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Apple Proliferation
(AP)


Apple proliferation is caused by a phytoplasma that ranges in size from 140 to 700 nm and is localized in sieve tubes.

Apple proliferation is found naturally in infected apple and does not seem to survive in other fruit tree species.
It induces variable symptoms, typical for hormonal irregularities:
  • rosettes of dehydrated leaves that crumble easily and roll in a cone
  • breaking of apical dominance and feathering with numerous lateral shoots at a very narrow angle (15°) at the end of summer (´witches broom´)
  • reduction of leaf size, but growth of stipules
  • reduced flowering and phyllody (transformation of white petals into geen leaflets)
  • growth of abundant, but thin, root hairs
  • fructification is often reduced by half and sometimes totally inhibited

In Europe the disease is epidemic in regions with semi-continental climate. It is unknown in North and South America.

Sequence Info (NCBI database)

Isolates in the Vienna Collection

Detection methods



last updated October 8, 2001 by Siegfried.Huss