Strategies for Enhancement in Food Production {Class 12th Biology}

Unit: Microbes in Human Welfare

Chapter: Strategies for Enhancement in Food Production

Class: 12th Biology

Presented By: Dr. Priyanka Patade

Animal Husbandry

✤ The agricultural practice of breeding and raising livestock.

✤ Deals with care and breeding of livestock like buffaloes, cows, pigs, horses, cattle, sheep, camels, goats etc.

✤ Extended form includes poultry farming and fisheries.

✤ Fisheries include rearing, catching selling etc. of fish, molluscs (shell fish) and crustaceans (prawns, crabs etc.)

Objectives of Animal Breeding

⏩ Improved growth rate ⏪

⏩ Increased production ⏪

⏩ Improve Desirable Qualities ⏪

⏩ Improved resistance to diseases ⏪

⏩ Improved resistance to adverse environmental conditions ⏪

1. Dairy Farm Management

Dairying is the management of animals for milk and its products for human consumption. In dairy farm management, we deal with processes and systems that increase yield and improve quality of milk.

Selection of good breeds having high yielding potential, combined with resistance to diseases is very important, such as Cattle have to be housed well, should have adequate water and be maintained disease free.

The feeding of cattle should be carried out in a scientific manner (quality and quantity of fodder).

Stringent cleanliness and hygiene are importance while milking, storage and transport of the milk and its products.

Regular visit by a veterinary doctor would be mandatory.

2. Poultry Farm Management

Poultry is the class of domesticated fowl used for food or for their eggs.

Important components of poultry farm management:

⤷ Selection of disease free and suitable breeds

⤷ Proper and safe farm conditions

⤷ Proper feed and water

⤷ Hygiene and health care

3. Bee-keeping / Apiculture

Bee-keeping or Apiculture is the maintenance of hives of honeybees for the production of honey.

There are several species of honeybees which can be reared.

Of these, the most common species is Apis indica.

Honey is a food of high nutritive value and also finds use in the indigenous systems of medicine.

Honeybee also produces beeswax, which finds many uses in industry, such as in the preparation of cosmetics and polishes of various kinds.

The following points are important for successful bee-keeping

⤷ Knowledge of the nature and habits of bees,

⤷ Selection of suitable location for keeping the beehives,

⤷ Catching and hiving of swarms (group of bees),

⤷ Management of beehives during different seasons,

⤷ Handling and collection of honey and of beeswax.

⤷ Keeping beehives in crop fields during flowering period increases pollination efficiency and improves the yield.

4. Fisheries

Fishery is an industry devoted to the catching, processing or selling of fish, shellfish or other aquatic animals. It is also known as Pisciculture.

Freshwater fishes – Catla, Rohu and common crab; Marine fishes – Sardines, Mackerel and Pomfretes.

In order to meet the increasing demands on fisheries, different techniques have been employed to increase production.

Aquaculture is the rearing, breeding of aquatic animals and aquatic plants.

Animal Breeding

A group of animals related by descent and similar in most characters like general appearance, features size, configuration, etc. are said to be a breed.

Animal breeding aims at increasing the yield of animals and improving the desirable qualities of the produce.

When breeding is between animals of the same breed it is called Inbreeding, while crosses between different breeds are called Out-breeding.

Inbreeding

It refers to the mating of more closely related individuals within the same breed for 4-6 generations. The breeding strategy is, superior males and superior females of the same breed are identified and mated in pairs.

Inbreeding increases Homozygosity. However, continued inbreeding, especially close inbreeding, usually reduces fertility and even productivity. This is called Inbreeding Depression.

Whenever this becomes a problem, selected animals of the breeding population should be mated with unrelated superior animals of the same breed. This usually helps restore fertility and yield.

Out-breeding

It is the breeding of the unrelated animals, which may be between individuals of the same breed or between different breeds or different species.

Out-crossing

This is the practice of mating of animals within the same breed, but having no common ancestors on either side of their pedigree up to 4-6 generations.

The offspring of such a mating is known as an out-cross.

A single outcross often helps to overcome inbreeding depression.

Cross-breeding

In this method, superior males of one breed are mated with superior females of another breed.

Cross-breeding allows the desirable qualities of two different breeds to be combined.

The progeny hybrid animals may themselves be used for commercial production.

