4. History and Evolution
The genus Alternaria was first recognized by Nees in 1817
In 1836, Berkeley identified the causal fungus on plants belonging to
family Brassicaceae as Macrosporium brassicae Berk. which was
later renamed as Alternaria brassicae (Berk.) Sacc
Elliot studied the taxonomy of Alternaria in detail
Wiltshire pioneered the basic studies of this group of hyphomycetes.
His findings fundamental to the prevailing concepts of Alternaria,
5. Later, Neergaard made an extensive study on the
taxonomy, parasitism and economic significance of
this genus
The morphological variations of Alternaria species
were described by Joly
6. • In India, the first report of Alternaria was made from Pusa
(Bihar) on a herbarium material of Sarson (Brassica sp)
• In U.P. the appearance of Alternaria spp. was noticed by dey
• A comprehensive account of distinguishing characters of the
Indian species of Alternaria has been described by Subramanian
• The characteristic features of a number of Alternaria species are
described in “Dematiaceious Hyphomycetes” and “More
Dematiaceous Hyphomycetes”.
• (Ellis, 1976)
7. • Conidia are produced in single or branched chains on short
conidiophores (Barnett and Hunter, 1998)
• The sexual morphs Lewia linked to Alternaria
(Simmons, 1990)
8. • Analysis of ITS, 18S rDNA, mitochondrial rDNA (mt SSU)
andglyceraldehyde-3-phosphatedehydrogenase (gpd) sequences
revealed close phylogenetic relationships among Alternaria,
Ulocladium, Embellisia, Nymbia and Stemphylium (Teleomorph
Pleospora)
• Stemphylium appears as a sister taxon of the monophyletic clade
Alternaria-Ulocladium-Embellisia-Nymbia
(Pryor and Gilbertson, 2000)
10. Group True fungi
Kingdom Fungi
Sub kingdom Eumycotina
Phylum Fungi imperfecti
Class Hyphomycetes
Order Moniliales
Family Dematiaceae
Genus Alternaria
11. Characterstics of genus AlternariaCharacterstics of genus Alternaria
• Its multi cellular pigmented spores
are produced in chains or in
branching fashions
• The spores are broadest near the
base and taper gradually to an
elongate beak
• Formation of polymorphous conidia
either singly or in short or longer
chains and provided with cross,
longitudinal as well as oblique septa
and having longer or short beaks
12. Host Range
• Alternaria species are important pathogens of a wide variety of crops and weeds.
(Abbas et al.,
1995)
• Alternaria solani that causes serious blight on potato (early blight) and tomato as
well as some Brassicae species and Alternaria brassicae attacks a wide range of
cruciferous plants
(Parry,
1990)
• Alternaria species are also capable of infecting numerous plant species
(Agrios,
1969)
• Including cotton, tobacco, sunflower, onion, apple, carrot, citrus, pear, pistachio,
22. Conidiophores of majority of the
species of Alternaria produce
asexual spores (conidia) measuring
between 160- 200 μm long
Sporulation occurs at a temperature
range of 8-24 ºC, where mature
spores occur after 14-24 hr
Optimum temperatures are
between 16 and 24 ºC where
sporulation time ranges from 12 to
14 hr
Biology and Epidemiology
23. Moisture in the presence of rain, dew or high humidity are
essential for infection and a minimum of 9-18 hr are required
for majority of the species
Relative humidity of 91.5% (at 20 ºC) or higher will result in
the production of large numbers of mature spores in 24 hr
(Humpherson-Jones and Phelps, 1989)
24. Alternaria sect.Alternantherae:conidia and
conidiophores. A–D. A.alternantherae. E–H.
A. perpunctulata. Scale bars = 10 μm
Alternata: conidia and conidiophores. A, N.
A. daucifolii. B, L–M. A. arborescens. C,
H–J. A. alternata. D, O. A. gaisen. E. A.
limoniasperae. F, K. A.tenuissima. G, P. A.
longipes.Scale bars = 10 μm.
25. Alternaria sect. Brassicicola: conidia and conidiophores. A, H. A. brassicicola.
B, I, L–M. A. mimicola. C, G. A. solidaccana. D, J–K. A. conoidea. E–F. A.
septorioides. Scale bars = 10 μm.
