Mycoplasma plant diseases

Mycoplasma-like diseases in plants are caused by phytoplasmas, which are specialized bacteria lacking a cell wall. These pathogens exclusively inhabit the phloem tissue of host plants, where they interfere with the translocation of sugars and nutrients, leading to severe physiological disruptions throughout the entire plant system.

These pathogens affect a vast range of hosts, including vital crops such as potatoes, tomatoes, fruit trees, and various ornamental plants. Economic losses can be significant due to reduced yield, stunted growth, and the poor market quality of the produce, which often makes affected crops unsuitable for human consumption or processing.

Key symptoms include yellowing (chlorosis) of the leaves, reduction in leaf size, and extreme proliferation of lateral shoots, which gives the plant a bushy or «witches' broom» appearance. Other diagnostic signs are flower malformations, such as greening of petals and sterility, which prevent the formation of seeds or fruits.

Transmission occurs primarily through phloem-feeding insects like leafhoppers, psyllids, and planthoppers. Once an insect acquires the phytoplasma by feeding on an infected plant, it remains a vector for the rest of its life, effectively spreading the disease across the field during the growing season, especially in warm and humid weather conditions.

Effective management strategies focus on preventing transmission by controlling vector populations with appropriate insecticides and eliminating weed hosts that serve as reservoirs. Farmers should prioritize the use of disease-free propagation materials and implement crop rotation to break the cycle of infection, ensuring that primary sources of the pathogen are kept away from susceptible crops.