Introductory Plant Pathology agriculture information – agriinfo.in https://agriinfo.in Sun, 14 Apr 2019 13:11:12 +0000 en-US hourly 1 https://wordpress.org/?v=5.1.1 Flowering Plant Parasites (Phanerogams) https://agriinfo.in/flowering-plant-parasites-phanerogams-1949/ https://agriinfo.in/flowering-plant-parasites-phanerogams-1949/#respond Mon, 07 May 2018 09:45:57 +0000 http://agriinfo.in/index.php/2018/05/07/flowering-plant-parasites-phanerogams/ Flowering Plant Parasites (Phanerogams) Most of the diseases are caused by fungi bacteria and viruses. There are few seeds plants called flowering parasites (Phanerogams) which are parasitic on living plants. Some of these attack roots of the host, while some parasites on stem. Some are devoid of chlorophyll and entirely dependent on their host for […]

The post Flowering Plant Parasites (Phanerogams) appeared first on agriinfo.in.

]]>

Flowering Plant Parasites (Phanerogams)

Most of the diseases are caused by fungi bacteria and viruses. There are few seeds plants called flowering parasites (Phanerogams) which are parasitic on living plants. Some of these attack roots of the host, while some parasites on stem. Some are devoid of chlorophyll and entirely dependent on their host for food supply, while other have chlorophyll and obtain only mineral constituents of food from host by drawing nutrition and water they are called as Holoparasites or complete or total parasite. They have haustoria as absorbing organs, which are sent deep into the vascular bundle of the host to draw nutrients, water and minerals.

Flowering Plant Parasites: There are two types of parasites.

1) Root Parasites:

i) Striga (Partial root parasite)

ii) Orobanche (Complete root parasite) 

2) Stem Parasites:

i) Dodder (Cuscuta) (Complete stem parasite)                                

ii) Loranthus (Partial Stem parasite)

1. Root Parasites:

1. Total or Complete or Holoparasite:

Orobanche (Broom rape or Tokra)
 
It is annual flashy flowering plant growing to height of about 15-50 cm long, yellow or brownish colour and covered by small thin scaly leaves. Flowers appears in the axil of leaves are white or tubular. Fruits appears in the axil of leaves are white or tubular. Fruits are capsule containing and seeds are very small, black in colour remain viable for several years. The hausteria of parasite penetrates into the roots of hosts and draw its nourishment. The growth of the plant is retarded, may die some times. It attacks tobacco, tomato, brinjal, cabbage, cauliflower.

2. Hemi Partial or Semi Root Parasite:

Striga (Witch Weed or Turfula or Talop)
Family Scrophulariaceae

It is a small plant with bright green leaves grows upto height 20-60 cm leaves beers chlorophylls and developed in clusters of 10-20 % host plant. They are obligate parasites therefore, do not obtain all their nutrient from their host root. Flowers are pink in colour, seed are very minute and produce in grate number 5000 to 100000 seeds plant per years. One flower contain 1200-1500 seeds and remains viable upto 12-40 years. Dissemination takes place with rain water, flood, wind and irrigation water. It cause yellowing and wilting of host leaves. It attacks sugarcane jowar, Maize, cereals and millets.

b. Stem Parasites:

1. Total or Complete or Holoparasite:

Cuscuta or dodder (Amarvel, Lovevine) Family cuscutaceae.
Genus – Cuscuta     
It is non chlorophyllous, leaf less parasitic seed plant.

It is yellow pink or orange in colour and attached to the host. They do not bear leaves but bear minute function less scale leaves is produces flower and fruits. Flower are white, pink or yellowish in colour and found in clusters. Seed are form in capsules. A single plant may be produce 3000 seeds.

The first appearances of parasites is noticed as thread like leaf less stem which devoid of green pigment and twine around the stem or leaves of the host. When stem of parasitic plant comes in contact with host, the minute root like organs. i.e. hausteria penetrates into the host and absorbs. When the relation ship of the host is firmly established, the dodder plant looses the contact from soil.

These affect plant get weakened and yield poorly the seeds spread by animals, water and implements and remain viable when condition are unfavorable.

