烟粉虱危害对青萝卜白心的影响

Study on Silver Appearance in Xylem of Green Radish Damaged by Bemisia tabaci

烟粉虱危害青萝卜造成其叶脉、表皮及木质部变白(白心)。随着接虫密度的增大,青萝卜叶脉变白株率、外表皮退绿株率和白心率依次增加,单株有虫40头以下时,青萝卜白心率在10%以下;青萝卜定苗期和膨大期接虫,白心率分别是57.14%和75.00%,定苗期和膨大期是烟粉虱危害的敏感期。

Bemisia tabaci can induce silver appearance in the vein, cuticle, and xylem of green radish. The relationship between feeding population of Bemisia with silver appearance rate is direct ratio: the higher density of bemisia, the higher ration of silver appearance in vein, cuticle, and xylem of green radish. The ration of silver appearance in xylem of green radish was under 10% when the Bemisia density was under 40 on each radish plant。 The stage between seedling and the root stock expanding is the sensitive period of bemisia damage: the silver appearance symptom in xylem ratio was 57.14%, and 75% respectively when feeding bemisia in these two periods.