ASSIGNMENT ON PBG- 513

TOPIC – Plant Breeding , Its Objectives And Historical Development- Pre And Post Mendelian Era

Presented by:-Avinash Gupta

M.Sc. (pre.)Plant breeding & geneticsRCA , MPUAT, Udaipur

CONTENTS

1. Definition and Nature

2. Role of Plant Breeding

3. Challenges before plant breeder

4. Objectives of plant breeding

5. Activities in Plant Breeding

6. History of Plant Breeding

Plant Breeding:-Plant breeding is the art, science and technology of changing the heredity of

plants for human welfare.

Nature of Plant Breeding:-

1. Art

•In earlier days man depends on his skills and judgement in

selecting better plants. He knew nothing about the inheritance of

characters, role of environment in producing them and the basis of

variation in various plant characters. His method of selection was

designed without the understanding of principles of inheritance.

•Therefore during primitive time plant breeding was largely an art

and very less science was involved in that. Even today success of

selection depends upon ability of the person involved in the

selection.

2. Science•Plant breeding is considered as the current phase of crop evolution. As the

knowledge of genetics and other related science progresses plant breeding become

less art and more science.

•Especially, discovery of Mendels̕ work in 1900 added a lot to the knowledge of

science.

•Selection of desirable plant even today is an art it depends on the skill of a

person. But alone skill is not enough, modern plant breeding is a combined effort

of art and understanding and use of genetic principles.

3. TechnologyProduct of all plant breeding activities, whether dependent on the art or science, is

improved variety, hybrids, synthetics and composites. This product is utilized by

farmers for commercial cultivation.

Therefore, plant breeding can be rightly viewed as a technology since it

generates a useful product.

Role of Plant Breeding:-

Human beings are dependent on the plants for:

1. Food :- Breeding of field crops provides us food either directly (food

grains) or indirectly (meat and milk).

2. Shelter :- In addition to food by produce of agriculture farms are used in

making shelter by farmers of rural areas.

3. Clothing :- Breeding for fibre crops like cotton provides clothes for the

human population.

4. Fuels :- Crops like Euphorbia and Jatropha are used for Biofuel

production. Breeding of such crops tackles the problems of energy

production for rapidly increasing human population. Now a days , Maize is

also used as an important source of Ethanol production.

5. Drugs :- Breeding of medicinal plants plays an important role in

production of many important drugs. These drugs are used for treatment

of various human and animal diseases.

6. Entertainment:- Flowers play an essential role in peoples celebrations

and everyday lives like weddings, Christmas etc. most of the medicinal

plants are seasonal in nature. Shifting the seasonal timing of reproduction

is a major goal of plant breeding efforts to produce novel varieties that

are better adapted to local environments and changing climatic conditions.

Challenges before Plant Breeder :-

1. Increasing population:- At present, the world population stand at 6.3

billion and will reach at 10-12 billion during the next 50-70 years. The main

problem from breeding respect is that the population is growing faster than

increases in food productivity, to reduce the use of harmful agrochemicals

and to produce nutritious and healthful food is greater today.

2. Squeezing arable land :- Day-by-day the total arable land for

agriculture is decreasing due to urbanization and industrial development.

Breeders have to tackle this problem by releasing improved varieties of

major crops which gives better production per unit area.

3. Erratic rainfall :- In India, rainfall is erratic, unpredictable and unevenly

distributed. Over 80% of the annual rainfall is received in the four rainy

months of June to September. Therefore, varieties which can tolerate dry

spells and perform better at low water availability are needed to be develop

by Indian Breeders.

4. Mechanization:- The variety developed by plant breeders should give

response to application of fertilizers, manures, irrigation and should be

suitable for mechanical cultivation .

Objectives of Plant Breeding:-The prime objective of plant breeding is to develop superior plants over the

existing ones in relation to their economic use. The objectives of plant breeding

differ from crop to crop. A brief account of some important objectives are-

1. Higher productivity- Increased yield has been the ultimate aim of most

plant breeders. This can be achieved by developing more efficient genotypes

having greater physiological efficiency.

2. Improved quality- Improved quality of agricultural products has

contributed a lot to the human well-being. Quality characters vary from one

crop to another crop. For example, Grain size, colour , milling, and baking

qualities in wheat (Triticum aestivum).

3. Disease and Insect Resistance- Resistance varieties offer the

cheapest and most convenient method of disease and insect management. In

some cases, they offer only feasible means of control. eg. Rust in Wheat.

4. Varieties for new seasons- The varieties for new seasons have been

developed by adjusting the growth cycle of the variety to suit better to the

available growing season. Traditionally maize is a kharif crop but, scientists

are now able to grow maize throughout the year. Similarly, Mung is now

grown as a summer crop in addition to the main kharif crop.

