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Department of Botany, DAV College, Jalandhar (PB.)

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BOTANY

Lab Manual

BSc.-II Biotech

Semester IV


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EXPERIMENT NO. 1

AIM : To estimate relative water content in leaves.

THEORY: Relative water content (RWC) is probably the most appropriate measure of plant

water status in terms of the physiological consequence of cellular water deficit. It estimates the

current water content of the sampled leaf tissue relative the maximal water content it can hold at

full turgidity.

REQUIERMENT: Fresh leaves of any plant like mango, peepal or ashoka , oven, physical

balance/electronic weighing balance etc.

PROCEDURE:

1.Take fresh leaves of above mentioned plants i.e. mango, peepal or ashoka.

2 Clean the leaves with water and drie with filter paper/cotton to remove extra water.

3 Take the weight of counted 10 leaves on physical balance. This represents the fresh weight of

leaves(W1).

4.Keep the leaves in oven for approximately 1.5 hours at 1000C temperature.Note theweight of

leaves after 1.5 hours. It is the dry ewight of leaves(W2).

CALCULATIONS:

Weight of water(W3) = Fresh weight (W1). –Dry weight (W2)

Persentage of water content = Weight of water/fresh weight × 100

Persentage of water content = W3/ W1× 100

PRECAUTIONS

1. Leaves should be cleaned and without dust particles.

2 Weighing should be done properly.

3 Leaves should be free from extra water before taking weight.

4. Temperature of oven should be set uniformly at 100°C.


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EXPERIMENT NO. 2

EARLY BLIGHT OF POTATO

Host: Solanum tuberosum

Pathogen: Alternaria solani

Symptoms of diseases

1) Symptoms of early blight occur on fruit, stem and foliage of tomatoes and stem,

foliage and tubers of potatoes.

2) Initial symptoms on leaves appear as small 1-2 mm black or brown lesions and

under conducive environmental conditions the lesions will enlarge and are often

surrounded by a yellow halo Lesions. This so-called “bulls eye” type lesion is

highly characteristic of early blight.

3) Lesions occurring on stems are often sunken and lens-shaped with a light center,

and have the typical concentric rings.

4) The causal pathogen of early blight is the fungus Alternaria solani. There is no

known sexual stage and hence it is classified as a Deuteromycet.

5) The genus Alternaria is a large and important group of pathogenic fungi, which

cause a significant number of important diseases.

6) The asexual conidia are borne singly or in a chain of two on distinct

conidiophores. The beaked conidia normally possess 9–11 transverse septae.

Diseases cycle

1) Alternaria solani overwinters primarily on infected crop debris.

2) Warm, humid (24-29°C/ 75-84°F) environmental conditions are conducive to

infection. In the presence of free moisture and at an optimum of 28-30°C (82-

86°F), conidia will germinate in approximately 40 min.

3) Germ tubes penetrate the leaf epidermis directly or enter through

stomata. Infection of potato tubers usually occurs through wounds in the early

blight is principally a disease of aging plant tissue.

4) Lesions generally appear quickly under warm, moist conditions on older foliage

and are usually visible within 5-7 days after infection.tuber skin inflicted during

harvest.

5) Sporulation occur under conditions of alternating wet and dry period

6) Secondary spread of the disease results from conidia being dispersed mainly be

wind and occasionally by splashing rain or overhead irrigation. Early blight is

considered polycyclic with repeating cycles of new infection. This is the period


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when the disease has the potential to spread rapidly and build up to damaging

levels in the crop.

Infected Leaf

Infected Tuber


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DISEASE CYCLE

Control measures

1) Crop rotation, removal and burning of infected plant debris, and eradication of weed

hosts helps reduce the inoculum level for subsequent plantings.

2) Avoid irrigation in cool cloudy weather and time irrigation to allow plants time to dry

before nightfall.

3) Use certified disease free seed.

4) Use tillage practices such as fall plowing that bury plant refuse.


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EXPERIMENT NO -3

YELLOW VEIN MOSAIC OF BHENDI

Host: Abelmoschus esculentus

Pathogen: Hibiscus Virus

Symptoms

1) Yellow vein mosaic disease is the major limitation in the production of bhendi or okra

(Abelmoschus esculentus), an important vegetable crop of India.

2) The causal agent is the single-stranded DNA Bhendi yellow vein mosaic virus (BYVMV),

which is associated with a beta satellite, both of which are required for infection.

3) BYVMV belongs to the genus Begomovirus, family Geminiviridae..which infect bhendi

and cause mild leaf curling in this host.

