芹菜植株挥发物对蔬菜烟粉虱的驱避作用

Repellent effect of celery volatiles on Bemisia tabaci

为了进一步明确芹菜挥发物对烟粉虱的驱避作用,应用固相微萃取法提取和GC/MS分析,对芹菜植株挥发物进行了鉴定,分别用1 000 mg/m^3、2 000 mg/m^3和4 000 mg/m^3的柠檬烯、α-蒎烯和β-石竹烯3种物质对烟粉虱的嗅觉反应进行了测定,在此基础上,应用4 000 mg/m^3的柠檬烯和α-蒎烯作为驱避剂分别进行模拟大棚辣椒的驱虫试验。结果表明,不同生育期芹菜茎叶中的挥发物在种类和含量上均有差异,苗期芹菜茎叶中分离到挥发物14种,而抽薹期芹菜茎叶中分离出20种,且包含苗期的全部物质;苗期茎叶中柠檬烯和α-蒎烯的相对含量高于抽薹期。嗅觉实验发现,较高浓度的柠檬烯和α-蒎烯对烟粉虱具有较强的驱避作用,而β-石竹烯对烟粉虱的驱避作用不明显。柠檬烯田间驱虫试验研究表明,在一端开口的小区中,柠檬烯对田间辣椒烟粉虱的驱避效果随着距离的延长而下降。在开口的一端再种苘麻诱集植物,处理4 h后,第1行、第4行和第7行的虫口减退率分别比没有诱集植物的提高了13.19%、78.43%和122.85%。小区远端封闭时,驱避剂附近的辣椒上烟粉虱虫量下降,但烟粉虱聚集在小区的远端辣椒上。α-蒎烯与柠檬烯对不同小区辣椒上的驱虫作用基本一致,但驱虫效果较柠檬烯弱。结果证明柠檬烯和α-蒎烯是芹菜重要的驱烟粉虱的活性物质。大棚中应用驱避剂驱虫时,必须有烟粉虱的迁出通路,或有诱集避难场所供烟粉虱栖息。

In order to further clarify the repellent effect of celery volatiles on Bemisia tabaci, the volatiles of celery plants were identified by solid phase microextraction and GC/MS analysis. The reactions of B. tabaci were studied by olfactometer with 1 000 mg/m^3, 2 000 mg/m^3 and 4 000 mg/m^3 of limonene,α-pinene and β-carnosine respectively, on this basis, the repellent experiments on pepper in greenhouse were carried out by using 4 000 mg/m3 limonene and α-pinene respectively. The results showed that the volatiles from celery stems and leaves at different growth stages were different in both kinds and contents. There were 20 kinds of volatiles in the stems and leaves of bolting celery, while they were 14 kinds in seedling celery, and the latter were all included in the former. The relative contents of limonene and α-pinene in seedling were higher than that of the bolting period. Olfactory experiments showed that the higher concentration of limonene and α-pinene had a strong repellent effect on B. tabaci, while β-carnosine had no obvious effect. The field tests showed that the repellent effect of limonene on B. tabaci on the pepper decreased with the extension of distance. When piemarker were planted as trap plant at one end of the opening, the population decline rate increased 13.19%, 78.43%, 122.85% than the non-trapping plants in the first, fourth and seventh row respectively after 4 hours. When the greenhouse was closed at the distal end, the amount of B. tabaci on the pepper decreased near the repellent, but the whitefly gathered on the remote pepper.α-pinene had the same mechanism as the limonene repellent on different areas of pepper, while it had weaker repellent effect than the limonene. The results indicated that limonene and α-pinene from celery were important repellent for B. tabaci. When repellents were used in the greenhouse, it would have better effect if there were channels for B. tabaci to emigrate or had the shelters for B. tabaci habitat.