Woudenberg et al.,2013
27. Favourable weather conditions
Maximum temperature of 15-29 °C
Minimum temperature of 4-12 °C
Average relative humidity > 60 %
RH I (Morning) > 76 %
RH II (Afternoon) > 25 %
28. Monthly mean of Alternaria spore concentrations
Monthly meteorological factors during the 3-year study period. T mean Mean daily
temperature, T max maximum daily temperature,T min minimum daily temperature, H mean
relative humidity, P rainfall
Escuredo et al., 2010
Dept of Vegetal Biology and Soil Sciences, University of Vigo, Spain
29. Effect of temperature on dry mycelial weight (μg) of fourteen
isolates of Alternaria spp
Effect of temperature on dry mycelial weight (μg) of fourteen
isolates of Alternaria spp
Savitha et al., 2013
Dept of Plant Pathology, UAS,
Raichur
30. Effect of relative humidity on radial growth of fourteen
isolates of A. sesami and A. alternata
Effect of relative humidity on radial growth of fourteen
isolates of A. sesami and A. alternata
Savitha et al., 2013Dept of Plant Pathology, UAS,
Raichur
31. Effect of different pH on the growth of A. alternata isolates (In vitro)
Dept. of Plant Pathology, TNAU, Coimbatore, India
32. Sources of inoculum
The major sources of infected seeds with spores on the seed
coat or the presence of mycelium under the seed coat.
The dissemination of spores occurs by wind, water, tools and
animals.
The fungus can survive in susceptible weeds or perennial
crops
37. Direct penetration of A. brassicicola hyphae through epidermis and stomata
Spreading of A. brassicae hyphae and germ tube through epidermal cells not through stomata
38. Penetration of germ tube of A. brassicae
(highly aggressive) through stomatal opening
Spreading of A. brassicae (least aggressive)
Hyphae over the epidermal cells of leaf
Sharma et al., 2014
Plant Pathology, Indian Agricultural
Research Institute, New Delhi, India.
42. G. B. Pant University of Agriculture and
Technology, Pantnagar (Uttarakhand), India.
43. a) Disease index, b) average number of spots/10 cm2, c) average size of spot
(cm) on leaves of Divya inoculated by isolates grown on the PDA medium on 5,
10 and 15 days after inoculation (DAI)
G. B. Pant University of Agriculture and
Technology, Pantnagar (Uttarakhand), India.
Pathogen aggressiveness of A. brassicae isolates
44. Growth and sporulation of Alternaria sesami on different solid
media
Growth and sporulation of Alternaria sesami on different solid
media
Es = Excellent sporulation; Gs = Good sporulation; Ms = Moderate
sporulation; Ps = Poor sporulation;
Savitha et al., 2013
Dept of Plant Pathology, UAS,
Raichur
45. Pathogenic variation of five groups of isolates of Alternaria
spp. on five sesame genotypes
Pathogenic variation of five groups of isolates of Alternaria
spp. on five sesame genotypes
Savitha et al., 2013Savitha et al., 2013
R : Resistant; MR : Moderately Resistant; MS : Moderately Susceptible; S:Susceptible
Dept of Plant Pathology, UAS,
46. Pathogenic variability in Alternaria mali isolatesPathogenic variability in Alternaria mali isolates
Division of Plant Pathology, SKUAST-
Kashmir, Shalimar, Srinagar, Jammu and
47. RAPD reaction of five Alternaria isolates with
primer GL-A-01, 1Kb DNA ladder was used as
molecular weight size marker
(Nasim et al., 2012)
Institute of Agricultural Sciences, University of
the Punjab, Quaid-e-Azam Campus, Lahore
48. G. B. Pant University of Agriculture and
Technology, Pantnagar (Uttarakhand), India.
49. Primers and their properties for Alternaria species
Eleven PCR fragments with the same size
of 370 bp amplified from the primer pair
Al-f1/Al-r1 in eleven DNA samples of
Alternaria sp. Lane 1 to 4 from A. alternata
and Lane 5 to 11 from lilac leaves infected
with Alternata leaf blight. The left lane is a
100-bp, molecular weight marker.
