New peach disease in Egypt caused by Bacillus pumilus
In Egypt, during the last few years, an unusual bacterial disease of Balady peach fruits and leaves (Prunus persicae cv. Balady) became common in El-Minia Governorate. The disease is now widespread in all local peach orchards and causes heavy yield losses. Symptoms are characterized by light brown blotch which covers large area of immature fruit surface. Some brown spots also occur on the leaves. A bacterium was consistently isolated from naturally infected tissues and from inoculated plants. The isolated bacterium was identified as Bacillus pumilus according to its physiological and biochemical properties, pathogenicity, electron microscopy and fatty acid composition analysis. In laboratory conditions, this pathogen can cause soft rots on many fruits species (peach, plum, apple, pear), on garlic cloves and plant tissues (slices of potato tuber, carrot) which suggest that B. pumilus is a wound parasite able of inducing softening of fruits and vegetables under relatively high humidity. It was observed that B. pumilus produced pectic enzymes (endopolygalacturonase and endopectin lyase) in vivo and in vitro. In addition, B. pumilus was able to infect some unwounded fruits of peach and pear, possibly through lenticels. This is the first report of B. pumilus causing a disease on peach in Egypt.
Saleh, O.I.; Huang, P.Y., Huang, J.S. (1997) Bacillus pumilus, the cause of bacterial blotch of immature Balady peach in Egypt.
Journal of Phytopathology, 145(10), 447-453.