Fire blight disease

Bacterial Plant Disease caused by Erwinia amylovora

1. Fire Blight Disease Bacterial Plant Disease Presented By: Ruqiya Sania Roll. No: 177514 Dept. of Microbiology

2. Fire blight is a contagious disease affecting apple, pears and some other members of family Rosacea It is caused by E.amylovora Under optimal conditions, it can destroy an entire orchard in a single growing season and is Gram- negative bacterium. Fire Blight

3. In early 1800s, E. amylovora was used as a first bacterium to indicated the plant disease Today it can currently be found in Canada, USA, Africa and Egypt In 1950s it was first introduced into Northern Europe During 1950s-1960s E. amylovora had spread through much of Northern Europe History

4. In 1980s, it had been found in Eastern Mediterranean In 1990s, it was discovered in Germany From the years 1995-1996 cases of fire blight had begun to reported in countries such as Hungry, Romania, Northern Italy and Spain History

5. Honeybees and other insects, birds, rain and wind can transmit the bacteria to susceptible tissue Injured tissue is also highly susceptible to infection Hail storm can infect the entire orchard in a few minutes Dissemination

6. The bacterium enter the plant through open stomata and produce a viscous exudate The pathogen spread through from the point of infection via the plant’s vascular system. It typically enter into its host xylem and cortical parenchyma Dissemination

7. Down pour or water sprinkling, bugs and wings animals, other tainted plants and unclean cultivated instruments Fly Delia platura has been observed visiting fire blight wound to feed but was unconfirmed as an effective vector Aerosols are also suspected in playing a role in its transmission Dissemination

8. Symptoms on blossoms include water soaking of floral receptacle, ovary and peduncles A dull, grey-green appearance at 1-2 weeks after petal fall & tissues become black in colour A “ shepherd’s crook” can be seen when the tip of the shoot wilts Symptoms

9. Pathogenicity depends on production of siderophore desferrioxamine, metal proteases, plasmids and histone like proteins Variations in the synthesis of EPS and mechanism of type III secretion system and its associated proteins Motility is another major virulence factor Pathogenesis

10. Select the resistant varieties Avoid heavy pruning Avoid planting close to wild plants Prune off infected branches Dip pruning shears into a 10% alcohol or bleach solution between each cut to avoid transmission Use of Streptomycel lydicus Use of Organocide ® Plant Doctor Treatment

11. Causative agent Host Symptoms Additional Features Erwinia amylovora Apple & Pear Blossoms appear , water soaked and shrivel. Spread to leaves and stems, causing rapid die back First plant disease proved to be caused by a bacterium Bacterial disease of Plant

12. Domain Bacteria Phylum Proteobacteria Class Order Enterobacterales Family Erwiniaceace Genus Erwinia Specie amylovora Domain Bacteria Phylum Proteobacteria Class Order Enterobacterales Family Erwiniaceace Genus Erwinia Specie amylovora Scientific Classification

13. (a) (a) E. amylovora on apples (b) (b) E.amylovora on pears

14. Thank You