Mycosphaerella citri

Mycosphaerella citri is a species of fungus that belongs to the Mycosphaerellaceae family. It is known for causing a disease in citrus plants known as citrus greening disease or citrus canker. This disease is a serious threat to citrus production worldwide.

Taxonomy

The genus Mycosphaerella is a large and complex group of fungi. Mycosphaerella citri is one of the many species within this genus. The taxonomy of Mycosphaerella is complex and has undergone numerous revisions. The genus is currently placed in the family Mycosphaerellaceae, in the order Capnodiales, class Dothideomycetes, phylum Ascomycota, kingdom Fungi.

Description

Mycosphaerella citri is a phytopathogenic fungus, meaning it causes disease in plants. The fungus produces small, black, fruiting bodies known as pycnidia. These pycnidia produce spores that are spread by wind and rain, infecting new plants.

Disease Cycle

The disease cycle of Mycosphaerella citri begins when the spores land on a susceptible host plant. The spores germinate and penetrate the plant tissue, causing infection. The fungus then grows and reproduces within the plant, causing symptoms such as leaf spots, fruit lesions, and cankers. The fungus produces new spores which are released and spread to new host plants.

Management

Management of Mycosphaerella citri and the diseases it causes involves a combination of cultural practices, chemical control, and breeding for resistance. Cultural practices include pruning and removal of infected plant material to reduce the source of inoculum. Chemical control involves the use of fungicides to kill the fungus. Breeding for resistance involves selecting and breeding plants that are naturally resistant to the fungus.

Impact

Mycosphaerella citri has a significant impact on citrus production worldwide. The disease it causes, citrus greening disease, can lead to significant yield losses and even death of the citrus tree. The disease is particularly problematic in regions where citrus is grown commercially, such as Florida, California, and Brazil.