For example, Hisardale is a new breed of sheep developed in Punjab by crossing Bikaneri ewes and Marino rams.

Interspecific Hybridisation

In this method, male and female animals of two different species are mated.

In some cases, the progeny may combine desirable features of both the parents, and may be of considerable economic value. Eg. Mule.

Artificial Insemination

Controlled breeding experiments are carried out using artificial insemination.

The semen is collected from the male that is chosen as a parent and injected into the reproductive tract of the selected female by the breeder.

The success rate of crossing mature male and female animals is fairly low even though artificial insemination is carried out.

To improve chances of successful production of hybrids, other means are also used (MOET).

Multiple Ovulation Embryo Transfer Technology (MOET)

MOET

It is used to improve chances of successful production of hybrids.

⤷ Cow is administered hormones with FSH-like activity.

⤷ Induce follicular maturation and super ovulation.

⤷ Production of 6-8 eggs instead of one egg per cycle.

⤷ The female is either mated with an elite bull or artificially inseminated

⤷ Non-surgical recovery of fertilized eggs at 8-32 cells stages.

⤷ Each one transferred to surrogate mother.

⤷ The genetic mother is available for another round of super ovulation.

⤷ This technology is used to increase herd size in a short time.

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Plant Breeding

What is Plant Breeding?

Plant breeding is the purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, giver better yields and are disease resistant.

Green revolution was dependent to a large extent on plant breeding techniques for development of high – yielding and disease resistant varieties in wheat, rice, maize, etc.

Steps of plant breeding

The main steps in breeding a new genetic variety of a crop are:

a) Collection of variability – Collection and preservation of all the different wild varieties, species and relatives of the cultivated species.

b) Evaluation and selection of parents – Evaluation is done to identify plants with desirable characters. The selected plants are multiplied and used in the process of hybridization.

c) Cross hybridization among the selected parents – By cross hybridizing the two parents to produce hybrids that genetically combine the desired characters in one plant.

d) Selection and testing of superior recombinants – The selection process is crucial to the success of the breeding objective and requires careful scientific evaluation of the progeny. These are self pollinated for several generations till they reach a state of uniformity, so that the characters will not segregate in the progeny.

e) Testing, release and commercialization of new cultivars – This evaluation is done by growing these plants in the research fields and recording their performance under ideal fertilizer application irrigation, and other crop management practices. It will be followed by testing the materials in farmers’ fields, for at least three growing at several locations in the country.

Examples

✤ In 1963, several varieties such as Sonalika and Kalyan Sona, which were high yielding and disease resistant, were introduced all over the wheat-growing belt of India.

✤ Semi-dwarf rice varieties were derived from IR-8, and Taichung Native-1 were introduced in 1966. Later better-yielding semi-dwarf varieties Jaya and Ratna were developed in India.

✤ Saccharum barberi and Saccharum officinarum were crossed to get the desirable qualities of high yield, thick stems, high sugar and ability to grow in the sugar cane areas of north India. Sugar cane

✤ Millets Hyrbid maize, jowar and bajra have been developed in India, which are high yielding and resistant to water stress.

Plant Breeding for Disease Resistance

Methods of Breeding for disease resistance

The various sequential steps are;

 1. Screening germplasm for resistance: Germplasm is the sum total of all the alleles of the genes present in a crop and its related species

2. Hybridization of selected parents: Hybridisation is the most common method of creating genetic variation. Hybridisation is crossing of two or more types of plants for bringing their traits together in the progeny.

3. Selection and evaluation of the hybrids: Selection of parents is picking up seeds of only those plants for multiplication which have the desired traits. For example, grain length in rice is variable— longer grains, intermediate grains and shorter grains.

4. Testing and release of new varieties: The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance, etc. This evaluation is done by growing these in the research field and recording their performance under ideal fertiliser (application), irrigation, etc.

Mutation Breeding

It is the process by which genetic variations are created through changes in the base sequence within genes resulting in the creation of a new character or trait not found in the parental type.

It is possible to induce mutations artificially through use of chemicals or radiations, and selecting and using the plants that have the desirable character as a source in breeding.

For example, in mung bean, resistance to yellow mosaic virus and powdery mildew were induced by mutations.

Resistance to yellow mosaic virus in bhindi (Abelmoschus esculentus) was transferred from a wild species and resulted in a new variety of A. esculentus called Parbhani kranti.

