Practical 5 - Higher fungi (Ascomycota)

Penicillium sp.

Penicillium

AIM

To observe pure cultures of Penicillium sp., Chaetomium sp., Fusarium sp., and Curvularia sp.
To examine and record the plant disease symptoms specimens caused by fungi of phylum Ascomycota
To examine and record fungal structures from the slides displayed
To observe the disease cycles of various Ascomycetes

INTRO

Ascomycota, also called sac fungi, a phylum of fungi (kingdom Fungi) characterized by a saclike structure, the ascus, which contains four to eight ascospores in the sexual stage.

A) FUNGAL CULTURE

PROCEDURE

Preparing slide from fungal culture Ascomycota.

Penicillium sp., Chaetomium sp., Fusarium sp., and Curvularia sp., has been provided.
Firstly, clean slide and cover slide were prepared.
Inoculation needle was used to transfer fungal specimen on the slide and was sterilled with alcohol before used.
A small drop of lactophenol were put to cover the area below cover slip.
A slide slowly put above spirit lamp to remove trapped bubbles, concentrate and reduce moisture. Tissue paper was used for absorption if the lactophenol sip out from below the cover slip.

Preparing slide from fungal culture (Ascomycota)

Chaetomium sp.

Fusarium sp.

Curvularia sp.

B) PLANT DISEASE SPECIMENS

i) Powdery mildew of rubber

Caused by Oidium heveae
Host : Rubber
Infects young leaves of rubber causing massive leaf fall
Fungus also lives on mature leaves throughout the year

Image result for powdery mildew of rubber

Powdery mildew on rubber

ii) False smut of padi

Class : Pyrenomycetes

Order : Clavicipitales

Caused by Ustilaginoidea virens
Host : Rice
Attack flowers/grains (at the flowering stage produce)
Symptom : yellowish green fungal growths on seeds.
Usually caused minimal damage

False smut of paddy

iii) Citrus scab

Class : Loculoascomycetes

Caused by Elsinoe fawcetti
Host : citrus
Infects leaves, fruits and stem of citrus.
Symptom : Corky lesions and abnormal leaf shape

Citrus scab

iv) Leaf Blight of maize/ corn

Class : Deuteromycetes

Order : Moniliales

Caused by Drechslera maydis (Leaf blight of corn)
Host : corn
Infect at every season,
The worst damage is at seedling stage or young stage.
Drechslera maydis infect and spread vigorously at high humidity.
Spores spread by wind, rain.

Leaf blight of corn

v) Sigatoka disease of banana

Caused by Mycosphaerella musicola (telemorph) / Cercospora musae (anamorph)
It was the first leaf spot disease to have a global impact on bananas but has since been largely displaced by black leaf streak in many banana production areas.

Image result for sigatoka disease of banana

Sigatoka of banana

vi) Moldy rot of rubber

Caused by Ceratocystis fimbriata
Infects tapping panel of rubber

Image result for mouldy rot of rubber tree

vii) South American Leaf Blight (SALB) of rubber

Caused by Microcyclus ulei
This disease occurs only in South America and is unknown in rubber grown in Asia (Malaysia, Indonesia and Thailand)
Quarantine is important

SALB of rubber

vii) Sooty mould disease

Caused by more than one fungi : Tripospermum sp., Capnodium sp., Limacinula sp.)
Infects various crops such as fruit trees (mango, citrus, rambutan etc)
Symptoms mainly of blackish layer of fungal growths on leaves and other plant parts
Sooty mould is a common disease wherever honey dew or sugary subtance secreting insects, such as mango hopper, scales, coccids and mealy bugs are found.
Disease is severe in old and dense orchards where light intensity is low, over the entire surface of twigs and leaves

Sooty mould

ix) Black mildew

Caused by Meliola sp.
Similar with sooty mould disease but fungus forms scattered, blackish growths instead of layers mainly on leaves of mango and other fruit trees.

x) Blast of paddy (Penyakit Karah Padi)

Order : Deuteromycetes

Class : Moniliales

Caused by Pyricularia oryzae (anamorph) / Magnaporthe grisea (teleomorph).
Host : paddy
Infects paddy causing deaths in seedlings
Symptom : diamond shape spots on paddy leaves
This blast disease caused plant become stunted, lessen matured paddy, decrease the weight of grain and its quality.

Blast of paddy

xi) Brown spot of paddy (Bintik Perang)

Class : Deuteromycetes

Order : Moniliales

Caused by Drechslera oryzae
Host : paddy
Symptom : rounded or circle shaped brown spots on paddy leaves (about 1 cm)
Sometimes, too much spot causing the dry leaves.
this disease usually spread on crops on land that has less in nutrients contents,

Brown spot of paddy

xii) Narrow brown leaf spot of paddy (Bintik perang kecil)

Order : Deuteromycetes

Class : Moniliales

Caused by Cercospora oryzae
Host : paddy
Symptom :narrow rounded or circle shaped brown spots on paddy leaves.
Damage is about 2-10mm length, 1mm width.
Infection wide in Asian, North America and Africa.

Narrow brown leaf spot of paddy

xiii) Sheath blight of paddy (Hawar upih)

Class : Deuteromycetes

Order : Agonomycetales

Caused by Rhizoctonia solani
Host : Paddy, grasses (bermudagrass, centipedegrass)
Factors affecting :

high humidity
high temperature
high nitrogen fertilizer

Symptom : cause blackish lesions (about 1 cm length) on leaf sheath and stems. Fungus forms sclerotia and lives under soil for several months untill 1 to 2 years depends on temperature and humidity.

Sheath blight of paddy

xiv) Foot rot

Caused by Sclerotium rofsii
Infects many vegetable crops such as brinjal, chilli, tomato and groundnuts
Causes rots at the base of stems identified by the whitish growths (rhizomorphs) of the fungus
Fungus forms sclerotia

foot rot

xv) Antrachnose

Caused by different species depends on host
Chili : Colletotrichum capsici
French bean : C.dematium, C.truncatum
Mango/Papaya/Rubber/Cocoa : C. gloeosporioides
Banana : C.musae
The fungus generally forms sunken lesions infected fruits or plant parts. Blackish acervulus of fungi are observable on such lesions

Antrachnose of chillies

xvi) Bird eye spot of rubber

Caused by Drechslera hevea
Symptoms on leaves, spot appears as bird eye

xvii) Panama disease or Banana wilt

Caused by Fusarium oxysporum f.sp. cubensis
Major disease of banana world wide causing wilt and death of plants
A cut banana plant stem showing rings of discoloured tissue

Panama disease of banana

C. SLIDES

Sacharomyces cerevesiae
Unicellular, yeast cells in Class Hemiascomycetes

Aspergillus sp.
Conidia produced on sterigmata on conidial heads

Pencillium sp.
Conidia forms are phiallides which are brushlike

Erysiphe cichoracearum

Infects cucurbits
Conidium (oidium) formed in chains on erect conidiophores (asexual stages)
The sexual stage produce cleistothecium (closed ascocarps bearing the ascus and ascospores)