Development of Colletotrichum gloeosporioides isolated from green pepper in different culture media, temperatures, and light regimes

Abstract

Control of anthracnose in green pepper involves the use of resistant varieties and/or fungicides. The selection of varieties and efficient products demands great amounts of conidia as inoculum. It is thus necessary to optimize the production of Colletotrichum gloeosporioides conidia in the laboratory, establishing the best conditions for fungus development. The present study aimed at determining the most favorable culture media, temperature, and light conditions for the production of fungus inoculum. The fungus was isolated from green pepper fruits (Capsicum annuum L.) and transferred to four culture media (PDA, oat, filtered pepper extract, and autoclaved pepper extract), under different temperatures (15, 20, 25, 30, and 35 o C) and light conditions (24h dark, and 24h light). Colony growth was evaluated after 7 and 12 days of incubation. No differences were found between the culture media. However, the greatest number of conidia was obtained from colonies grown in oat medium at 25ºC. Temperatures of 20 and 25ºC were the most favorable for colony growth and sporulation. Higher sporulation was obtained under incubation in constant light. Cultivation of C. gloeosporioides in oat medium, at 25ºC, and constant light is recommended. Key words: Capsicum annuum, anthracnose, mycelium growth, sporulation DESENVOLVIMENTO DE Colletotrichum gloeosporioides ISOLADO DE PIMENTÃO EM DIFERENTES MEIOS DE CULTURA, TEMPERATURAS E REGIMES DE LUZRESUMO: O controle da antracnose causada por Colletotrichum gloeosporioides em pimentão, envolve o emprego de variedades resistentes e/ou fungicidas. A seleção de variedades e de produtos eficientes demanda grande quantidade de inóculo. Assim, é necessário otimizar a produção de conídios em laboratório, estabelecendo as melhores condições para tal. O presente trabalho teve por objetivo determinar o meio de cultura, a temperatura e o regime de luz mais favoráveis à produção de inóculo do fungo. O isolado fúngico foi obtido de frutos de pimentão e cultivado em quatro meios de cultura (BDA, aveia, extrato de pimentão filtrado e extrato de pimentão autoclavado), sob diferentes temperaturas (15, 20, 25, 30 e 35 ºC) e regimes de luz (24 h de escuro, 24 h de luz). O crescimento da colônia foi avaliado aos 7 e 12 dias, não sendo observadas diferenças entre os meios, aos 12 dias após a incubação. Entretanto, maior produção de conídios foi obtida de colônias crescidas em aveia a 25ºC. As temperaturas de 20 e 25ºC foram as mais favoráveis para o crescimento da colônia e para esporulação do fungo. A produção de conídios foi maior quando em incubação sob luz contínua diferindo da incubação sob escuro total, aos 12 dias. Para obtenção de inóculo, indica-se o cultivo de C. gloeosporioides em meio de aveia, a 25ºC, sob luz contínua, por 12 dias.

EFFECTIVENESS OF CULTURAL PARAMETERS ON THE GROWTH AND SPORULATION OF <i>COLLETOTRICHUM GLOEOSPORIOIDES</i> CAUSING ANTHRACNOSE DISEASE OF MANGO (<i>MANGIFERA INDICA</i> L.)

“…Among the evaluated media, MEA was found to be most suitable over other media which showed higher growth of the respective isolates, corroborating with the results (Sudhakar, 2000;Rani and Murthy, 2004). In the other study, it have been noticed that sporulation of C. gloeosporioides isolated from capsicum was maximum in oat medium at 25°C (Mello et al, 2004). Earlier, reports showed that PDA and CWA was ideal medium for growth of C. gloeosporioides, as the coconut watery endosperm contains considerable amounts of lipids (1.26%), proteins (2.1%), carbohydrates and minerals suitable for maximum growth (Santoso et al, 1996).…”

Cold plasma as a novel treatment to reduce the in vitro growth and germination of Colletotrichum species

“…Conidial suspensions for each of the five isolates were produced by placing a 5 mm 2 mycelial disc from a 4‐day‐old culture on to fresh half‐strength PDA and incubating at 25 ± 1 °C under continuous light according to Mello et al (). After 20 days, conidia were washed from the cultures with 20 mL sterile deionized water and filtered through three layers of sterile gauze to remove the mycelial fragments.…”

Melatonin Mitigates the Infection of Colletotrichum gloeosporioides via Modulation of the Chitinase Gene and Antioxidant Activity in Capsicum annuum L.

“…Based on the results of the preliminary experiment (hyphal extension–inhibition assay), we selected a 100 µM concentration of melatonin for C. gloeosporioides . Two-month-old pepper seedlings were inoculated (sprayed) with C. gloeosporioides microspores described by Mello and Pessoa et al [ 55 , 56 ], while the control plants were sprayed with distilled water. After inoculation, the plant leaves were sampled at different periods (0, 12, 24, 48, and 96-h post-inoculation).…”