 Plant Breeding for Developing Resistance to Insect Pests

Insect resistance in host crop plants may be due to morphological, biochemical or physiological characteristics.

Hairy leaves in several plants are associated with resistance to insect pests, e.g., resistance to jassids in cotton and cereal leaf beetle in wheat.

High aspartic acid, low nitrogen and sugar content in maize leads to resistance to maize stem borers.

Smooth leaved and nectar-less cotton varieties do not attract bollworms.

Plant Breeding for Improved Food Quality

Diets lacking essential micronutrients – particularly iron, vitamin A, iodine and zinc – increase the risk for disease, reduce lifespan and reduce mental abilities.

A far greater number–three billion people – suffer from micronutrient, protein and vitamin deficiencies or ‘hidden hunger’ because they cannot afford to buy enough fruits, vegetables, legumes, fish and meat.

More than 840 million people in the world do not have adequate food to meet their daily food and nutritional requirements.

Biofortification

It is the process of breeding crops with higher levels of vitamins and minerals, or higher protein and healthier fats. Breeding for improved nutritional quality is undertaken with the objectives of improving;

⤷ Protein content and quality

⤷ Oil content and quality

⤷ Vitamin content

⤷ Micronutrient and mineral content

For example, Vitamin A enriched carrots, spinach, pumpkin; Vitamin C enriched bitter gourd, mustard, tomato; Iron and Calcium enriched spinach and Protein enriched Beans.

Single Cell Protein (SCP)

Single cell proteins can be produced from algae, fungi, yeasts and bacteria.

Some low-cost substrates are used to produce microbial biomass to produce single cell proteins.

SCP is rich in high quality protein and is low in fat content, hence it is a desirable human food.

SCP should also reduce the pressure on agricultural production systems for the supply of proteins and it can reduce environmental pollution.

For example, microbes like Spirulina can be grown easily on materials like:

⤷ Waste water from potato processing plants, straw,

⤷ Molasses,

⤷ Animal manure and

⤷ Even sewage,

⤷ To produce large quantities and can serve as food rich in protein, minerals, fats, carbohydrate and vitamins.

Some Common Microbes as SCP producers:

(i) Cyanobacteria – Spirulina

(ii) Bacteria – Methylophilus methylotrophus

(iii) Yeasts – Candida utilis

(iv) Filamentous fungi – Fusarium gramiearum

Advantages of SCP

(i) It is rich in high quality protein and poor in fat content,

(ii) It reduces the pressure on agricultural production systems for the supply of the required proteins,

(iii) SCP production is based on industrial effluents so it helps to minimise environ- mental pollution,

(iv) SCP can be produced in laboratories throughout the year.

Plant Tissue Culture

Plant tissue culture refers to the maintenance and growth of plant cells, tissues and organs on a suitable synthetic medium in vitro and the whole plants could be regenerated from explants.

Explant: An explant is the plant part excised from a specific location in a plant, to be used for initiating a culture.

In this tissue culture process, explant, i.e., any part of a plant is taken out and grown in a test tube, under sterile conditions in special nutrient media.

This capacity to generate a whole plant from any cell / explant is called Totipotency.

This method of producing thousands of plants through tissue culture is called Micropropagation.

Each of these plants will be genetically identical to the original plant from which they were grown i.e., they are somaclones.

Explant and Callus

Meristem Culture

The recovery of healthy plants from diseased plants can be done by meristem culture.

Although the plant is infected with a virus, the meristem (apical and axillary) is free of virus. Hence, one can remove the meristem and grow it in -vitro to obtain virus-free plants.

Somatic Hybridisation / Somatic Hybrids/ Protoplast Fusion

The first step in somatic hybridization is to remove the cell wall by digesting it with enzymes like pectinase and cellulase.

Isolated protoplasts from two different varieties of plants – each having a desirable character – can be fused to get hybrid protoplasts, which can be further grown to form a new plant.

These hybrids are called somatic hybrids while the process is called somatic hybridization.

For example, a protoplast of tomato is fused with that of potato to form new hybrid plants combining tomato and potato characteristics.

Pomato Plant

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Other Topics

Human Health and Diseases {Class 12th Biology}

Reproductive Health {Class 12th Biology}