A large group of bacteria cause disease in plants. they have specific characteristics and structure. There are different mechanism by which bacteria affect the plant and cause disease symptom. It is generally survive in soil and dead and decay organic matters and spread by water, agricultural implements, propagating materials, insects and humans. Hence, management practices are designed accordingly. Crop rotation, field sanitation, disinfestation of agricultural implements, use of disease free or resistant varieties and use of antibiotics are few of them.
A large group of bacteria cause disease in plants. they have specific characteristics and structure. There are different mechanism by which bacteria affect the plant and cause disease symptom. It is generally survive in soil and dead and decay organic matters and spread by water, agricultural implements, propagating materials, insects and humans. Hence, management practices are designed accordingly. Crop rotation, field sanitation, disinfestation of agricultural implements, use of disease free or resistant varieties and use of antibiotics are few of them.
Effect of environment and nutrition on plant disease developmentparnavi kadam
BRIEF AND PRECISE POINTS ON PLANT DISEASE DEVELOPMENT. IT MOSTLY FOCUSES ON HOW THE FACTORS AFFECT THE MICROBES AND THEN THEIR MICROBIAL EFFECT ON DISEASE DEVELOPMENT.
Introduction to the science of plant pathology, its objectives, scope and historical background. Classification of plant diseases, symptoms, signs, and related terminology. Parasitic causes of plant diseases (fungi, bacteria, viruses, phytoplasma, protozoa, algae and flowering parasitic plants), their characteristics and classification. Non-parasitic causes of plant diseases. Infection process. Survival and dispersal of plant pathogens. Plant disease epidemiology, forecasting and disease assessment. Principles and methods of plant disease management. Integrated plant disease management.
Plant viruses are transmitted from plant to plant in a number of ways.
Transmission of viruses by vegetative propagation.
Mechanical transmission of viruses through sap.
Transmission of viruses by seed.
Transmission of viruses by Pollen.
Transmission of viruses by dodder.
Transmission by vectors.
Effect of environment and nutrition on plant disease developmentparnavi kadam
BRIEF AND PRECISE POINTS ON PLANT DISEASE DEVELOPMENT. IT MOSTLY FOCUSES ON HOW THE FACTORS AFFECT THE MICROBES AND THEN THEIR MICROBIAL EFFECT ON DISEASE DEVELOPMENT.
Introduction to the science of plant pathology, its objectives, scope and historical background. Classification of plant diseases, symptoms, signs, and related terminology. Parasitic causes of plant diseases (fungi, bacteria, viruses, phytoplasma, protozoa, algae and flowering parasitic plants), their characteristics and classification. Non-parasitic causes of plant diseases. Infection process. Survival and dispersal of plant pathogens. Plant disease epidemiology, forecasting and disease assessment. Principles and methods of plant disease management. Integrated plant disease management.
Plant viruses are transmitted from plant to plant in a number of ways.
Transmission of viruses by vegetative propagation.
Mechanical transmission of viruses through sap.
Transmission of viruses by seed.
Transmission of viruses by Pollen.
Transmission of viruses by dodder.
Transmission by vectors.
What is bacteria?(Structures Present in Bacteria And their Functions | Prokar...sehriqayyum
Explains what bacteria is and where it exists.
A key feature of nearly all prokaryotic cells is the cell wall, which maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment.
The cell walls of prokaryotes differ in structure from those of eukaryotes. In eukaryotes that have cell walls, such as plants and fungi, the walls are usually made of cellulose or chitin. In contrast, most bacterial cell walls contain peptidoglycan, a polymer composed of modified sugars cross-linked by short polypeptides.
Using a technique called the Gram stain, developed by the 19th-century Danish physician Hans Christian Gram, scientists can categorize many bacterial species according to differences in cell wall composition.
Gram-positive bacteria have simpler walls with a relatively large amount of peptidoglycan. Gram-negative bacteria have less peptidoglycan
and are structurally more complex, with an outer membrane
that contains lipopolysaccharides (carbohydrates bonded
to lipids).
