Stubborn Disease of Citrus Caused by Spiroplasma Citri: A Short Note

Abstract

Citrus fruit is considered a very nutritious and delicious diet. Citrus consists of lemon, oranges, mandarin, and grapefruit which have economic value in the world. Significant losses occur in citrus due to numerous diseases. Among various diseases, citrus trees are seriously affected by a phytopathogenic mollicute Spiroplasma citri which causes stubborn disease. S. citri is transovarially transmitted by several leafhopper species. Symptoms include smaller and cupped leaves, small size, crook fruits with aborted seeds. Moreover, irregularity on the fruits such as different sizes, shapes, and typically lighter, smaller fruits than its healthy counterpart has also been observed. The affected fruits often drop before maturity. The color inversion is often seen with the stylar end remaining green and the peduncle end showing color. Various molecular and biochemical tests are conducted to identify S. citri. Under in-vitro conditions, S. citri grows on SP4 media where a fried egg-like shaped colony is observed. Keeping the importance of the stubborn citrus disease, the present short note briefly described the symptomology, detection, transmission, and management.