Infection with ‘Candidatus Phytoplasma aurantifolia’ induces significant alterations in nutrient element concentrations across branches and roots of Mexican lime
Abstract
Witches’ broom disease of lime (WBDL) associated with ‘
Candidatus
Phytoplasma aurantifolia’ is a destructive disease affecting Mexican lime in southern Iran. Typical symptoms of the disease including internode shortening, little leaf and witches'-broom. This study was conducted to investigate changes in the concentrations of nutrient elements in the symptomatic branches, asymptomatic branches, and roots of Mexican lime trees infected with ‘
Ca.
P. aurantifolia’, compared to healthy trees in an orchard in Roudan, Hormozgan Province, Iran. Leaf samples were collected from symptomatic branches, asymptomatic branches of infected trees, and healthy trees. In addition, root samples were separately collected from symptomatic and healthy trees. The concentrations of twelve nutrient elements were determined in leaves and roots. The results showed that in symptomatic branches, phosphorus (P), potassium (K), copper (Cu), iron (Fe), chlorine (Cl) and sodium (Na) elements were significantly higher than asymptomatic ones. Conversely, magnesium (Mg), calcium (Ca), manganese (Mn), and boron (B) levels were significantly lower in symptomatic branches. No significant differences were observed in nitrogen (N) and zinc (Zn) levels between symptomatic and asymptomatic leaves. The Na and Cu concentrations showed the most significant increases in symptomatic versus asymptomatic leaves. In the roots, symptomatic lime trees exhibited significantly lower concentrations of N, P, K, Na, Cu, Mn, Fe, and Mg compared to healthy trees; however, no significant differences were found for Cl, B, Zn, and Ca. Overall, these findings suggest that nutritional management, particularly targeting symptomatic trees, could potentially play a role in the management of WBDL in infected orchards.