4) Symptoms include alternate green and yellow patches, vein clearing, and vein chlorosis

of leaves. The yellow network of veins is very conspicuous, and vein and veinlets are

thickened.

5) In severe cases, the chlorosis may extend to the interveinal area and may result in

complete yellowing of leaves. Fruits are dwarfed, malformed, and yellow green.

Control Measures

1) Uprooting and burning the disease affected plants as soon as they are noticed is the best

method to check the spread of this disease.

2) The disease tolerant variety like pusa Sawani should be cultivated.

3) Control of insect vector by spraying the crop with Dimathoate or Monocrotophos

indirectly helps to check the speed of this disease.


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EXPERIMENT NO 4

BLACK STEM RUST OF WHEAT

Host: Ttriticum vulgare

Pathogen: Puccinia graminis tritici

Symptoms:

The fungus is heteroecious, requiring two hosts to complete its life cycle - the cereal host and the

alternate host.

Symptoms on wheat plant

1) Stem rust on wheat is characterized by the presence of uredinia on the plant, which are

brick-red, elongated, blister-like pustules which are easily shaken off .They most

frequently occur on the leaf sheaths.

2) The characteristic symptoms are brown sporulating pustules occurring in stripes on

leaves and stems.

3) On leaves they develop mostly on the underside but may penetrate to the upperside

4) On leaf sheaths and glumes pustules rupture the epidermis, giving a ragged appearance.

5) Towards the end of the growing season black telia are produced. For this reason stem rust

is also known as 'black rust.The telia are firmly attached to the plant tissue.

Symptoms on Barberry plant

1) Pycnia appear on barberry plants in the spring, usually in the upper leaf surfaces.

2) They are often in small clusters and exude pycniospores in sticky honeydew.

3) Five to ten days later, cup-shaped structures filled with orange-yellow, powdery

aeciospores break through the lower leaf surface.

4) The aecial cups are yellow and sometimes elongate to extend up to 5 mm from the leaf

surface.


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Disease Cycle

Diseases cycle

Puccinia graminis has a complex life cycle featuring alternation of generations. The fungus is

heteroecious, requiring two hosts to complete its life cycle - the cereal host wheat and the

alternate host barberry.

Life cycle on barberry

1. Uredial stage

Urediniospores are formed in structures called uredinia, which are produced by fungal mycelia

on the cereal host 1–2 weeks after infection. The urediniospores are dikaryotic and are formed on

individual stalks within the uredinium. They are spiny and brick-red. Urediniospores are the only

type of spores in the rust fungus life cycle which are capable of infecting the host on which they

are produced, and this is therefore referred to as the 'repeating stage' of the life cycle.


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2. Telial stage

Towards the end of the cereal host's growing season, the mycelia produce structures called telia.

Telia produce a type of spore called teliospores. These black, thick-walled spores are dikaryotic.

Each teliospore undergoes karyogamy (fusion of nuclei) and meiosis to form four haploid spores

called basidiospores. Graminis is able to overwinter independently of a host.

Basidiospores are thin-walled and colourless. They cannot infect the cereal host, but can infect

the alternative host (usually barberry). They are usually carried to the alternative host by wind.

Once basidiospores arrive on a leaf of the alternative host, they germinate to produce a haploid

mycelium which directly penetrates the epidermis and colonises the leaf.

3. Pycnidial stage

Leaf mycelium produces specialised infection structures called pycnia. pycnia produce two

types of haploid gametes, the pycniospores and the receptive hyphae. Splashing raindrops can

also spread pycniospores.A pycniospore can fertilise a receptive hypha of the opposite mating

type, leading to the production of a dikaryotic mycelium.

4. Aecidial stage

This dikaryotic mycelium then forms structures called aecia, which produce a type of dikaryotic

spores called aeciospores. The chains of aeciospores are surrounded by a bell-like enclosure of

fungal cells. The aeciospores are able to germinate on the cereal host but not on the alternative

host). They are carried by wind to the cereal host where they germinate and the germ tubes

penetrate into the plant. The fungus grows inside the plant as a dikaryotic mycelium. Within 1–2

weeks the mycelium produces uredinia and the cycle is complete.

CONTROL MEASURES

1) Cultivation of resistant varieties. Cultivation of early sowing and early maturing varieties.

2) Avoiding thick sowing and heavy irrigation.

3) Destroying the weed plants and diseased tillers.

4) Avoiding heavy doses of nitrogenous fertilizers.