(Margaret et al., 2011)Dept. of Forestry and Systems, Kookmin University, Seoul, Korea
50. Amplification of the internal transcribed spacer region of the thirty two A. brassicae isolates
collected from the infected cauliflower host from different part of India with the universal primer
ITS1 and ITS4. Lane M: 100 bp ladder
51. Dendrogram representing ITS region of thirty two Alternaria brassicae isolates
(Sharma et al., 2013)
Plant Pathology, Indian Agricultural
Research Institute, New Delhi, India.
52. Electrophoresis showing amplification of Alternaria species using
different RAPD primers
Department of Plant Pathology, UAS, Raichur Karnataka, India
53. • A total of 19 primers were selected after screening of 25 primers for RAPD
analyses.
• All the isolates were clearly amplified with 19 primers and produced
different banding pattern of Alternaria species of each gene of diversity
• The diversity of the Alternaria species was varied from species to species.
Among them some were produced entirely different bands with species
specificity (Alt-90) with OPM-1 at 400bp
• Among all the species, A. sesami produced a species specific band at
400bp with OPM primer but none of the above isolates showed this type of
banding pattern. The species specific band of A. sesami may be
differentiable element among all the bands and sequence pattern of this
species band varied from other Alternaria species
54. Alternaria toxins
• Toxins are classified as host selective (host specific) or non
specific.
• Host-selective toxins (HSTs) are toxic only to host plants of
the fungus that produces the toxin
• Sphingolipid like molecular structure
• Desipeptide- based molecules
• Toxic substances including fucicoccin- like compounds are
also being produced by different pathotypes of Alternaria
57. Effect of purified toxin on seed germination and seedling growth of sesameEffect of purified toxin on seed germination and seedling growth of sesame
(Savitha et al., 2012)(Savitha et al., 2012)
58. Effect of purified toxin on seedling germination and seedling
growth of sorghum and sunflower
Effect of purified toxin on seedling germination and seedling
growth of sorghum and sunflower
Toxin(ppm)
Inhibition of seed
germination over
control (%)
Inhibition of sorghum
seedling growth over
control (%)
Inhibition of
sunflower seedling
growth over control
(%)
Sorghum Sunflower Shoot
length
Root
length
Shoot
length
Root
length
50 3 21 8 8 10 11
100 4 30 26 28 41 43
250 10 44 55 46 50 51
500 42 78 58 48 71 64
1000 87 90 79 80 79 77
2000 97 95 98 99 95 95
CD(P=0.05) 3.46 3.16 3.25 5.53 3.04 2.09
Dept of Plant Pathology, UAS,
Raichur
59. Reactive oxygen species such as super oxide
anion (O2-) and hydrogen peroxide (H2O2)
content in control and infected sesame
leaves from 24 h to 120 h.
Changes in Lipid Peroxidation in control and
infected sesamum leaves from 24 h to 120 h.
Changes in total phenol content in control and
infected sesame leaves from 24 h to 120 h
Biochemical characterization of oxidative
burst during interaction between sesame
response to Alternaria sesame
(Lubaina et al., 2012)
Plant Biochemistry and Molecular Biology Lab, Department of Botany,
University College, Thiruvananthapuram, Kerala, India
61. Reaction of sesamum genotypes to Alternaria leaf blight disease
Department of Plant Pathology
Zonal Agricultural Research Station, Navile,
Shimoga, India.
62. Screening of different sesame varieties in field experiment
against Alternaria leaf spot (Alternaria sesami)
(Marri et al., 2012)
Department of Plant Pathology, Sindh
Agriculture University Tandojam, Pakistan
63. Effect of systemic resistance inducing agents on seed germination,
seedling growth and vigour of sesame, challenged with A. sesami
(Savitha et al., 2012)(Savitha et al., 2012)
Dept of Plant Pathology, UAS,
Raichur
64. In vitro efficacy of different bioagents on mycelial growth
and inhibition of Alternaria carthami
(Taware et al., 2014)
Department of Plant Pathology, Vasantrao Naik Marathwada
Agricultural University,Parbhani, India
65. Effect of biocontrol agents on onion (cv. Pusa Red) seed
germination and vigour
Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi India.