It attacks berseem alfalfa, clover, flax, onion, potato, ornamental and hedge plants.

2. Partial, Semi or Hemi Stem Parasites:

Loranthus
Family- Loranthaceae.
It is a partial parasite of tree trunks and branches with brown stem, dark green leaves but no roots.

1. Stem is thick and flattened of the node, appear in clusters at the point of attack which can be easily spotted on the trees.

2. At the point of attachment with the tree, it shows swellings or tumourous growth where the haustoria are produced. It produces flowers which are long, tabular, greenish, white or red colour and found in clusters. It produces fleshy berries with single seed.

3. The affected host plant becomes stunted in growth and dispersal of seed is mostly through the birds and animals. It attacks mango, citrus, apple, guava.

The post Flowering Plant Parasites (Phanerogams) appeared first on agriinfo.in.

]]>
https://agriinfo.in/flowering-plant-parasites-phanerogams-1949/feed/ 0
Classification of Fungi – up to Genus https://agriinfo.in/classification-of-fungi-up-to-genus-1969/ https://agriinfo.in/classification-of-fungi-up-to-genus-1969/#respond Wed, 04 Apr 2018 10:59:19 +0000 http://agriinfo.in/index.php/2018/04/04/classification-of-fungi-up-to-genus/ Classification of Fungi – up to Genus G.C. Ainsworth ( 1973) and J.Webster (1980) Division: 1) Myxomycota ( Plasmodium or pseudoplasmodium are present): i) Acrasiomycetes ii) Myxomycetes iii) Myxomycetes iv) Plasmodiophoromycetes 2) Eumycota (Absence of Plasmodium or Pseudoplasmodium) : i) Mastigomycotina ii) Zygomycotina iii) Ascomycotina iv) Basidiomycotina v) Deuteromycotina Classes of Sub Division of Mastigomycotina: […]

The post Classification of Fungi – up to Genus appeared first on agriinfo.in.

]]>

Classification of Fungi – up to Genus

G.C. Ainsworth ( 1973) and J.Webster (1980)

Division:

1) Myxomycota ( Plasmodium or pseudoplasmodium are present):

i) Acrasiomycetes
ii) Myxomycetes
iii) Myxomycetes
iv) Plasmodiophoromycetes

2) Eumycota (Absence of Plasmodium or Pseudoplasmodium) :

i) Mastigomycotina
ii) Zygomycotina
iii) Ascomycotina
iv) Basidiomycotina
v) Deuteromycotina

Classes of Sub Division of Mastigomycotina:

i) Chytridiomycetes
Zoospores posteriorly uniflagellate i.e. Whiplash type flagella

ii) Hyphochytridomycetes
Zoosores anteriorly uniflagellate i.e. tinsel type flagella.

iii) Oomycetes:
Zoospores biflagellate flagella i.e. posterior whiplash and anterior tinsel type.

Classification of Class of Oomycetes:

Orders:

i) Saprolegniales
ii) Leptomitales

iii) Lagenidiales

iv) Peronosporales :

There are two types of parasites:
a. Non obligate parasites or Facultative parasites
Family- Pythiaceae
b. Obligate Parasites (Biotrophs)
Family: Albuginaceae
Genus: Albigo

The post Classification of Fungi – up to Genus appeared first on agriinfo.in.

]]>
https://agriinfo.in/classification-of-fungi-up-to-genus-1969/feed/ 0
Reproduction in Fungi https://agriinfo.in/reproduction-in-fungi-1964/ https://agriinfo.in/reproduction-in-fungi-1964/#respond Tue, 03 Apr 2018 06:15:04 +0000 http://agriinfo.in/index.php/2018/04/03/reproduction-in-fungi/ Reproduction in Fungi Reproduction: Reproduction is the formation of new individuals having typical characters of the species fungi reproduce by spores. Spore is an unit of reproductions. Asexual Reproduction: It is also known as somatic or vegetative reproduction and does not involve the union of two nucleus or sex organs. Methods of Asexual Reproduction: 1. […]

The post Reproduction in Fungi appeared first on agriinfo.in.