5) Judicious use of potassic fertilizer helps in minimizing the susceptibility of plants.


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Disease Cycle


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EXPERIMENT NO. 5

FALSE SMUT OF RICE

Host: Oryza sativa

Pathogen: Ustilaginoidea virens

Symptoms:

1) Individual rice grain transformed into a mass of yellow fruiting bodies.

2) Growth of velvetty spores that enclose floral parts .Infected grain has greenish smut balls

with a velvetty appearance.

3) The smut ball appears small at first and grows gradually up to the size of 1 cm. It is seen

in between the hulls and encloses the floral parts.

1) Only few grains in a panicle are usually infected and the rest are normal.

2) As the fungi growth intensifies, the smut ball bursts and becomes orange then later

yellowish-green or greenish-black in color.

3) Infection usually occurs during the reproductive and ripening stages, infecting a few

grains in the panicle and leaving the rest healthy.

Prevention and control

1) Use of diseased-free seeds that are selected from healthy mother plants.

2) Control insect pests.

3) Split nitrogen application.

4) Removal and proper disposal of infected plant debris.

5) Avoid field activities when the plants are wet.

6) Spraying of copper oxychloride at 2.5 g/litre or Propiconazole at 1.0 ml/litre at boot leaf

and milky stages will be more useful to prevent the fungal infection.

7) Seed treatment with carbendazim 2.0g/kg of seeds.

Grains Transformed into a Mass of Yellow Fruiting Bodies


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EXPERIMENT NO. 6

DOWNY MILDEW OF BAJARA

Host: Pennisetum typhoides

Pathogen: Sclerospora graminicola

Symptoms

1) Leaf symptoms begin as chlorosis (yellowing) at the base of the leaf lamina, and

successively top leaves show greater leaf coverage by symptoms.

2) Infected plants are generally stunted and do not produce earheads.

3) The floral parts are transformed into leaf like structures, which can be total or partial,

hence the name 'green ear’.

Control Measures

1) All cultural methods are aimed at manipulating the environment to the advantage of the

host and disadvantage of the disease causing fungus.

2) Use disease-free seed and effective removal of disease infested plant material in the field

after harvest of the crop are essential to reduce the primary inoculum in the soil.Downy

mildew-infected plant material should be burnt, or if feasible the field should be plowed

deeply to bury infected the plant material.

3) Roguing

4) The systemic fungicide Metalaxyl was used successfully to control downy mildew in

pearl millet.

5) Use of resistant cultivars is the most cost-effective method for the control of downy

mildew. Four open pollinated varieties, WC-C75, ICMS 7703, ICTP 8203, and ICMV

155 released in India are resistant to downy mildew.


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EXPERIMENT NO. 7

BUNCHY TOP OF BANANA

Host: Musa paradisiaca

Pathogen: Banana Bunchy Top Virus

Symptoms

1) Plant has been infected with BBTV are usually severely stunted, with leaves that do not

expand normally and remain bunched at the top of the pseudostem.

2) These leaves are stiff and erect, are shorter and narrower than normal leaves, and have

chlorotic (yellow) and wavy edges and bunched.

3) Bunchy symptoms commonly seen on the young or small plants in advanced stages of the

disease.

4) Plant with severe BBTV infections will not flower or bear fruit.

5) Decaying of root system of infected plants.

6) Disorganisation of phloem to some extent.

Control Measures

1) Quarantine measure should be followed in diseases free area.

2) Eradication and roguing of diseased suckers and plant.

3) Use of certified virus free suckers.

4) Killing of plant by the use of some hormones weed killer MCPA (2-methyl, 4-

chlorophenoxy acetic acid)


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EXPERIMENT NO. 8

LATE BLIGHT OF POTATO

Host: Solanum tuberosum

Pathogen: Phytophthora infestans

Symptoms of Diseases

1) Phytophthora infestans is a specialized pathogen of potato and can cause infections in

Potato foliage and tubers.

2) Young lesions are small and appear as dark, water-soaked spots. These leaf spots will

quickly enlarge under cool, wet conditions and a white mold will appear at the margins

3) Stems are similarly affected and complete defoliation (browning and shrivelling of leaves

and stems) can occur within 14 days from the first symptoms.

4) Infected potato tubers have a dry, corky rot that may be brown or reddish. Tubers are

symptomless at the initial stages of infection but often develop symptoms in storage.

5) The fungus produces a foul odour where infection is severe.

6) At first, the infected tubers have a brown to purple sunken discoloration of the skin.

