''Mycocentrospora acerina'' is a deuteromycete

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...

that is a plant pathogen.

Hosts and symptoms

''Mycocentrospora acerina'' has a wide host range effecting vegetables, ornamentals and weeds. Umbelliferous (carrot family) crops are particularly vulnerable and among the most economically important of the hosts. ''Mycocentrospora acerina'' causes an important post-harvest disease named "liquorice rot" in carrots which have been the most studied host. During the growing stage of carrots, the pathogen can cause damping-off and death of seedlings, stunting, early senescence, and leaf lesions that are brown necrotic flecks. Once the carrots are in storage the liquorice rot occurs where root lesions appear that are black in color.

Disease cycle

''Mycocentrospora acerina'' is a deuteromycete (no sexual stage) soil-borne fungus that is a root inhabitant. The life cycle starts and ends with the

chlamydospore A chlamydospore is the thick-walled large resting spore of several kinds of fungi, including Ascomycota such as '' Candida'', Basidiomycota such as '' Panus'', and various Mortierellales species. It is the life-stage which survives in unfavourable ...

. The chlamydospore is a thick walled, dark pigmented resting spore that overwinters in the soil or plant debris and can stay dormant for several years without losing viability. It will only germinate in the soil when it senses a host root nearby or when conditions are right when it is on the surface. In the soil it will produce germ tubes and mycelial growth that will infect the root through a wound and begin producing more chlamydospores. On the surface the chlamydospore will produce a short germ tube with terminal conidia attached that will disperse through water and infect a leaf. The leaf infection will create a lesion where

conidiophores A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to ...

will produce conidia. The conidia will then be dispersed through rain splash and infect other leaves. Some conidia that end up in the soil will convert into chlamydospores for survival.

Environment

''Mycocentrospora acerina'' is found in temperate climates and grows best at 18 degrees Celsius (65 degrees Fahrenheit). The temperate climate leads to long refrigeration time for the carrots that induces the storage rot. Rainfall is needed to induce sporulation and dispersal of conidia. The pathogen has a greater impact in sandy soils and this is hypothesized to be that the host roots take more wounds in sandy soils and that there is less microflora to buffer the pathogen. Growing hosts plants in rotation allows for the buildup of chlamydospores in the soil from infected plant litter, allowing for greater disease rates over time.

Other

Falcarindiol Falcarindiol is a polyyne found in carrot roots which has antifungal activity. Falcarindiol is the main compound responsible for bitterness in carrots. Falcarindiol and other falcarindiol-type polyacetylenes are also found in many other plants of ...

(cis-heptadeca-1,9-diene-4,6-diyne-3,8-diol) is a

polyacetylene Polyacetylene (IUPAC name: polyethyne) usually refers to an organic polymer with the repeating unit . The name refers to its conceptual construction from polymerization of acetylene to give a chain with repeating olefin groups. This compound ...

found in carrot roots. This compound shows antifungal activity towards ''M. acerina''.

References

External links

Mycocentrosporina acerina

Index Fungorum

USDA ARS Fungal Database
{{DEFAULTSORT:Mycocentrospora Acerina Fungal plant pathogens and diseases Lettuce diseases Vegetable diseases Ascomycota enigmatic taxa