Crescimento e esporulação de isolados de Verticillium lecanii sob diferentes fatores ambientais

Abstract

Resumo -O objetivo deste trabalho foi avaliar o crescimento e a esporulação de dois isolados (JAB 02 e JAB 45) de Verticillium lecanii (Zimm.) Viégas, submetidos a diferentes valores de pH (4, 5, 6, 7, 8, 9) inicial do meio de cultivo sólido, de temperatura (19, 22, 25, 28 e 31 o C) e fotoperíodo (0, 12 e 24 horas). Após 20 dias de cultivo, não se observou efeito do pH inicial do meio no crescimento e esporulação dos isolados, exceto no pH 4,0 que reduziu o crescimento. A ausência de iluminação proporcionou a melhor condição para o crescimento de JAB 02 (32,70 mm) e JAB 45 (32,67 mm). Não houve efeito do fotoperíodo na produção de esporos. As melhores temperaturas para o crescimento de JAB 02 foram 19, 22 e 25 o C e para JAB 45 foram 19 e 25 o C. Este último isolado apresentou melhor esporulação a 19 e 22 o C, mas a temperatura não influenciou a esporulação de JAB 02. Não houve desenvolvimento dos isolados a 31 o C.Termos para indexação: fungo entomopatogênico, pH, temperatura, fotoperíodo, controle de pragas. Growth and sporulation of Verticillium lecanii isolates under different environmental conditionsAbstract -This research aimed to evaluate the growth and sporulation of two Verticillium lecanii (Zimm.) Viégas isolates cultivated on solid medium with different initial pH values (4, 5, 6, 7, 8 and 9), exposed to different temperatures (19, 22, 25, 28 and 31 o C) and photoperiods (0, 12 and 24 hours). There was no substantial effect of the initial pH values on growth and sporulation of both isolates twenty days after inoculation, except at pH 4.0 in which the growth was significantly reduced. Absence of light promoted the best growth of JAB 02 (32.70 mm) and JAB 45 (32.67 mm) isolates but there was no effect of photoperiod on sporulation. The best temperatures for growth of JAB 02 were 19, 22 and 25 o C and for JAB 45, 19 and 25 o C. The latter isolate sporulated most at 19 and 22 o C and there was no effect of temperature on sporulation of JAB 02. None of the isolates developed at 31 o C.

Mycelia growth and sporulation of Fusarium chlamydosporum species complex under different culture conditions

“…Culture media including complex carbohydrates are more favorable for the sporulation of fungi because these carbohydrates are better suited for the production of spores than of vegetative hyphae. Culture medium composition, temperature and light have been found to determine the quantity and quality of the mycelial growth and sporulation of phytopathogens (DHINGRA;SINCLAIR, 1995), and environmental factors such as pH, light and temperature have been reported as limiting factors in the optimization of the production of a fungus (MONTEIRO et al, 2004).…”

Variability of aggressiveness and virulence of Phytophthora palmivora influencing the severity of papaya fruit rot in postharvest in Bahia, Brazil

“…Monteiro et al, (2004) also observed, for the same strains, differences in preferential temperatures of sporulation. In addition, sporulation is affected by cultivation conditions, such as carbon source, light, mycelium lesions (Casas-Flores et al, 2004), nitrogen source and pH (Steyaert et al, 2010).…”

Efeito da temperatura sobre o crescimento e esporulação in vitro de fungos hiperparasitas de Asperisporium caricae

“…Outros autores observaram diferenças no crescimento micelial e esporulação dos isolados, quando esses foram incubados a diferentes temperaturas, havendo maior crescimento e esporulação quando tais temperaturas eram amenas (Monteiro et al 2004, Moreira & Mayo 2007 …”