Phytoplasma titer in diseased lavender is not correlated to lavender tolerance to stolbur phytoplasma

摘要

Yellow decline of lavender is associated with stolbur phytoplasma. It is an economically important disease in south-eastern France, and there is no curative control method. In the past few years, susceptible and tolerant lavenders (Lavandula spp.) or lavandins (Lavandula latifolia x lavandula angustifolia) were proposed as disease management strategy to growers. However, the bases of tolerance were unknown. In order to establish these possible bases, we compared the titers of stolbur phytoplasma in the leaves and shoots of different lavenders and lavandins, either sensitive or tolerant. Results showed that symptom severity was not correlated to the tolerance status of all cultivars tested, and that symptom severity was not correlated to the phytoplasma titer.