Effect of Color of Light Emitting Diodes on the Development of Mycelial Growth, Conidiation and UV Radiation in Beauveria bassiana (Balsamo) Vuillemin

The entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin is one of the most important biological control agents used in IPM programs and has many commercial products. Similar to other insect fungal pathogens, B. bassiana can produces conidia for dispersal, transmission and infection to another insect pests via asexual reproduction. In the present study, mycelial growth, conidiation and UV resistance of B. bassiana under six colors of Light Emitting Diode (LED) conditions (red, blue, purple, green, yellow and white) is reported. Fungi cultured in dark chambers and exposured to LED light, B. bassiana hyphae grow continuously and did not differentiate in each treatment whereas conidia yield after exposure with different colors of LED light at 1, 3, 7, 14 and 24 hrs were significantly different. The results show that B. bassiana conidia yield were different significant, depending on color red light induced the highest conidia yield after exposure for 1 hr, while blue light had lowest conidia production, indicating that colors of LED light could stimulate conidiation of B. bassiana. All of the conidia were tested with UV tolerance, conidia of B. bassiana from red LED light was highly tolerant to UV radiation. The identification in this study of colors of LED light with relatively high conidia yield and UV tolerance will guide the selection of colors of LED light for researchers to develop an efficient B. bassiana as commercial product for biological control of insect pests in the future.