Bacteria are the microscopic, unicellular, prokaryotic organism devoid of chlorophyll and multiply mostly by binary fission.

Plant Pathogenic Bacteria Characteristics

• Microscopic, unicellular, prokaryotic and chlorophyllous

• Mostly are gram negative

• Mostly are rod shaped

• Almost all are aerobic

• All are motile

• Very sensitive to sunlight and desication.

Economic important of plant pathogenic bacteria

• Yield loss about $49.6 billion(1976)

• Control measures are less effective and cost is high

• Used as genetic resources and in the field of Biotechnology (Agrobacterium)

• Used as biological controlling agents

• Used as industrial components like in cosmetic surgery

Bacterial structure

Bacterial cell is composed of

• Cell membrane

• Cell wall

• Capsule

• Flagella

• Pilli

• Cytoplasm

• DNA

• Plasmid

• Ribosomes

Bacterial Growth Curve

Bacterial growth curve has 4 phases

• Leg phase

• Logarithmic phase

• Stationary phase

• Decline phase

Reproduction of Bacteria

A.Asexual reproduction

i)Binary fission

ii)Budding

iii) Fragmentation

iv)Spore formation

B.Sexual reproduction

i) Conjugation

ii) Transformation

iii) Transduction