Disease cycle

1) The organism causing potato late blight typically infected tubers, infected plants, or seed.

Infected tubers sprout, the organism develops, and under moist conditions, spore

production is initiated

2) Infected tubers sprout, the organism develops, and under moist conditions, spore

production is initiated. These spores are carried primarily by wind to nearby fields. With

the presence of free moisture, these spores germinate; infect the potato plant, and the

cycle repeats.

3) Infection of potato foliage begins when plants emerg from diseased seed potatoes. Spores

on infected potato leaves are washed down into the soil where they may infect tubers.

4) Development of the lesions is favored by cool, moist weather.

5) Lesions appear on leaves in about 7 days after infection.

6) Leaf lesions may become visible as small, lighter green areas as soon as four days after

infection.

7) About 7 days after infection, the lesion will sporulate. White, fluffy reproductive

zoospores are abundant on the edge of the lesion on the underside of the leaf.

8) Older lesions will sporulate only when temperatures are between 60°F and 70°F with

more than 10 hours of high relative humidity.


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PotatoLeaf Potato Stem

Potato Tuber

Control Measures:

1) The addition of a seed treatment effective in reducing late blight should be considered.

2) Growers should plant certified “disease-free”seed.

3) Do not plant store potatoes or tubers harvested from blighted plants during the previous

season.

4) Keep developing tubers covered with soil to protect them from late blight.

5) If late blight is evident, harvest and eat tubers right away. Don’t store them.

6) Fungicides should be applied based on a forecasting scheme.


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7) Vine killing is an important step for late blight control. Fields with late blight should be

thoroughly dead before harvest.

Disease Cycle


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EXPERIMENT NO. 9

BACTERIAL BLIGHT OF RICE

Host: Oryza sativa

Pathogen: Xanthomonas oryzae

Symptoms:

1) Bacterial blight is found worldwide and particularly destructive in Asia during the heavy

rains of the monsoon season..

2) Bacterial blight is a vascular disease resulting in tarnish grey to white lesions along the

veins.

3) Lesion on the tip of the leaves, increases in length downwards and turns into yellow to

straw-coloured stripes with wavy margins.

4) In the seedling stage leaf tips are affected.

5) Bacterial exudate oozes out of the lesions in the form of small droplet.

6) Hardening of these droplets results in to formation of hard yellow coloured resinous

granules.

7) Finally leaves dry up and plant die.

8) Pathogen remains in the vascular bundle, glumes and even in the endosperm of the grains

in case of severe infection. Excess application of nitrogen and late top dressing increases

the disease inside.

Disease cycle

The causal bacterium Xanthomonas oryzae is a gram negative non-spore forming rod shaped

bacterium which is motile by single polar flagellum. Colonies on culture media are round and

yellow in colour. Self sown plants in low lands, infected straw and stubble, Wild rice and weeds

during the off season serve as a source of primary inoculum. Infected straw, when used to

produce a pigment called ‘xanthomonadin’, Irrigation canal, serves as the primary source of

inoculums. High humidity, moderate temperature, prolonged rainfall or drizzling condition,

cyclone, flood and windy or stormy condition favours the development and spread of the disease.

Control measure:

1) Grow resistant variety like Improved Samba Mahsuri, Improved Pusa Basmati 1, or

moderately resistant varieties like IR 20, IR 64, Swarna, PR 113.

2) Spraying of Agrimycin- can significantly reduce the disease in field.

3) Application of stable bleaching powder @ 12.5 kg/ha can

4) Reduce the intensity of the disease.


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5) Application of nitrogen fertilizer at the time of transplanting or at the time of flowering

initiation results in lowering the intensity of diseases development.

6) Adoption of cultural practices like clean fields and bunds, avoidance of field to field

irrigation and use of healthy seeds will reduce the intensity of the disease.


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EXPERIMENT NO. 10

RED ROT OF SUGARCANE

Host: Saccharum officinarum

Pathogen: Colletrotrichum falcatum

Symptoms

1) Red rot occurs in various parts of the cane plant but it is usually considered a stalk and a

seed-piece disease.

2) Its symptoms are highly variable depending upon the susceptibility of the sugarcane

variety and the environment.

3) Symptoms may not be readily apparent in the field, especially in the early stages of the

disease. In the later stages of the disease, red rot may cause standing cane to “break

down”

4) Diagnostic symptoms can best be observed by splitting the stalk lengthwise. The infected

tissues have a dull red color interrupted by occasional whitish patches across the stalk.

