Ex. No. 12                                             Study of foliar, wilt and root rot diseases

Fungi imperfecti, Dust bin fungi, Anamorphic fungi, Asexual fungi, Mitosporic fungi, Residual fungi. Now recent classification point of view they are adopted mostly in Ascomycota and some are in basidiomycota.

Domain: Eukarya, Kingdom: Fungi, Division : : Ascomycota, Sub – division : Pezizomycotina, Class: Dothideomycetes, Order: Pleosporales, Family: Pleosporaceae,  Genus: Cochliobolus

Domain: Eukarya, Kingdom: Fungi, Division : : Ascomycota, Sub – division : Pezizomycotina, Class: Dothideomycetes, Order: Pleosporales, Family: Pleosporaceae,  Genus: Alternaria

Disease name		Causal Organism	Symptoms
Rice blast		Pyricularia oryzae T:Magnaporthe grisea	Spindle shaped spots with grey centre and dark brown margin on leaves, nodes and internodes
Rice brown leaf spot / Sesame leaf spot		Bipolaris oryzae T:Cochliobolus miyabeanus		Brown coloured sesame seed shaped spots on the leaves. Bengal famine (1942-1943)
Banana Sigatoka leaf spot		T: Mycosphaerella musicola Cercospora musae		Initially spots are small, light yellow spots parallel to the side veins of leaves. Later on the spots become enlarge in size and turn brown with light gray centers.
Bhendi Cercospora leaf spot		Cercospora abelmoschi		Black colour powdery patches are appear on underside of the leaves
Sunflower Alternaria blight		Alternaria helianthi                     T: Alternaria is Lewia		Brown colour irregular spots with concentric rings are appear. The concentric rings are due to Alternaric acid – Phytotoxin
Tomato Early blight		Alternaria solani		Brown colour irregular spots with concentric rings are appear
	Banana freckle leaf spot	Phyllostictina musarum		On the leaves numerous, minute dark brown raised spots with a black dots are formed

Vascular Wilts

1.       Fusarium wilt  (Tropical wilt)

Domain: Eukarya, Kingdom: Fungi, Division : : Ascomycota, Sub – division : Pezizomycotina, Class: Sordariomycetes , Order: Hypocreales, Family: Nectriaceae,  Genus: Gibberella (Fusarium sexual stage is Gibberella) (Fusarium oxysporum are not producing sexual stage)

Disease name	Causal Organism	Symptoms
Fusarium wilt of Tomato	Fusarium oxysporum f.sp. lycopersici	Yellowing and Drooping of leaves. Browning and blackening of vascular tissues are appear (Vascular discolouration). Fusarium produces macro conidia, micro conidia and Chlamydospore (resting spore).
Panama wilt of Banana	Fusarium oxysporum f.sp. cubense
Fusarium wilt of cotton	Fusarium oxysporum f.sp. vasinfectum
Foot rot in rice	Fusarium moniliforme

2. Verticillium wilt (Temperate wilt) : Cotton Wilt – Verticiilium dahliae (Tiger stripe symptoms); Tomato Verticillium wilt – Verticillium albo atrum;  Cigar end rot of Banana – Verticillium theobromae

Aganomycetaceae / Mycelia sterlia (In general sterile fungi means Sclerotium producing fungus)

Disease name		Causal Organism	Symptoms
Rice sheath blight		Rhizoctonia solani	Elliptical greenish with irregular blackish brown border spots appear on the leaf sheath near the water level
Pulses root rot	Macrophomina phaseolina Rhizoctonia bataticola		Root portions are decayed. Bark shredding symptoms are appear.
Ground nut collar rot		Sclerotium rolfsii	Reddish brown lesions are appear on the stem near the soil level. Rotten tissues are containing brown mustard shape sclerotia

Anthracnose:  produced sunken spots

Domain: Eukarya, Kingdom: Fungi, Division : : Ascomycota, Sub – division : Pezizomycotina, Class: Sordariomycetes , Order: Glomerales, Family: Glomerellaceae,  Genus: Glomerella (Colletotrichum sexual stage is Glomerella)

Disease name				Causal Organism				Symptoms
Sugarcane red rot		Colletotrichum falcatum				Third or fourth leaf which withers away at the tips along the margins. Reddening of internal tissues with cross white patches. Infected field produce alcoholic odour.
Pulses anthracnose			Colletotrichum lindemuthianum				Sunken brown coloured lesions are appear in the leaves and pods
Fruit rot of chilli	Colletotrichum capsici				A small brown to black coloured spots are appear and spots are having black dots that denotes acervuli.
Mango anthracnose				Colletotrichum  gloeosporioides
Banana anthracnose				Colletorichum musae

Life cycle of Macrophomina phaseolina / Root rot

Kingdom: Fungi ,Division: Eumycota ,Sub – division: Deuteromycotina ,Class: Deuteromycetes ,Order: Aganomycetales

Family: Aganomycetaceae ,Genus: Macrophomina,Species: phaseolina

Disease name: Pulses root rot / Dry root rot

Symptoms: Root portions are decayed. Bark shredding symptoms are appear.

Life cycle: The fungus are having two stages namely Pycnial stage and sclerotial stage.

·         Pycnial stage: Macrophomin phaseolina

·         Sclerotial stage: Rhizoctonia bataticola

·         Sclerotia are black coloured and irregular structures.

·         Infected tissues are having black coloured sclerotia like a coal.

·         The disease is otherwise called charcoal rot. soil borne in nature.

·         In dry and hot conditions the roots are infected

·         The hyphae are inter and intracellular with Septate mycelium.

·         Each Sclerotium size is 100 µ in diameter

·         Later the mycelium are enters to the xylem vessels

Live cycle of Fusarium wilt of banana / Panama wilt of Banana

Kingdom: Fungi ,Division: Eumycota ,Sub – division: Deuteromycotina ,Class: Deuteromycetes ,Order: Moniliales

Family: Tuberculariaceae ,Genus: Fusarium

Species: oxysporum f.sp. cubense

Disease name: Fusarium wilt / Panama wilt of Banana (sudden death)

Symptoms:

1.       Yellowing of leaf blades developing as a band along the margin and spreading towards midrib.

2.       Pseudostem may show longitudinal splitting of outer leaf bases above the soil level

3.       The infected stem smells like rotten fish

Life cycle                                                                      

1.       The fungus produce macro conidia, micro conidia and Chlamydospore

2.       It is a soil borne and producing resting spore Chlamydospore (Hydrochory)

3.       The mycelium are inter and intracellular. Macro conidia are falcate shape, Microconidia are oval and Chlamydospore are globose shaped.

4.       The infection occurs through injured lateral roots

5.       After the entering they are blocking the xylem vessels (formation of gels and tyloses)

6.       Acidic soils are suitable for disease development

7.       They are producing asexual fruiting body is sporodochium

Theories are involved

1.       Tylosis: Vascular vessels mostly xylem are blocking due to wilt fungus

2.       Fusarium fungus are producing Fusaric acid (Vivotoxin)