Articles
MYCOPLASMA OF L-FORMS OF BACTERIA SUSPECTED ETIOLOGIC AGENT OF APRICOT DECLINE (APOPLEXY)
Apoplexy (decline, die-back, chlorotic leaf roll) of apricots is known as one of the most devastating disease of this species, that became a serious problem in many european countries.
Every year the orchards are affected by tremendous crop or trees losses.
There are proofs that the apricot trees disappear prematurely in about 5–15 years.
Thus, in Hungary, 30–40% of the 5–6 year-old orchards were destroyed by apoplexy (Rozsnyay, 1963), and in France about 80% of the losses are caused by this disease (Morvan, 1977). Similar situations were reported from Yugoslavia (Gavrilovic and Paunovic, 1963), and Czechoslovakia (Dvorak, 1963).
In Romania the apoplexy of apricot was first described in 1928 with an estimated loss of 20–30% (Savulescu, 1933) and then observations have showed that about 800 000 apricot trees were destroyed between 1920–1945 (Sonea, 1963).
For many years it was assumed that fungi (Verticillium, Monilia and Cytospora), bacteria and viruses were responsable for apricot decline (Gavrilovic and Paunovic, 1963; Morvan, 1963; Klement, 1973).
A new hypothesis came in 1973 when a group of France workers published the results of an electron microscopic examination of infected apricot trees and Vinca rosea L. connected to diseased apricots with dodder.
In the sieve tubes of the phloem of apricots and periwinkle, large number of structures identical in appearance with mycoplasmas were detected (Morvan et al., 1973). Structures resembling either mycoplasma or L-forms of bacteria were also observed by us and this paper reports the extensive investigations concerning the role of mycoplasma-like organisms or L-forms of bacteria in apricot die-back.
The preliminary results has been presented (Ploaie, 1980).