for class use only
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
B.Sc ( Ag)
COURSE NO. PATH 171
Credit hours 3 (2+1)
DETAILED
THEORY STUDY MATERIAL
INTRODUCTION TO PLANT PATHOGENS
Prepared by
Dr. V. KRISHNA RAO
Professor&Head,Rajendranagar
Dr.R.SARADA JAYALAKSHMI
Professor&Head, Mahanandi
Dr.P.KISHORE VARMA
Assistant Professor,Aswaraopet
Dr.V.DAMODARA NAIDU
UNIVERSITY HEAD
DEPARTMENT OF PLANT PATHOLOGY
ACHARYA N.G.RANGA AGRICULTURAL UNIVERSITY
RAJENDRANAGAR, HYDERABAD- 500 030
2011
, ACHARYA N.G.RANGA AGRICULTURAL UNIVERSITY
Administrative office,Rajendranagar,Hyderabad5 0 0 0 3 0,A.P.INDIA
Phone:040-24015197 (O & F)
Dr.T.YELLAMANDAREDDY Mobile :9989633306
Dean of Agriculture Email:
Grams:’’AGRIVARSITY’’
FOREWORD
Plant Pathology is being taught as a compulsory subject in Under Graduate
Programme and as a specialized subject at the Post G raduate level in the Agricultural
Universities.The importance of Plant pathogens in different crops is well
recognized.The detailed study material for the course PATH 171 is prepared in
accordance with the revised course curriculam as suggested by the IV D eans
committee which helps in easy understanding about the Plant Pathogens,
fungi,bacteria,viruses etc.
The attempt has been made by the authors in the study material to
emphasize the important char acteristics of Plant Pathogens viz; fungi, bacteria,
fastidious vascular bacteria, viruses, viroids,phytoplasmas and spiroplasmas as per the
revised syllabus.
The detailed study material in course No.PATH 171 entitled ‘Introduction to
Plant Pathogens’has been prepared to im part basic knowledge on Plant Pathogens to
Under Graduate students of Agriculture.The information contained in the study
material is appropriate and reliable.The study material consists of 32 lecture notes and
each lecture explains the characteristics of Plant Pathogens.
I congratulate the efforts of Dr.V.Krishna Rao, Dr.R.Sarada Jayalakshmi,
Dr.P.Kishore Varma and Dr.V.Damodara Naidu in compiling the valuable information
in the study material according to the syllabus framed by the Acharya N.G.Ranga
Agricultural University.I feel that this detailed study material provides basic knowledge
and training in identifying and understanding of Plant Pathogens.
( T.YELLAMANDA REDDY )
, DEPARTMENT OF PLANT PATHOLOGY
1. Course No. : PATH 171
2. Course Title : Introduction to Plant Pathogens
3. Credit Hours : 3(2+1)
4.General Objective : To impart knowledge to the students on pathogens
that cause diseases in plants
5.Specific Objectives:
a) Theory :
By the end of the course the students will be able to
i. study different pathogens causing plant diseases
ii. understand the morphological characters and taxonomic keys associated
with the identification of pathogens
b)Practical:
By the end of the practical exercises, the students will be able to
i. identify the plant pathogens
ii. know the modes of transmission of viruses
A) Theory Lecture Outlines :
1.Introduction- importance of plant pathogens - important phytopathogenic
organisms, viz., fungi, bacteria, fastidious vascular bacteria (RLO's),
phytoplasmas (MLO's), spiroplasmas, viruses, viroids, algae and protozoa.
History - contributions of scientis ts - Micheli, Tillet, Prevost, Persoon, Fries,
Smith, Burril, Bejierinck, Stanley, Bawden , Pirie , Doi ,Diener ,Ricketts and
Bove.
