Spiroplasma disease

Spiroplasma phoeniceum is a plant pathogen belonging to the class Mollicutes, known primarily for causing severe yellowing and stunting diseases in various ornamental and agricultural plants. Unlike true bacteria, these organisms lack a cell wall and are obligate parasites that reside and multiply within the sieve tubes of the plant's phloem, directly disrupting the plant's vascular system.

The primary host for Spiroplasma phoeniceum is the periwinkle (Catharanthus roseus), which is highly susceptible to this infection. However, the pathogen's ability to infect diverse plant species poses a risk to botanical gardens and horticultural sectors. By colonizing the phloem, the organism hijacks the transport of sugars and nutrients, leading to systemic physiological collapse.

Clinical signs of infection are typically systemic and progressive. Initial symptoms include chlorosis (yellowing) of the younger leaves, followed by significant reduction in leaf size and stunted internode elongation. In advanced stages, plants exhibit a "witches' broom" appearance, failure to produce viable seeds or flowers, and eventually, the complete decline and death of the plant tissue.

The transmission of this disease is exclusively vector-mediated. Leafhoppers (family Cicadellidae) act as the principal vectors, acquiring the bacteria while feeding on infected phloem sap. After a latent period within the insect, where the pathogen colonizes the salivary glands, the vector can transmit the disease to healthy plants through subsequent feeding cycles, making insect management critical to disease control.

• Monitor and eliminate infected host plants promptly.
• Control populations of leafhopper vectors with systemic insecticides.
• Implement physical barriers such as insect-proof nets in greenhouses.
• Utilize certified disease-free propagation material.
• Maintain weed control to reduce alternate host reservoirs for the pathogen.