlic and eggplant decreased in that order according to results of free choice. With the offspring number as selection index, the correlative analysis showed that the host selection of F. occidentalis was not significantly correlated with the density of trichomes （R =- 0. 073, p = 0. 890）, thickness （R =- 0. 683, = 0. 135） and the content of phenolic compounds （R =-0. 023, p=0. 996） of host foliage, but it was significantlynegatively correlated with the content of tannin and flavone in foliage,and correlation coefficients were --0. 828 （p=0.042）and -0. 820（p O. 046）, respectively. The tannin and flavone contents had significantly effects on the host selection of F. occidentalis, and the higher the content of tannin and flavone, the less favor for selection.