LEARN ABOUT:
- Bacteria
- The number of viruses on earth is staggering
- Pathogenic yeasts
- Helminths
- Harnessing bacteria
- Microbes on the tree of life
- Living and working together
- Archaea
- Protozoa
LEARN ABOUT:
- Bacteria
- The number of viruses on earth is staggering
- Pathogenic yeasts
- Helminths
- Harnessing bacteria
- Microbes on the tree of life
- Living and working together
- Archaea
- Protozoa
The bacterial flagellum has three main parts (the motor, hook, and filament) that are themselves composed of 42 different kinds of proteins.The cells of prokaryotes are simpler than those of eukaryotes
in both their internal structure and the physical arrangement
of their DNA. The genome of a prokaryote is structurally different from
a eukaryotic genome and in most cases has considerably less DNA. Prokaryotes generally have circular chromosomes, whereas eukaryotes have linear chromosomes.
Ultrastructure and characterstic features of bacteria.Archana Shaw
Ultrastructure and characterstic features of bacteria: BACTERIA AS A MODEL ORGANISM
THIS WAS MY PRESENTATION TOPIC IN CLASS. THOUGHT OF SHARING IT AND HOPE IT HELPS.
Bacteria are unicellular, procaryotic microorganisms which have diverse shape size and structures. Bacteria are found almost everywhere on Earth. Even the human body is full of bacteria, and in fact is estimated to contain more bacterial cells than human cells. Most bacteria in the body are harmless, and some are even helpful. A relatively small number of species cause disease.
Bacteria are small single-celled organisms. Bacteria are found almost everywhere on Earth and are vital to the planet's ecosystems. Some species can live under extreme conditions of temperature and pressure. The human body is full of bacteria, and in fact is estimated to contain more bacterial cells than human cells.
Definition, Characteristics, Nutrition, Special Structures, Reproduction, Nam...Dr. Rajbir Singh
This Lecture Include the Definition, Main Characteristics, Nutrition, Special Structures, Reproduction (Asexual and Sexual), Naming and Classification (Old and New)of Fungi.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
The French Revolution Class 9 Study Material pdf free download
Plant pathogenic bacteria
1. PLANT PATHOGENIC BACTERIA
DR. RAJBIR SINGH
Associate Professor
Department of Plant Pathology
Gochar Mahavidyalaya (Post Graduate College)
Rampur Maiharan, Saharanpur (UP), India
Affiliated to: CCS University, Meerut (UP), India
Email: rajbirsingh2810@gmail.com
Note: All images have been taken form internet. I am grateful to all author of images.
2. History of Bacteria
• Anton van Leeuwenhoek (1632-1723) – ‘Father of Microbiology’. In 1676 observed bacteria
and Protozoa under microscope.
• Hooke (1820)- Under compound microscope seen bacteria and called “Small Microscopic
Species/Infusorial Animacutes”.
• Ehrenberg (1828)- He gave the term ‘Bacterium’.
• Louis Pasteur (1822-1895)- ‘Father of Bacteriology’. He gave terms: Sterlization, Fermentation,
Pasteurization, Immunization. He developed Rabies Vaccine & established Pasteur Institute.
• Koch’s Postulates (1843-1910)- ‘Father of Bacteriological Techniques’. In 1882 gave postulates.
• T. J. Burril (1878-82)- Reported first time that a plant disease ‘Fire Blight of Pear & Peach’ is
caused by Bcateria.
• Joseph Lister (1827-1912)- Give “Antiseptic and Aseptic Theory”.
• Winogradsky (1890)- ‘Father of Soil Bacteriology’. He describe NO2 & NO3 functioning.
4. Description of different parts of bacterial cell
(1). Cell Envelope
• It is outer covering & has 3 components— glycocalyx, cell wall
and cell membrane.
(i). Glycocalyx (Mucilage Sheath):
• Outermost mucilage layer & consists of non-cellulosic
polysaccharides with or without proteins.
• It may occur in the form of loose sheath then it is called ‘Slime
layer’. If thick and tough, the mucilage covering is called
‘Capsule’.
Functions:
• (a) Prevention of desiccation,
• (b) Protection from phagocytes, toxic chemicals and drugs & viruses,
• (e) Attachment,
• (f) Immunogenicity and Virulence.
5. (2). Cell Wall
• It is rigid solid covering , provides shape and structural support.
• In Gram + ve is 8-12 nm & in gram – ve 20-80 nm thick.
• It consists of lipopolysaccharides, lipids and proteins.
• Inner wall layer of Gram -ve is made up of pepidoglycan, proteins, non-
cellulosic carbohydrates, lipids, amino acids, etc.
• Peptidoglycan known as murein or mucopeptide. Peptidoglycan consists
of long glycan strands formed of repeating units of N-acetyl glucosamine
(NAG) and N-acetyl muranic acid (NAM). They are cross linked by small
peptide chains.