]]>

Reproduction in Fungi

Reproduction:

Reproduction is the formation of new individuals having typical characters of the species fungi reproduce by spores. Spore is an unit of reproductions.

Asexual Reproduction:

It is also known as somatic or vegetative reproduction and does not involve the union of two nucleus or sex organs.

Methods of Asexual Reproduction:

1. By fragmentation of soma or cell sap or hyphae
2. Binary fission
3. Budding
4. Production of spores

Sexual Reproduction:

Union of two nuclei or gametes of opposite sex a gamete is unisexual. i.e. haploid.

Methods of Sexual Reproduction:

a. Planogamtic Copulation
b. Gametangial Contact
c. Gametangial Copulation
d. Spermatization
e. Somatogamy
f. Heterokaryasis
g. Dikaryotization.

The post Reproduction in Fungi appeared first on agriinfo.in.

]]>
https://agriinfo.in/reproduction-in-fungi-1964/feed/ 0
Classification of Obligate Parasites in Fungi https://agriinfo.in/classification-of-obligate-parasites-in-fungi-1971/ https://agriinfo.in/classification-of-obligate-parasites-in-fungi-1971/#respond Thu, 29 Mar 2018 22:49:25 +0000 http://agriinfo.in/index.php/2018/03/29/classification-of-obligate-parasites-in-fungi/ Classification of Obligate Parasites in Fungi Obligate Parasites are classified in two family Albuginaceae and Fernosporaceae Family Albuginaceae: Genus- Albugo Sporangiospores are club shaped. Sporangia are arranged in Basipetal succession i.e oldest at top and youngest at the bottom. E.g. White rust of Crucifers- Albugo Candida. Classification of Family: Pernosporaceae (Downey Mildew Fungi) Sclerospora Pernospora […]

The post Classification of Obligate Parasites in Fungi appeared first on agriinfo.in.

]]>

Classification of Obligate Parasites in Fungi

Obligate Parasites are classified in two family Albuginaceae and Fernosporaceae

Family Albuginaceae:

Genus- Albugo

Sporangiospores are club shaped. Sporangia are arranged in Basipetal succession i.e oldest at top and youngest at the bottom. E.g. White rust of Crucifers- Albugo Candida.

Classification of Family: Pernosporaceae (Downey Mildew Fungi)

Sclerospora

Pernospora

Plasmopara

Pseudoperonospora

Bremia

Sporangiophore is a long stout hypha, with many upright branches near the end, beraing sporangia at its tips

Sporangiophores are dichitomoulsy branched atacute angles and sporangia are borne on pointed tips.

Sporangiophoresare chotomously branched and sporangia are formed on short sterigmata and irregularly spaced.

Sporangiophores are dichotomously branched and sporangia germinate by means of zoospores.

Sporangiophores are dichotomously branched and tips of branches intocup shapedapophyses wih for sterigamata each bearing sporangia.

E.g. Downey mildew of bajara.-S.graminicola

E.g. Downey mildew of onion-P.destructor

E.g. Downey mildew of grape-P.viticola

E.g. Downey mildew of cucurbits – P.cubensis

E.g. Downey mildew of Lettuce-B.Lactucae.

 

The post Classification of Obligate Parasites in Fungi appeared first on agriinfo.in.

]]>
https://agriinfo.in/classification-of-obligate-parasites-in-fungi-1971/feed/ 0
Concepts of Plant Disease https://agriinfo.in/concepts-of-plant-disease-1939/ https://agriinfo.in/concepts-of-plant-disease-1939/#respond Tue, 06 Mar 2018 16:32:35 +0000 http://agriinfo.in/index.php/2018/03/06/concepts-of-plant-disease/ Concepts of Plant Disease Old: Plant diseases were considered to be a curse and punishment to the people by god for wrongs and since they had committed (religious belief and suspertition). The greak philosopher Theophrastus (300, B.C) was the first to study and write about diseases of trees, cereals and legumes. He wrote a book […]

The post Concepts of Plant Disease appeared first on agriinfo.in.