2. General characteristics of fungi - fungus - definition - somatic structures -types
of fungal thalli - plasmodium, unicellular and filamentous, eucarpic, holocarpic
mycelium - ectophytic, endophytic, intercellular, intracellular and vascular -
septation in fungi - fungal tissues - plectenchyma (prosenchyma,
pseudoparenchyma)
3. Modifications of mycelium (rhizomorphs, rhiz oids, sclerotium, stroma,
haustoria and appressorium) – Fungal cell, nutrition,groups of fungi based on
nutrition -Reproduction - asexual reproduction - fragmentation,fission, budding
and sporulation
4 Sexual reproduction – planogametic copulation, gametangial contact,
gametangial copulation, spermatization, somatogamy, parasexual cycle -various
life cycle patterns displayed by fungi - haplobiontic and diplobiontic with examples
5.Taxonomy and nomenclature of fungi - Classification of fungi - important
characteristics of divisions -Myxomycota and Eumycota and Sub-divisions -
Mastigomycotina, Zygomycotina, Ascomycotina,Basidiomycotina and
Deuteromycotina
2
, 6. Division - Myxomycota - important characteristics of Class
Plasmodiophoromycetes, Order Plasmodiophorales and Family
Plasmodiophoraceae - differences in the characteristics of Plasmodiophora and
Spongospora and diseases caused by them
7. Division Eumycota - Sub-division Mastigomycotina - important characteristics of
Class Chytridiomycetes, Order Chytridiales and Family Synchytriaceae - diseases
caused and transmitted by Synchytrium
8 Important characteristics of Class Oomycetes, Order Peronosporales and
Family Pythiaceae - Pythium and Phytophthora
9. Family Albuginaceae - disease caused by Albugo Candida - Family
Peronosporaceae - Sclerospora, Peronospora, Peronosclerospora, Plasmopara,
Pseudoperonospora and Bremia (sporangiophore branching and sporangia and
example of a disease caused by each genus)
10. Sub-division Zygomycotina - important characteristics of Class Zygomycetes,
Order Mucorales - diseases caused by Rhizopus
11. Sub-division Ascomycotina - typical life cycle - Pyronema omphalodes
12 Important characteristics of Class Hemiascomycetes, Order Taphrinales,
Family Taphrinaceae - diseases caused by Taphrina deformans and T. maculans
13. Important characteristics of Class Plectomycetes, Order Erysiphales, Family
Erysiphaceae - Erysiphe, Leveitlula, Phyllactinia, Uncinula, Sphaerotheca,
Podosphaera and Microsphaera (characteristics of ascocarps and their conidial
stages)
14. Important characteristics of Class Pyrenomycetes, Order Hypocreales,
Family Clavicipitaceae - diseases caused by Claviceps purpurea
15 Important characteristics of Class Loculoascomycetes, Order pleosporales,
Family Venturiaceae - disease caused by Venturia -inaequalis - Family
Pleosporaceae - diseases caused by Cochliobolus miyabeanus.
16 Important characteristics of Order Myriangiales, Family Myriangiaceae -
diseases caused by Elsinoe awcetti - Important characteristics of Order
Dothideales, Family Dothideaceae - diseases caused by Mycosphaerella
arachidicola, M.berkeleyi and M. musicola - imperfect stages for the genera of
Loculoascomycetes
17 Sub-division - Basidiomycotina - important characteristics of Class
Teliomycetes, Order Uredinales, Family Pucciniaceae – distinguishing
characteristics of Genera - Puccinia, Uromyces and Hemileia – disease
caused by Puccinia graminis tritici, Uromyces appendiculatus and
Hemileia vastatrix.
18. Life cycle of Puccinia graminis tritici - important characteristics of Family
Melampsoraceae Genus Melampsora - disease caused by Melampsora ricini.
3
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
B.Sc ( Ag)
COURSE NO. PATH 171
Credit hours 3 (2+1)
DETAILED
THEORY STUDY MATERIAL
INTRODUCTION TO PLANT PATHOGENS
Prepared by
Dr. V. KRISHNA RAO
Professor&Head,Rajendranagar
Dr.R.SARADA JAYALAKSHMI
Professor&Head, Mahanandi
Dr.P.KISHORE VARMA
Assistant Professor,Aswaraopet
Dr.V.DAMODARA NAIDU
UNIVERSITY HEAD
DEPARTMENT OF PLANT PATHOLOGY
ACHARYA N.G.RANGA AGRICULTURAL UNIVERSITY
RAJENDRANAGAR, HYDERABAD- 500 030
2011
, ACHARYA N.G.RANGA AGRICULTURAL UNIVERSITY
Administrative office,Rajendranagar,Hyderabad5 0 0 0 3 0,A.P.INDIA
Phone:040-24015197 (O & F)
Dr.T.YELLAMANDAREDDY Mobile :9989633306
Dean of Agriculture Email:
Grams:’’AGRIVARSITY’’
FOREWORD
Plant Pathology is being taught as a compulsory subject in Under Graduate
Programme and as a specialized subject at the Post G raduate level in the Agricultural
Universities.The importance of Plant pathogens in different crops is well
recognized.The detailed study material for the course PATH 171 is prepared in
accordance with the revised course curriculam as suggested by the IV D eans
committee which helps in easy understanding about the Plant Pathogens,
fungi,bacteria,viruses etc.
The attempt has been made by the authors in the study material to
emphasize the important char acteristics of Plant Pathogens viz; fungi, bacteria,
fastidious vascular bacteria, viruses, viroids,phytoplasmas and spiroplasmas as per the
revised syllabus.
The detailed study material in course No.PATH 171 entitled ‘Introduction to
Plant Pathogens’has been prepared to im part basic knowledge on Plant Pathogens to
Under Graduate students of Agriculture.The information contained in the study
material is appropriate and reliable.The study material consists of 32 lecture notes and
each lecture explains the characteristics of Plant Pathogens.
I congratulate the efforts of Dr.V.Krishna Rao, Dr.R.Sarada Jayalakshmi,
Dr.P.Kishore Varma and Dr.V.Damodara Naidu in compiling the valuable information
in the study material according to the syllabus framed by the Acharya N.G.Ranga
Agricultural University.I feel that this detailed study material provides basic knowledge
and training in identifying and understanding of Plant Pathogens.
