Effects of carbon concentration and carbon-to-nitrogen ratio on growth, conidiation, spore germination and efficacy of the potential bioherbicide Colletotrichum coccodes (original) (raw)
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Stability of Colletotrichum truncatum in Culture Influences Mycoherbicide Efficacy
Mycologia, 1994
Colletotrichum truncatum, a potential mycoherbicide for control of hemp sesbania, formed spontaneous variants on agar medium. The predominant variant produced more spores than the wild type on potato dextrose agar but the wild type produced more spores on Czapek-Dox agar. Spore yield of both types was greatly reduced on Czapek-Dox. In liquid culture, the variant spontaneously arose and gradually displaced the wild type. Although the variant produced more spores in liquid culture, it had reduced virulence. Displacement of wild type strains by similar variants in liquid fermentation may constrain production of this mycoherbicide and should be considered during the preparation of C. truncatum inocula.
Journal of Medicinal Plants Research, 2014
The fungal organism Colletotrichum gloeosporioides is the causative agent of anthracnose disease of Citrus fruits. It is recently introduced as a potential producer of anticancer metabolite paclitaxel. Here, we introduce the optimal conditions for growth and sporulation of C. gloeosporioides. We have considered four fungal culture media, that is potato dextrose agar (PDA), carnation leaf agar (CLA), potato carrot agar (PCA) and water agar (WA), based on which sporulation inducers like Watman or Fabriano filter papers could be added, and evaluated both for vegetative growth and sporulation. Three light regimens, i.e. continuous light, 16/8 hrs light/darkness, and continuous darkness were applied in combination with the culture media. All experiments were tracked on 7th, 15th, 21st, and 30th day after incubation. At 28°C, PDA and PCA culture media, under continuous light, provided the best condition for C. gloeosporioides maximal growth. Decreasing light periods decreased the fungal growth. Furthermore, fungal sporulation showed a high dependence on light, temperature and culture medium in use. Under 16/8 h light/darkness interval at the same temperature C. gloeosporioides sporulation was at its maximum on Fabriano paper placed on PDA medium. At a lower temperature, that is 22°C, C. gloeosporioides sporulation on the same culture media was highly defected. Furthermore, aging generally increased the fungal sporulation.
Effect of different factors on sporulation of Colletotrichum coffeanum
2015
The effect of different factors on sporulation of Colletotrichum coffeanum was investigated. Result showed that V8 and PDA media were suitable for the growth of C. coffeanmum. On the contrary, the content of the media gave a significant impact on sporulation. The media content increased then it would greatly increase the sporulation. 12 h light/dark photoperiod (12:12 L:D; 10000 lux, fluorescent lamp) was the most suitable light condition for C. coffeanmum sporulation, compared with constant darkness (continuous darkness; CD) and constant illumination (continuous light; CL; 10000 lux, fluorescent lamp). Moreover, the growth rate in the 28 day showed the fastest growing culture. It is concluded 10 ml PDA medium and incubated 28 days under natural light conditions was the best time of sporulation.
Effect of nutrients on spore germination of Gliocladium roseum and Ophiostoma piceae
Wood and Fiber Science, 2000
Biological control agcnts that are applied as spore suspensions must gerrninatc to exert their desired effects. Nutrients are one possible factor that can be manipulated to enhance spore germination and subsequent microbial colonization of wood. Sugar alcohols, inorganic and organic nitrogen compounds (amino acids) were evaluated for their ability to selectively enhance germination of spores (conidia) of Glioclodium roseurn. While sugar alcohols and inorganic nitrogen compounds showed no selective cffcct on sporc gcrmination of G. roserlm, some of the amino acids, notably L-phenylalanine and Palanine, selectively enhanced germinati~n of G. rosrum over Ophiostoma piceae.