]]>

Concepts of Plant Disease

Old:

Plant diseases were considered to be a curse and punishment to the people by god for wrongs and since they had committed (religious belief and suspertition).

The greak philosopher Theophrastus (300, B.C) was the first to study and write about diseases of trees, cereals and legumes. He wrote a book named “Enquiry into Plants”. In this book he mentioned his experience about plant diseases. His experience was not based on experimentation. He being unable to explain diseases. He beloved that god controlled the weather that brought diseases. Plant diseases were a manifestation of the worth of God. It is due to religious belief, occulation, superstitions or it is the effect of star moon and bad wind. E.g. Romans actually created a special rust God called Robigo for rust diseases of grain crops. They offered sacrifice of red dogs and sheeps.

This was continued for almost 2000 years after Theophrastus. After invention compound microscope in the mid 1600 scientist enable to see many microorganisms associated with diseased plants and they come to believe that the mildews, rust, and other symptoms observed on plants and microorganisms found on diseased plant. Plant parts were the natural product of diseases than the cause and effect of disease.

Louis Pasteur (1860 -63) provided irrefusable evidence that microorganisms arises only from pre-existing microorganisms and fermentation is a biological phenomenon not just a chemical one. It is accepted that a plant is healthy or normal when it can carry out its physiological functions to the best of its genetic potentials.

1. Cell division, differentiation and development.
2. Absorption of water and nutrients.
3. Translocation of nutrients and water synthesis.
4. Photosynthesis.
5. Translocation and Metabolism or store the photosynthetic products.
6. Production of seed or reproductive organ or survival and multiplication.

Whenever the ability of the cells of a plant or plant part to carryout one or more of these essential functions is interfered either by a pathogenic microorganism or adverse environmental factor. The activities of the cells are altered or inhibited, the cells die or plant become diseased.

Pathogen may Cause Disease in Plant by:

i) Weakening the host by continuously absorbing food from the host cells for their own use.
ii) Killing or disturbing metabolism of host cells through toxins enzymes or growth regulating substances, they secrete.
iii) Blocking the transportation of food, mineral, nutrients and water through the conductive tissues.
iv) Consuming the contents of the host cells upon contact.

The post Concepts of Plant Disease appeared first on agriinfo.in.

]]>
https://agriinfo.in/concepts-of-plant-disease-1939/feed/ 0
Classification of Bacteria or Prokaryotes – Volume II https://agriinfo.in/classification-of-bacteria-or-prokaryotes-volume-ii-1952/ https://agriinfo.in/classification-of-bacteria-or-prokaryotes-volume-ii-1952/#respond Wed, 21 Feb 2018 22:38:29 +0000 http://agriinfo.in/index.php/2018/02/21/classification-of-bacteria-or-prokaryotes-volume-ii/ Classification of Bacteria or Prokaryotes – Volume II The classification of bacteria or prokaryotes (of significance in agriculture and allied fields) given in “Bergey’s Manual of Systematic Bacteriology” is listed as follows. Volume II: Gram Positive Cocci: In this section, 15 diverse genera of bacteria are placed together only because they are non-spore forming, chemo-organotrophic, […]

The post Classification of Bacteria or Prokaryotes – Volume II appeared first on agriinfo.in.

]]>

Classification of Bacteria or Prokaryotes – Volume II

The classification of bacteria or prokaryotes (of significance in agriculture and allied fields) given in “Bergey’s Manual of Systematic Bacteriology” is listed as follows.

Volume II:

Gram Positive Cocci:

In this section, 15 diverse genera of bacteria are placed together only because they are non-spore forming, chemo-organotrophic, Gram – positive cocci. The two important families are i) Deinoccaceae, ( Genus Deinococcus ) ii) Micrococcaceae , ( Genera: Micrococcus, Planococcus and Staphylococcus).  
 
Micrococci are non-motile, aerobic, oxidative harmless saprophytes occurring in soil and fresh water. Planococci are also harmless saprophytes that occur in marine environments. Staphylococci are non-motile facultatively anaerobic parasites. Major pathogenic species is S. aureus, causing wound infections, postoperative infections, food poisoning (Stapholococcai) in humans and mastitis in cattle.  
 
