Chlamydospore formation by Corynespora cassiicola

Abstract

The fungus Corynespora cassiicola is an important pathogen that causes necrotic lesions in several plant species. Saprophytism and parasitism habits of plants are common survival strategies for this pathogen. Few studies referred to the formation of chlamydospores by C. cassiicola. The objective of this study was to test the formation of chlamydospores by several C. cassiicola isolates from different agronomic crops and weeds. Fifteen isolates were analysed by in vivo and in vitro tests. Six isolates from four host plants (Cucumis sativus, Lantana camara, Malpighia glabra and Vernonia cinerea) were able to produce chlamydospores, both in vitro and in vivo. In vitro, chlamydospore production was highest for the Malpighia glabra isolate and one Cucumis sativus isolate, intermediate for two other C. sativus isolates, and lowest for the Vernonia cinerea and Lantana camara isolates. However, no difference in the relative number of chlamydospores produced among isolates was observed in vivo.

Morphological changes in response to environmental stresses in the fungal plant pathogen Zymoseptoria tritici

“…Their morphology matched the chlamydospores described in other fungi: spherical, thick-walled cells with a high lipid content that form either intercalated or at the ends of filamentous hyphae and occasionally on pseudohyphae 20,71 . We also showed that these cells were able to survive and germinate following several stresses that killed other cell types, including desiccation and high and low temperatures, consistent with the function of chlamydospores as long-term survival structures in other fungi 19–21,72 . We conclude that Z. tritici produces chlamydospores.…”

In-Vitro Application of a Qatari Burkholderia cepacia strain (QBC03) in the Biocontrol of Mycotoxigenic Fungi and in the Reduction of Ochratoxin A biosynthesis by Aspergillus carbonarius

“…The microscopic observation of the fungal mycelium exposed to QBC03 culture supernatant showed fragmentation, granulations and swellings. In addition, in the present study, the appearance of chlamydospores ( Figure 4E), which are a general indication of fungal growth suspension and dormancy [28,29], showed that the QBC03 culture supernatant created an environment not favorable for the growth and propagation of A. carbonarius.…”

The fungal pathogen Corynespora cassiicola: A review and insights for target spot management on cotton and Soya bean

“…The integration of crop rotation with non‐hosts, destruction of plant residues, sanitary practices of seeds, germplasm genetic resistant to target spot and fungicide applications help with disease management and reduction of yield losses on cotton and Soya bean (Galbieri et al., 2014; Hartman et al., 2011). Crop rotation assists in breaking the disease cycle; however, C. cassiicola can be a saprophyte (Cai et al., 2006) with the ability to survive in the soil and plant debris by means of chlamydospores (Olive et al., 1945; Oliveira et al., 2012). Biological control with optimized microbiomes remains unexplored, and biotechnological solutions have been recommended to prevent losses and to improve yields on cotton and other crops (Tarazi et al., 2019).…”

“…The presence of a thick dark hilum is a distinctive feature of the C. cassiicola conidia (Ellis & Holliday, 1971). Chlamydospore formation of C. cassiicola isolates allows the pathogen to survive in soil or plant debris in unfavourable conditions or in the absence of the host (Olive et al., 1945; Oliveira et al., 2012). Survival on plant debris is the source of primary inoculum (Almeida et al., 2001).…”