These white patches are specific to the disease and are of significance in distinguishing

red rot from other stalk rots.

5) Reddened vascular bundles may also pass through to the healthy tissues.

6) In susceptible varieties the red color, sometimes along with some gray color, may be seen

throughout the length of the stalk.

Disease Cycle

1) Midrib lesions are probably the major source of inoculum during the growing season.

Diseased stalks generate a great deal of inoculum.

2) Dissemination of the inoculum takes place by wind, rain, heavy dews and irrigation

water. Infected plant material can readily spread or cause secondary infections.

3) Crop debris or stubble may also provide inoculum to infect a new crop. Although the

fungus is not a true soil-borne organism, spores washed into the soil may produce

infection in planted seed pieces.

4) Hosts other than sugarcane are not considered important inoculum sources.

5) Climatic factors affect both the spread and severity of red rot. In newly-planted cane, the

disease is favored by excessive soil moisture, drought conditions, and low temperatures.

Control Measures

1) The use of resistant varieties is the most effective method of prevention and control.

Department of Botany, DAV College, Jalandhar (

2) The incidence of red rot can be reduced through good cultural practices, such as clearing

fields of excessive trash and efficient drainage. Agronomic practices that hasten

germination are important in reducing seed rotting and obtaining good stands.

3) The avoidance of planting susceptible cultivars during excessively cool and wet weather

has been effective in several countries.

4) Regular roguing of diseased plants, burning of trash, plou

maintenance of proper soil moisture, and prompt harvesting of infected or susceptible

crops are other management practices recommended for red rot control.

5) Heat treating of seed cane has also been effective in controllin

red rot.


The incidence of red rot can be reduced through good cultural practices, such as clearing


mportant in reducing seed rotting and obtaining good stands.

The avoidance of planting susceptible cultivars during excessively cool and wet weather

has been effective in several countries.

Regular roguing of diseased plants, burning of trash, ploughing out badly affected fields,


crops are other management practices recommended for red rot control.

Heat treating of seed cane has also been effective in controlling seed piece infection of

Disease Cycle

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The incidence of red rot can be reduced through good cultural practices, such as clearing


mportant in reducing seed rotting and obtaining good stands.

The avoidance of planting susceptible cultivars during excessively cool and wet weather

ghing out badly affected fields,


seed piece infection of


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EXPREIMENT No. 11

TOBACCO MOSAIC VIRUS (TMV) OF POTATO

Host: Solanum nigrum

Pathogen: Virus

Symptoms

1) Viruses are intracellular (inside cells) pathogenic particles that infect other living

organisms.

2) Tobacco mosaic virus or TMV the causal agent of TMV—viruses are either rod-shaped.

3) TMV, potato virus Y (PVY), is examples of a short rigid rod-shaped, a long flexuous

rod-shaped, and an isometric virus, respectively.

4) Viruses consist of an inner core of nucleic acid (either ribonucleic acid [RNA] or de-

oxyribonucleic acid [DNA]) surrounded by an outer sheath or coat of protein (referred to

as the capsid.

5) Wounds in plants can occur naturally, such as in the branching of lateral roots.

6) The organism creating the wound can also be carrying and can pass or transmit the virus.

Organisms that transmit pathogens are called vectors.

7) The seedling offspring of a virus-infected plant is usually, but not always, free of the

virus, depending on the plant species and the kind of virus.

8) Insect transmission is perhaps the most important means of virus transmission in the

field. Some plant viruses can also be transmitted in pollen grains or by seed.

Control Measure

1) Once plants are infected, little can be done to free them from the virus.

Genetic Host Resistance

i. Since different cultivars and species show different degrees of resistance

to some viruses, resistant types should be planted whenever they are

available. Recent advances in plant cell molecular biology and virology

have lead to the development of genetically modified plants with superior

resistance to some viruses.

Cultural Practices

There are numerous cultural practices that can be used to reduce plant losses due to virus

infection.


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a. Scouting and removal of symptomatic plants or known alternative weed or volunteer

plants that may serve as a reservoir for a given virus.

b. The use of clean or sanitized tools and equipment.

c. Hand washing

d. The use of disposable overgarments

e. Rotations to non-host crops

f. Geographic isolation of production facilities may also help avoid losses caused by plant

viruses

g. The isolation of newly received plant material prior to its introduction into the rest of a

production system can also minimize the unintentional introduction of pathogens. This

procedure, called heat therapy, frees individual plants or cuttings of the virus. The clean

tissue is then used as a propagative source, allowing large-scale production of virus-free

plants

h. Some viruses are permanently inactivated by prolonged exposure of infected tissue to

relatively high temperatures—for example, 20 to 30 days at 38 degrees C (100 degrees

F). This procedure, called heat therapy, frees individual plants or cuttings of the virus.

