Effect of endophytic fungi on the ability of Aphis craccivora Koch. in transmitting Bean common mosaic virus

Abstract

Bean common mosaic virus (BCMV) and its aphid vector, Aphis craccivora, are essential limiting factors in yardlong bean production. The previous study showed that endophytic fungi (EF), Lecanicillium lecanii (LL), and H5 could suppress virus titer in BCMV-infected plants by its vector Aphis craccivora. Therefore, elucidation of its mechanisms is a necessary study. This research aimed to study the ability of aphids reared on EF-treated and untreated control plants to transmit BCMV. The adult aphids had been raised on EF-treated yard-long beans for three generations. The 3rd generation of adult aphids was used as vectors to transmit BCMV after acquisition feeding on infected plants and inoculating feeding on healthy plants. The disease assessment parameters were observed at four weeks post-transmission. Generally, the population number of aphids on EF-treated plants was significantly lower compared to the control. The transmission of BCMV using the 3rd generation of aphids reared on EF-treated plants affected by the prolonged incubation period, lower disease incidence and severity score, and significantly lower virus titer compared to control. Moreover, the detection of BCMV by ELISA in aphids after virus transmission showed an adverse reaction, indicating that the virus from acquisition feeding was transmitted to plants during inoculation feeding. These results revealed that rearing aphids on EF-treated plants interfere with the aphids’ ability to transmit BCMV by decreasing virus acquired during acquisition and inoculation feeding.