• Peptidoglycan constitutes 70-80% of wall in Gram +ve bacteria. Lipid
content is little. 10-20% of wall in Gram -ve bacteria is formed of
peptidoglycan. Lipid content is 20-30%.
6. (3). Plasma Membrane
• It is selectively permeable covering of the cytoplasm.
• Plasma membrane or plasma lemma has a structure
similar to that of a typical membrane.
• It is made of a phospholipid bilayer with proteins of
various types.
• It holds receptor molecules for detection and
responding to different chemicals of the surroundings
• It is metabolically active as it takes part in respiration,
synthesis of lipids and cell wall components.
7. i. Flagella:
• Flagella are filamentous protein structures
attached to the cell surface.
• It provides the swimming movement.
Movement - 50 NM or 0.001/Second.
• Size is about 20 nm (0.02 µm) in diameter and
1-7µm in length.
• Made of 3 parts— basal body, hook and
filament.
• It is made up of protein called flagellin.
8. ii. Pili and Fimbriae
• longer, fewer and thicker tubular outgrowths which develop
in response to F+ or fertility factor in Gram +ve bacteria.
• Made up of protein pilin.
• Helpful in attaching to recipient cell and forming conjugation
tube. So called Sex Pili.
• Diameter is 3-10 nm while length is 0.5-1.5 µm.
• Some fimbriae cause agglutination of RBC. They also help in
mutual clinging of bacteria.
•
9. (IV). Cytoplasm:
• It is crystallo-colloidal complex excluding its nucleoid.
• Cytoplasm is granular due to presence of a large number of ribosomes.
Various structures present in cytoplasm are as follows:
(i) Mesosome:
• It is a characteristic circular to villi form specialisation of cell membrane of
bacteria that develops as an in growth from the plasma membrane
• It takes part in replication of nucleoid by providing points of attachment to
the replicated ones.
• At the time of cell division, plasma membrane grows in the region wher
that most probably it provides membranes for rapid elongation.
• It contains respiratory enzymes and is, therefore, often called chondrioid.
10. (ii) Ribosomes:
• They are small membrane less, sub-microscopic ribo-
nucleoprotein entities having a size of 20 nm x 14-15
nm. Fixed ribosomes are attached to the plasma
membrane.
• Each ribosome has two subunits, larger 50S and
smaller 30S.
• Ribosomes take part in protein synthesis. Free or
matrix ribosomes synthesize proteins for intracellular
use while fixed ribosomes synthesize proteins for
transport to outside.
• Ribosomes generally occur in helical groups called
polyribosomes or polysomes.
11. (iii). Nucleoid:
• It represents the genetic material of
prokaryotes.
• Nucleoid consists of a single circular strand of
DNA duplex which is supercoiled with the help
of RNA and polyamines to form a nearly oval or
spherical complex.
• The folding is 250-700 times.
• Polyamines or nucleoid proteins are different
from histone proteins.
• DNA of prokaryotes is considered naked
because of its non-association with histone pro-
teins and absence of nuclear envelope around it.
12. (iv). Plasmids
• They are self-replicating, extra chromosomal
segments of double stranded, circular, naked
DNA. Plasmids provide unique phenotypic
characters to bacteria. They are independent
of main nucleoid.
• Some of them contain important genes like
fertility factor, nif genes, resistance factors and
colicinogenic factors. Plasmids which can get
associated temporarily with nucleoid are
known as episomes.
13. (v). Chromatophores:
• They are internal membrane systems of
photosynthetic forms which possess
photosynthetic pigments. In purple bacteria
the membranes are typical while in green
bacteria they are non-unit, non-lipid and
proteinaceous. Chromatophores of green
algae are called chromosomes. Photosynthetic
pigments are bacteriochlorophyll,
bacteriophaeophytin (bacterioviridin) and
carotenoids.
14. (iv). Inclusion Bodies:
• The inclusion bodies may occur freely inside
the cytoplasm or covered by 2-4 nm thick non-
lipids, non-unit protein membrane.
Types of Inclusion Bodies: 3 types base on nature
1. Gas vacuoles
2. Inorganic inclusions
3. Food reserve
15. Morphology of Bacteria
Morphology of bacteria include- size, shape, grouping
or aggregation of cells, flagellation and ultra structure
of bacteria.