Biological Potencial of Colletotrichum typhae H.C Greene mycoherbicide for Typha domingensis Pers
The anthropic interference in aquatic ecosystems, favors the disordered colonization of T. domingensis, damaging the production of hydroelectric power and river traffic. Thus, the objective of this study was to evaluate the potential of C. typhae as a mycoherbicide in the control of T. domingensis, in vitro and in greenhouse. 107 samples of symptomatic T. domingensis leaves were collected in flooded areas of rivers in Brazil, with identification and isolation of the collected fungal species. The concentration of inoculum was determined to evaluate the incidence and severity of the disease, the influence of temperature on mycelial growth and conidia germination, the effect of temperature and leaf wetness period on T. domingensis infection by C. typhae and the host range test. The growth of the colonies of C. typhae was higher at 25 to 30 ºC, there was no interference of the photoperiod on germination of the spores, but the highest percentage of germination occurred at 17.39 ºC. The i...
The impact of nutrition on spore yields for various fungal entomopathogens in liquid culture
World Journal of Microbiology & Biotechnology, 2003
Spore yields were measured for various fungal entomopathogens grown in six nutritionally different liquid media with low and high carbon concentrations (8 and 36 g l )1 , respectively) at carbon-to-nitrogen (C:N) ratios of 10:1, 30:1 and 50:1. Six fungi were tested: two Beauveria bassiana strains, three Paecilomyces fumosoroseus strains and one Metarhizium anisopliae strain. Spore yields were examined after 2, 4 or 7 days growth. In general, highest spore yields were obtained in media containing 36 g/l and a C:N ratio of 10:1. After 4 days growth, highest spore yields were measured in the three Paecilomyces isolates (6.9-9.7 · 10 8 spores ml )1 ). Spore production by the B. bassiana isolates was variable with one isolate producing high spore yields (12:2 Â 10 8 spores ml )1 ) after 7 days growth. The M. anisopliae isolate produced low spore concentrations under all conditions tested. Using a commercial production protocol, a comparison of spore yields for the coffee berry borer P. fumosoroseus and a commercial B. bassiana isolate showed that highest spore concentrations (7:2 Â 10 8 spores ml )1 ) were obtained with the P. fumosoroseus isolate 2-days post-inoculation. The ability of the P. fumosoroseus strain isolated from the coffee berry borer to rapidly produce high concentrations of spores prompted further testing to determine the desiccation tolerance of these spores. Desiccation studies showed that ca. 80% of the liquid culture produced P. fumosoroseus spores survived the air-drying process. The virulence of freshly produced, air-dried and freeze-dried coffee berry borer P. fumosoroseus blastospores preparations were tested against silverleaf whiteflies (Bemisia argentifolii). While all preparations infected and killed B. argentifolii, fresh and air-dried preparations were significantly more effective. These results suggest that screening potential fungal biopesticides for amenability to liquid culture spore production can aid in the identification of commercially viable isolates. In this study, P. fumosoroseus was shown to possess the production and stabilization attributes required for commercial development.
Comparative mycelial and spore yield by Trichoderma viride in batch and fed-batch cultures
Annals of Microbiology , 2012
The effects of cultural parameters such as carbon and nitrogen source and environmental factors including temperature and pH were investigated on spore and mycelial yield of Trichoderma viride, which has potential as a biocontrol agent against species of Fusarium in batch culture and fed-batch culture where there was limiting nutrient. The results obtained indicated that growth and sporulation of T. viride were greatly influenced by various carbon and nitrogen sources, and by environmental factors such as pH and temperature. Mannitol, wheat bran and rice bran as sole carbon sources appear to stimulate high mycelial growth and spore yield in fed-batch culture. Growth and sporulation were also favoured by NaNO3, peptone and NH4SO4 as the nitrogen sources in fed-batch and batch cultures. Maximum growth and sporulation was between pH 4.5 and 6.0. Temperatures between 30 and 37 °C were good for mycelium growth of T. viride while temperatures between 30 to 45 °C were good for sporulation. The amount of spore and mycelium produced and the time required for attainment of maximum spore yield increased with increasing carbon and nitrogen source in batch culture. The final spore yield obtained in fed-batch culture was two times higher than the apparent spore-carrying capacity of batch culture. These results show that T. viride is capable of growing and sporulating with varied nutritional and environmental conditions, and, therefore, this strain of T. viride may be useful as a biocontrol agent under diverse physiological and environmental conditions.