66. Evaluation of plant extracts against purple blotch and
Stemphylium blotch of onion
PB: Purple blotch; SB: Stemphylium blight.
(Mishra and Gupta, 2012)National Horticultural Research and Development
Foundation, Nashik (MS), India
67. Per cent inhibition of mycelial growth of A. helianthi by
different non – systemic fungicides
Per cent inhibition of mycelial growth of A. helianthi by
different non – systemic fungicides
S. No. Fungicides
Per cent inhibition of mycelial growth
Concentrations in percentage
0.1 0.2 0.3 Mean
1 Captan 50.53 65.6 70.49 62.21
2 Chlorothionil 35.79 56.38 68.75 53.64
3 Coc 49.12 65.01 78.47 64.20
4 Iprodione 56.84 71.63 86.46 71.64
5 Mancozeb 53.68 69.83 88.54 70.69
6 Wettable sulphur 3.86 21.63 30.56 18.68
7 Mean 41.64 58.35 70.55
68. Per centage inhibition of mycelial growth of A. helianthi by
different systemic fungicides
Per centage inhibition of mycelial growth of A. helianthi by
different systemic fungicides
S. No. Fungicides Per cent inhibition of mycelial growth
Concentrations in percentage
0.05 0.1 0.15 Mean
1 Benomyl 41.93 48.96 54.04 48.31
2 Bitertnol 61.51 64.58 68.77 64.95
3 Carbendazim 31.27 39.58 51.93 40.93
4 Hexaconazole 73.54 85.77 89.12 82.81
5 Penconazole 56.36 67.71 87.37 70.48
6 Propiconazole 75.26 88.19 89.47 84.31
7 Thiophonate methyl 38.49 48.96 67.37 51.61
8 Tridimefon 55.67 63.89 69.47 63.01
9 Tridemorph 17.53 35.07 46.32 32.97
Mean 50.17 60.30 69.65
69. Evaluation of systemic fungicides on inhibition of spore
germination and radial growth of Alternaria helianthi
(Mesta et al., 2009)(Mesta et al., 2009)
70. Effect of seed treatment, foliar spray and seed treatment and foliar spray with systemic
and non systemic fungicides and biocontrol agents on the disease control of Alternaria
blight of pigeonpea in pot experiment
T1= Bavistin (carbendazim), T2= Blitox-50 (copper oxy chloride), T3= Kavach
(chlorothanlonil), T4= Indofil M-45 (mancozeb),T5= Rovral -50 (iprodione), T6=Propineb
(proximain), T7= T. viride, T8= T. harzianum, T9=Control
Laxman and Singh (2013)
71. In vitro screening of Nutrients (0.1%) on mycelial growth and
spore germination of A. chlamydospora
In vitro screening of Nutrients (0.1%) on mycelial growth and
spore germination of A. chlamydospora
Vanitha et al., 2005Dept. of Plant Pathology, TNAU, Coimbatore, India
76. • Since the first description by Ellis and Martin in 1882 (cited in Sherf and MacNab 1986),
• A. solani, previously known as A. porri f. sp. solani (Neergaard 1945), has been the object
• of intensive studies (Strandberg 1992; Rotem 1994). A. solani belongs to the Fungi
• Imperfecti (Deuteromycotina) in the class Hyphomycetes and order Hyphales (Agrios
• 2005). An Ascomycete fungus, Pleospora solani, has been claimed by Esquivel (1984) as
• the teleomorphic stage of A. solani, but this has not been confirmed by others. A. solani
• belongs to the large-spored group within the genus Alternaria, which is characterized by
• separate conidia borne singly on simple conidiophores (Neergaard 1945). The conidia of
• A. solani are muriform and beaked (Neergaard 1945; Ellis and Gibson 1975). Like other
• members of the genus Alternaria, A. solani has transverse and longitudinal septate
• conidia, multinucleate cells, and dark-coloured (melanized) cells (Rotem 1994). Melanin
• gives protection against adverse environmental conditions including resistance to
• antagonistic microbes and their hydrolytic enzymes (Rotem 1994).