( T.YELLAMANDA REDDY )
, DEPARTMENT OF PLANT PATHOLOGY
1. Course No. : PATH 171
2. Course Title : Introduction to Plant Pathogens
3. Credit Hours : 3(2+1)
4.General Objective : To impart knowledge to the students on pathogens
that cause diseases in plants
5.Specific Objectives:
a) Theory :
By the end of the course the students will be able to
i. study different pathogens causing plant diseases
ii. understand the morphological characters and taxonomic keys associated
with the identification of pathogens
b)Practical:
By the end of the practical exercises, the students will be able to
i. identify the plant pathogens
ii. know the modes of transmission of viruses
A) Theory Lecture Outlines :
1.Introduction- importance of plant pathogens - important phytopathogenic
organisms, viz., fungi, bacteria, fastidious vascular bacteria (RLO's),
phytoplasmas (MLO's), spiroplasmas, viruses, viroids, algae and protozoa.
History - contributions of scientis ts - Micheli, Tillet, Prevost, Persoon, Fries,
Smith, Burril, Bejierinck, Stanley, Bawden , Pirie , Doi ,Diener ,Ricketts and
Bove.
2. General characteristics of fungi - fungus - definition - somatic structures -types
of fungal thalli - plasmodium, unicellular and filamentous, eucarpic, holocarpic
mycelium - ectophytic, endophytic, intercellular, intracellular and vascular -
septation in fungi - fungal tissues - plectenchyma (prosenchyma,
pseudoparenchyma)
3. Modifications of mycelium (rhizomorphs, rhiz oids, sclerotium, stroma,
haustoria and appressorium) – Fungal cell, nutrition,groups of fungi based on
nutrition -Reproduction - asexual reproduction - fragmentation,fission, budding
and sporulation
4 Sexual reproduction – planogametic copulation, gametangial contact,
gametangial copulation, spermatization, somatogamy, parasexual cycle -various
life cycle patterns displayed by fungi - haplobiontic and diplobiontic with examples
5.Taxonomy and nomenclature of fungi - Classification of fungi - important
characteristics of divisions -Myxomycota and Eumycota and Sub-divisions -
Mastigomycotina, Zygomycotina, Ascomycotina,Basidiomycotina and
Deuteromycotina
2
, 6. Division - Myxomycota - important characteristics of Class
Plasmodiophoromycetes, Order Plasmodiophorales and Family
Plasmodiophoraceae - differences in the characteristics of Plasmodiophora and
Spongospora and diseases caused by them
7. Division Eumycota - Sub-division Mastigomycotina - important characteristics of
Class Chytridiomycetes, Order Chytridiales and Family Synchytriaceae - diseases
caused and transmitted by Synchytrium
8 Important characteristics of Class Oomycetes, Order Peronosporales and
Family Pythiaceae - Pythium and Phytophthora
9. Family Albuginaceae - disease caused by Albugo Candida - Family
Peronosporaceae - Sclerospora, Peronospora, Peronosclerospora, Plasmopara,
Pseudoperonospora and Bremia (sporangiophore branching and sporangia and
example of a disease caused by each genus)
10. Sub-division Zygomycotina - important characteristics of Class Zygomycetes,
Order Mucorales - diseases caused by Rhizopus
11. Sub-division Ascomycotina - typical life cycle - Pyronema omphalodes
12 Important characteristics of Class Hemiascomycetes, Order Taphrinales,
Family Taphrinaceae - diseases caused by Taphrina deformans and T. maculans
13. Important characteristics of Class Plectomycetes, Order Erysiphales, Family
Erysiphaceae - Erysiphe, Leveitlula, Phyllactinia, Uncinula, Sphaerotheca,
Podosphaera and Microsphaera (characteristics of ascocarps and their conidial
stages)
14. Important characteristics of Class Pyrenomycetes, Order Hypocreales,
Family Clavicipitaceae - diseases caused by Claviceps purpurea
15 Important characteristics of Class Loculoascomycetes, Order pleosporales,
Family Venturiaceae - disease caused by Venturia -inaequalis - Family
Pleosporaceae - diseases caused by Cochliobolus miyabeanus.
16 Important characteristics of Order Myriangiales, Family Myriangiaceae -
diseases caused by Elsinoe awcetti - Important characteristics of Order
Dothideales, Family Dothideaceae - diseases caused by Mycosphaerella
arachidicola, M.berkeleyi and M. musicola - imperfect stages for the genera of
Loculoascomycetes
17 Sub-division - Basidiomycotina - important characteristics of Class
Teliomycetes, Order Uredinales, Family Pucciniaceae – distinguishing
characteristics of Genera - Puccinia, Uromyces and Hemileia – disease
caused by Puccinia graminis tritici, Uromyces appendiculatus and
Hemileia vastatrix.
18. Life cycle of Puccinia graminis tritici - important characteristics of Family
Melampsoraceae Genus Melampsora - disease caused by Melampsora ricini.
3