Other genera are Streptococcus, aerotolarant, homofermentative (end product of sugar fermentation is lactic acid only), most are pathogenic to humans and animals. E.g. S. pyogenes causes sore throat, scarlet fever and other human infections, S.mutans, inhabit in human oral cavity and cause dental caries, S. facalis, inhabit in the intestinal tracts humans and animals causing urinary tract infections, S.lactis and S. cremoris are harmless contaminants of milk and dairy products and therefore, widely used as “Starter cultures” in the manufacture of buttermilk and cheeses, S. Pnemoniae, also called Pneumoccus causing lobar pneumonia in humans.

Leuconostocs are harmless saprophytes occurring in grass, silage, grape leaves and spoiled food. They are hetero fermentative, producing CO2 and ethanol or acetic acid in addition to lactic acid and are often used as starter cultures for manufacture of butter, buttermilk, and cheese.

Section 13: Endospore Forming Gram: Positive Rods and Cocci

The important genera under this section are:

i) Bacillus:

Species such as, B. subtilis and B. cereus are mesophilic saprophytes producing exoenzymes that hydrolyze starch and casein, later species can cause a type of food poisoning. B. stenothermophilus, is thermophilic species associated with spoilage of canned foods, B.Polymyxa, has ability of N2 fixation under anaerobic conditions, B.turingiensis and B. popillae are pathogenic to insects, E.g. b.propillae, cause milky disease of Japanese better grub , B.anthracis is the only species of Bacillus that is highly pathogenic to humans and animals causing anthrax disease.

ii) Sporosarcina:

This genus contains cocci that are arranged in tetrads or cubical packets of eight cells. They are widely distributed in fertile soil where they decompose urea.

iii) Clostridium:

Members of the genus are fermentative and same species are important in agriculture. i.e. C. botulinum, causes food poisoning known as botulism, C.tetani, cause tetanus in humans, C.perfringes, cause wound infections (gas gangrene) and food poisoning; C. pasteurianum, mesophile inhabiting in soil and having ability to fix N2.

iv) Desulfatomaculum: Sulfate Reducing Bacteria:
 
Section 14: Non Spore forming Gram-Positive Irregular Shaped Rods:

This section includes heterogenous and variety of bacteria with aerobic or facultative anaerobic nature and, filamentous or non filamentous rods. Some of the important genera are:

a. Corynebacterium:

These are saprophytes occurring in soil and water, animal and human parasites and pathogens, e.g. C.diphtheriae cause diphtheria in humans, also causes diseases in plants.

b. Arthrobacter:

Soil saprophytes with characteristics rod-cocous cycle. i.e. cells in log phase are irregular rods and cell in stationary phase are coccoid.

c. Microbacterium:   
 
These are saprophytes occurring in milk, dairy products and diary equipments.

d. Cellulomonas:

The species are important cellulose decomposer or degrading bacteria.

Section 16: Mycobacteria:

Contain a single Genus Mycobacterium, these are aerobic, slightly curved or straight rods, cell wall contains 90% mycolic acid and are acid-fast in staining reaction. Many species are pathogenic to humans. E.g. M.tuberculosis cause tuberculosis and M.leprae, causes leprosy disease in human.

 

The post Classification of Bacteria or Prokaryotes – Volume II appeared first on agriinfo.in.

]]>
https://agriinfo.in/classification-of-bacteria-or-prokaryotes-volume-ii-1952/feed/ 0
Classes of Sub Division Zygomycotina in Fungi https://agriinfo.in/classes-of-sub-division-zygomycotina-in-fungi-1972/ https://agriinfo.in/classes-of-sub-division-zygomycotina-in-fungi-1972/#respond Sun, 18 Feb 2018 09:31:30 +0000 http://agriinfo.in/index.php/2018/02/18/classes-of-sub-division-zygomycotina-in-fungi/ Classes of Sub Division Zygomycotina in Fungi 1. Class: Zygomycetes   Saprobic or if parasitic or predacious having mycelium in immersed in host tissue. 2. Class: Trichomycetes Associated with arthopods and attached to the cuticle or digestive tract by a holdfast and not immersed in the host tissue. Classification of Family: Mucoraceae Genus- Mucor Genus-Rhizopus Cosmopolitain, […]

The post Classes of Sub Division Zygomycotina in Fungi appeared first on agriinfo.in.