• Size of bacteria-
Generally diameter of bacteria is – 0.35 – 0.5 µm
Length is – 1-5 µm
• Shape of bacteria- three type of shapes:
1. Spherical bacteria
2. Straight rod shaped bacteria
3. Bent or curved shaped bacteria
16. 1. Spherical bacteria
Spherical bacteria also known as Coccus pl. cocci. These bacteria are
oval, ellipsoidal shape but some may be pear shaped, bean shaped.
There diameter is about 0.2 – 4 µm. Base on their aggregation they
are of 6 types:
• Monococcus: A bacteria that lives as one cell. Exp. Micrococcus bicolor.
• Diplococcus: is a cocci that is found in pairs. Exp. Diplococcus pneumoniae.
• Streptococcus: the bacteria form long chains. Exp. Streptococcus lactis.
• Tetrad: A group of four cells forming a flat square. Exp. Micrococcus roseus.
• Sarcina: is a cube-like group of eight cocci. Exp. Sarcina lutea.
• Staphylococcus: bacteria form an irregular, grape-like cluster. Exp.
Staphylococcus aureus.
•
17.
18. 2. Straight Rod Shaped Bacteria
Rod shaped bacteria also known as Bacillus pl. bacilli. These bacteria are straight and
cylindrical like a rod with ends being flat rounded or cigar shaped. On the base of
aggregation they are following 4 types:
(1). Microbacillus: In this a rod shaped bacterium divide into two cells
and each divided bacterium live separate. Exp. Microbacterium.
(2). Diplobacillus: In this a rod shaped bacterium divide into two cells
and both divided bacterium attached to each other. Exp.
Diplobacterium.
(3). Streptobacillus: This a rod shaped bacterium divide and make a
chain of divided bacteria. Exp. Streptothrix.
(4). Pailsade: In this rod shaped bacteria live in group and look like pole .
Exp. Corynebacterium diptheriae
19.
20. 3. Bent or Curved Rod Shaped Bacteria
These are two types:
1. Vibrio: These bacteria are comma ( , ) shaped. Exp.
Vibrio, Bdellovibrio.
2. Spiral or Helix or Spirillum: Spirllum is made of Greek
word Spira which meaning is Coil. These bacteria are
rigid spiral forms. Exp. Spirillum, Campylobacter.
21. Flagellation in Bacteria
The various forms of flagellation are as follows:
(a) Atrichous: Flagella absent.
(b) Monotrichous: A single flagellum occurs sat or near one
end of bacterium.
(c) Amphitrichous: A flagellum at each of the two ends.
(d) Lophotrichous: A group or tuft of flagella is found only
at one end.
(e) Cephalotrichous: A tuft or group of flagella occurs at
each of the two ends or poles.
(f) Peritrichous: A number of flagella are distributed all
over the surface.
22.
23. Classification of Plant Pathogenic Bacteria
• According to David H. Bergey’s Manual of Determinative
Bacteriology (Last vol. published in 1994)
• Bergey divided plant pathogenic bacteria in 4 divisions and 7
classes.
Kingdom: Prokaryote
Division- I- Gracilicutes (gram – ve bacteria)
Class- I- Scotobacteria
Class- II- Anoxyphytobacteria
Class- III- Oxyphytobacteria
24. Division –II- Firmicutes (Gram +ve bacteria)
Class –I- Firmibacteria
Class –II- Thallobacteria
Division –III- Tenricutes (Bacteria- lacking cell wall)
Class- I- Mollicutes
Division – IV – Mendosicutes (Bacteria with abnormal
cell wall)
Class – I- Archobacteria
25. Asexual Reproduction in Bacteria
Vegetative or Asexual reproduction in bacteria
is by following methods:
1. BY Binary fission
2. By Endospores
3. By Cysts
4. By Fragmentation
5. By Arthospores
6. By Conidia
26. 1. Binary Fission: Most bacteria rely on binary
fission for propagation. In this a cell just needs to grow to
twice its starting size and then split in two.
27. 2. Endospore: Spores are formed during unfavorable
environmental conditions. As the spores are formed within the
cell, they are called endospores. Only one spore is formed in a
bacterial cell. On germination, it gives rise to a bacterial cell.
28. 3. Cysts: Cysts are formed by the deposition of
additional layer around the mother wall. These are the
resting structure and during favorable conditions they
again behave as the mother. Exp. Azotobacter.
29. 4. Fragmentation: In this, body of a bacterium
break in several parts or fragments and each such
individual fragment develop into a bacterium.