The clean tissue is then used as a propagative source, allowing large-scale production of

virus-free plants


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EXPERIMENT NO. 12

Aim: To measure osmotic potential of a tissue by chardokov’s method.

Theory: Osmotic potential or water potential is the difference in the chemical potential or free

energy per unit molal volume in a system then that of pure water at the same temperature.

Requirements: Peeled potato, sugar solution of different molar concentration, methylene blue,

test tube stand, test tube, pipettes (10 ml, 1ml) dropper, corkborer, forceps, aluminium foil,

beakers, distilled water etc.

Procedure:

1) Weight 3.42 g of sugar and dissolve in 100 ml of distilled water.

2) Take 5 test tube and different molar concentration of sugar solution in them and marked

them as 0.10, 0.20, 0.30, 0.40 and 0.50.

3) Then cut small cylindrical pieces of potato tuber 2 cm in size and dried in the folds of filter

paper.

4) Out of two sets of test tubes, put small pieces of potato tubers in the first set in the equal

number.

5) Add drop of methylene blue in each test tube of set one.

6) Leave the set one, undisturbed for 20 minutes.

7) Put a drop of coloured solution from each test tube to its corresponding test tube in set 2.

Observe the movement of drop in sugar solution weather it moves upward, downwards or

simply diffuse.

Precautions:

1) Weighing should be proper

2) Test tubes should be neat and clean.

3) Concentration of sugar solution made very carefully.

4) Sugar concentration should drop in the middle of test tube of set 2.


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EXPERIMENT NO. 13

LOOSE SMUT OF WHEAT

Host: Triticum aestivum

Pathogen: Ustilago tritici

Symptoms

1) At early maturity stage, signs of the pathogen start to appear in wheat fields on a few

number of wheat heads (smutted heads) that carry millions of teliospores.

2) This late symptom can be seen clearly at the field inspection on a higher level than the

healthy un-matured heads.

3) The smutted heads consist of a powdery mass of the fungus teliospores covered by a

delicate grayish membrane that will burst releasing the spores to be blown by wind and

fall on the inflorescences of healthy plants and germinate to invade the ovary of the

flower.

Diseases Cycle:

1) Germination of teliospores on the flowers of wheat heads produces dikaryotic mycelium

that penetrates the ovary invading all parts of the seed.

2) The mycelium overwinters until seed germination, then it regains its activity growing

intercellularly in the tissues of embryo then the seedling till it invades the whole plant

with no visible sign of its growth.

3) When plants reaches the head emergence stage, the mycelium starts to invade the

spikelets and young kernels, then the mycelium thickens and fragment forming millions


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of teliospores turning the kernels into powdery black masses covered by grayish delicate

membranes.

4) The smutted heads will develop sooner than healthy ones allowing spores to be blown by

the wind to fall on healthy flowers and germinate forming promycelia.

5) The promycelia infect ovaries of newly emerging heads of healthy plants and establish in

the seeds' tissues as dormant mycelium till the new growing season and seeds

germination.

Disease Cycle

Management of Loose Smut:

1) Growing resistant varieties.

2) Using certified seeds.

3) Seed production fields should be isolated from commercial fields.

4) Seed treatment with hot water or solar heat (not useful for commercial use).


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4) Field inspection and roguing smutted heads in the field at the early heading stage.

5) Clearing the field after harvesting from plant remains that may help spread the disease.

6) Seed certification schemes can help reduce the disease spread significantly. Tolerance

levels of infested seeds ranges between 0.1-0.5% depending on the different classes of

seeds.

7) Seed health testing through embryo count method (Mathur 1993) or crown test to avoid

infested seed lots.

8) Seed treatment with systemic fungicides as carboxin, carbathiin, benomyl, triadimenol,

triadimefon, pyracarbolid, terbutrazole, carbendazim, difenoconazole, etaconazole,

ethyltrianol, flutriafol, furmecyclox, myclobutanil, or nuarimol.

9) Foliar application of broad spectrum systematic fungicides including conazole fungicides

in a 3 time spray program has markedly reduced the disease incidence (Jones 1999).

10) Recent researches have been conducted to use PCR and ELISA techniques in the

assessment of loose smut incidence in seed lots

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