]]>

Classes of Sub Division Zygomycotina in Fungi

1. Class: Zygomycetes 
 Saprobic or if parasitic or predacious having mycelium in immersed in host tissue.

2. Class: Trichomycetes
Associated with arthopods and attached to the cuticle or digestive tract by a holdfast and not immersed in the host tissue.

Classification of Family: Mucoraceae

Genus- Mucor

Genus-Rhizopus

Cosmopolitain, wide spread in soil and on dung and organic substratta. Sporangia are globose and borne on branched and unbranched sporangiophore.

Presence of rhizoid at the base of sporangiophore and stoloniferous habit.

E.g. Mucur mucedo- on dung

E.g. Rhiopus stolonifer- Sweet potato rot

The post Classes of Sub Division Zygomycotina in Fungi appeared first on agriinfo.in.

]]>
https://agriinfo.in/classes-of-sub-division-zygomycotina-in-fungi-1972/feed/ 0
Nomenclature: Binomial System of Nomenclature, Rules of Nomenclature https://agriinfo.in/nomenclature-binomial-system-of-nomenclature-rules-of-nomenclature-1967/ https://agriinfo.in/nomenclature-binomial-system-of-nomenclature-rules-of-nomenclature-1967/#respond Fri, 19 Jan 2018 13:55:11 +0000 http://agriinfo.in/index.php/2018/01/19/nomenclature-binomial-system-of-nomenclature-rules-of-nomenclature/ Nomenclature: Binomial System of Nomenclature, Rules of Nomenclature Taxonomy: Taxonomy is the science that deals with the identification nomenclature and classification of organisms. Nomenclature: It is the system of assigning names to the taxonomic groups or organism according to international rules. Systematics: It is scientific study of organisms with the ultimate object of characterizing and […]

The post Nomenclature: Binomial System of Nomenclature, Rules of Nomenclature appeared first on agriinfo.in.

]]>

Nomenclature: Binomial System of Nomenclature, Rules of Nomenclature

Taxonomy:

Taxonomy is the science that deals with the identification nomenclature and classification of organisms.

Nomenclature:

It is the system of assigning names to the taxonomic groups or organism according to international rules.

Systematics:

It is scientific study of organisms with the ultimate object of characterizing and arranging them in an orderly manner.

By Binomial system of nomenclature was developed by Carlous Von Linnaeus which is now universally used. As per the binomial system the name of organism is composed of two words. i.e. the first word a noun indicating the name of genus in which bacterium has been grouped and the second word is and adjective indicating the name of species. E.g. Erwinia coli, in which Erwinia is the genus and coli is the species.

Rules of Nomenclature:

Following rules should be observed while righting of binomial.

1. The name of the genus should always be capitalized.

2. Species name should not be capitalized.

3. Binomial when written should always be underlined separately; when printed italicized.

4. The name or abbreviated name of the scientist describing the species for first time should be written after binomial. E. g. Pseudomonas syringae Val Hall.

5. If the name is revised, the name of the original describer should be written in bracket followed by the name of the revising scientist. E.g. Xanthomonas compestris pv Oryzae Dye.

6. To avoid confusion the same binomial should not be used to name two different species.

7. The year in which organism was described should be written after the name of the author or scientist.

The post Nomenclature: Binomial System of Nomenclature, Rules of Nomenclature appeared first on agriinfo.in.

