Producción de Lecanicillium (= Verticillium) lecanii en diferentes sustratos y patogenicidad

Abstract

The conidial production of the fungus Lecanicillium lecanii cultivated in different substrates (nutrition media + supports) and its pathogenicity were determined. The evaluated media were: sorghum, rice grain, broken rice grain (“granillo”), rice polish (“pulido”) and as supports sugar cane leftover “bagazo”, rice husk and corn cob “olote”. The combination of media and supports provided twelve treatments plus a control constituted by rice alone. The production of conidia displayed statistical differences (p≤ 0.05) among treatments; those with larger conidia production were sugar cane leftover (bagazo) + rice (839.7 ± 1.2 x 106 g-1) and sorghum + corn cob (825.8 ± 1.7 x 106 g-1). Although polished of rice was the less efficient medium for production, all combinations where it was included resulted superior to rice alone. Rice showed the smallest production of conidia (265.4 ±1 x 106 g-1). Also, the media and support where it was produced affected the pathogenicity of L. lecanii on Toxoptera aurantii and Aphis gossypii. The aeration favored by the support marked the difference between treatments and the control. Results indicated that the culture medium is important for the massive production of L. lecanii; besides, they indicate that the pathogenicity of the fungus was also affected by the culture medium.