]]>
https://agriinfo.in/nomenclature-binomial-system-of-nomenclature-rules-of-nomenclature-1967/feed/ 0
Spore Fruit in Fungi https://agriinfo.in/spore-fruit-in-fungi-1961/ https://agriinfo.in/spore-fruit-in-fungi-1961/#respond Sun, 24 Dec 2017 16:16:31 +0000 http://agriinfo.in/index.php/2017/12/24/spore-fruit-in-fungi/ Spore Fruit in Fungi A spore fruit is an aggregation or collection of spores and spores bearing hyphae, sometimes naked but frequent enclosed in various types of containers or spore cases or receptacles. The spores fruit have a thick wall known as peridium. There are two types of spores fruit based on whether spore fruit […]

The post Spore Fruit in Fungi appeared first on agriinfo.in.

]]>

Spore Fruit in Fungi

A spore fruit is an aggregation or collection of spores and spores bearing hyphae, sometimes naked but frequent enclosed in various types of containers or spore cases or receptacles. The spores fruit have a thick wall known as peridium. There are two types of spores fruit based on whether spore fruit contains the sexual spore or asexual spores.

Spore Fruit:

i) Asexual

a. Sporangium
b. Coremium
c. Sporodochium
d. Sorus
e. Pycnidium
f. Aecium
g. Acervulus
h. Pycnium

ii) Sexual:
 
a. Ascocarps E.g. Cleistothecium
b. Basidiocarps E.g. Puffballs

The post Spore Fruit in Fungi appeared first on agriinfo.in.

]]>
https://agriinfo.in/spore-fruit-in-fungi-1961/feed/ 0
Classification of Bacteria or Prokaryotes – Volume IV https://agriinfo.in/classification-of-bacteria-or-prokaryotes-volume-iv-1954/ https://agriinfo.in/classification-of-bacteria-or-prokaryotes-volume-iv-1954/#respond Fri, 15 Dec 2017 05:56:41 +0000 http://agriinfo.in/index.php/2017/12/15/classification-of-bacteria-or-prokaryotes-volume-iv/ Classification of Bacteria or Prokaryotes – Volume IV The classification of bacteria or prokaryotes (of significance in agriculture and allied fields) given in “Bergey’s Manual of Systematic Bacteriology” is listed as follows. Volume IV: Gram-positive filamentous bacteria of complex morphology. There are soil organisms which are harmless and few are pathogenic to humans, animals and […]

The post Classification of Bacteria or Prokaryotes – Volume IV appeared first on agriinfo.in.

]]>

Classification of Bacteria or Prokaryotes – Volume IV

The classification of bacteria or prokaryotes (of significance in agriculture and allied fields) given in “Bergey’s Manual of Systematic Bacteriology” is listed as follows.

Volume IV:

Gram-positive filamentous bacteria of complex morphology.

There are soil organisms which are harmless and few are pathogenic to humans, animals and plants. In soil, they play important role in degradation of plant and animal residues and some are best producers of antibiotics. Bacteria included in this volume Iv are categorized as follows, under different sections.

a) Nocardiform Actinomycetes (sect.26), the important genera are Nocardia Rhodoccus, Pseudonocardia.

b) Actinomycetes with multicolor sporangia (Sect.27) important genera are: Geodermatophilus, Determatophilus and Frankia, like Rhizobium are highly efficient microacerophilic N2 –fixes that induce stem nodules in woody plants (E.g. Alders) .

c) Streptomycetes and related genera (Sect.29), Streptomycetes are actinomyceous, harmless bacteria occurring in neutral soil at saprophytes. They degrade polymeric organic substances in soil (Starch, pection, and chitin), Streptomyces have the ability to produce great number of variety of antibiotics. Some of the important species of the genus Streptomyces producing antibiotics are listed below:

Species

Antibiotics

S. venezulela

Choloramphenicol

S. dureofaciens

Chlorotetracycline (Auremycin)

S.erythraeus

Erthoromycin

S. fradiae

Neonycin

S.noursei

Nystatin

S. rimosus

Oxyteracycline (Terramycin)

S.griseus

Streptomycin

S.viridifaciens

Tetracycline

 

The post Classification of Bacteria or Prokaryotes – Volume IV appeared first on agriinfo.in.

]]>
https://agriinfo.in/classification-of-bacteria-or-prokaryotes-volume-iv-1954/feed/ 0