5. Modification of agronomic characteristics- modification of

agronomic characteristics such as plant height, tillering, branching, erect or

trailing habit etc. is often desirable. For example, dwarfness in cereals is

generally associated with lodging resistance and fertilizer responsiveness.

6. Change in maturity duration- It permits new crop rotations and

often extends the crop area. Development of wheat varieties suitable for late

planting has permitted rice-wheat rotation. This objective is more desirable

especially in those areas where multiple cropping system has been followed.

7. Photo and thermo insensitivity- Development of photo and

thermo insensitive wheat and photo insensitive rice varieties has permitted

their cultivation in new areas. eg. Cultivation of wheat in Kerala and W.B.,

cultivation of rice in Punjab and Himachal Pradesh..

8. Synchronous maturity- Synchronous maturity is highly desirable

in crops where several pickings are necessary. Eg. Mungbean, pigeon pea,

cotton etc.

9. Non-shattering characteristics- It would be of great value in

crops like mung, castor, soybean etc. where shattering is a major problem

in case of many commercial varieties.

10. Determinate growth- Development of varieties with determinate

growth is desirable in crops like mung, pigeon pea, cotton, etc.

11. Dormancy- Dormancy plays both beneficial and harmful role according

to the need of grower. For example, if we want next crop immediate after

harvesting of previous crop, in such case dormancy is not required. But if we

want to store the seed for its future purpose, a period of dormancy is essential.

12. Elimination of toxic substances:- some crops have toxic substances

which must be eliminated to make them safe for consumption. For example,

• Khesari (Lathyrus odoratus) seeds have a neurotoxin, β- N- oxalyl - α-β-

diaminopropionic acid (BOAA) that causes paralysis in humans.

•Similarly, elimination of Erusic acid from Brassica oil and Gossypol from seed

cotton is necessary to make them fit for consumption.

Activities in plant breeding:

1.Creation of variation :-Variation means differences among

individuals of a population or species for a specific character. Genetic

variation is the source of raw material for selection. These are heritable

and are transmitted from one generation to other. Such variation is useful

in selection. Success of a breeding programme usually depends on the

desired genetic variation. It can be done in following ways i.e.

domestication, germplasm collection, plant introduction, hybridization,

polyploidy, mutation, somaclonal variation and genetic engineering.

2. Selection:-

During selection, the individual plant or group of plants having the

desired characters are picked up from a population eliminating the undesirable

ones. Those plants are selected which are looking promising for the character

on thee basis of phenotype. The selected plants are then allowed to grow for

setting their seeds. Seeds are selected and again a new crop is developed. This

process is repeated again and again till the desired result is achieved. Selection

acts on the genetic variation present in a population and produces a new

population with improved characters.

3. Evaluation

The newly selected lines/strains/populations are tested for yield and other traits

and their performance is compared with existing best varieties called Checks. If

the new lines/strain/population shows superior performance to the checks, it is

released and notified as a new variety.

4. Multiplication

This step concerns with large scale certified seed production of the released and

notified variety.

5. Distribution

Certified seed is ultimately sold to the farmers who use it for commercial crop

cultivation.

CreationOf

variation

selection

Evaluation

multiplication

distribution

Naturally existing variability

Creation of new

variability

Activities in plant breeding

Germplasm collection

Plant Introduction

Domestication

Hybridization

Mutation

Polyploidy

Genetic engineering

Somaclonal variation

History of Plant Breeding:-

In broad sense history of plant breeding can be divided into 4 parts

1. Pre Mendelian era:- before 1900

2. Mendelian era:- 1900 to 1920.

3. Post Mendelian era:- 1921 to 1950

4. Modern era:- after 1950

1. Pre Mendelian era:-

•9000 BC First evidence of plant domestication in hills above Tigris River

•5000 BC Agricultural communities exist in Mesopotamia

•4000 BC Egyptians used yeast in wine and bread making

•3000 BC Domestication complete for all important food crops in the old world

•1000 BC Domestication complete for all important food crops in the new

world.

•700 BC Assyrians and Babylonians - Hand pollination of date palm

•1665 Hooke (England) – 1st Described the cell and known as father of cell-

biology.

•1676 Millington - Anthers function as male organs

•1694 Camerarius (Germany) - First to demonstrate sex in plants.

•1717 Fairchild – produced the first artificial hybrid, popularly known as

Fairchild ҆s mule, by crossing Carnation with Sweet William variety of Dianthus.

•1753 Linnaeus - Published "Species Plantarum". Binomial nomenclature of

plant taxonomy officially begins with his general list of plant species

•1761-66 Koelreuter (Germany) - Demonstrated that hybrid offspring received

traits from both parents and were intermediate in most traits.

•1779 Knight - Emphasized the practical aspects of hybrids.

•1801 Lamarck - given Theory of evolution through inheritance of acquired

characters .

•1819 Shirreff - Utilized pure line selection to develop a new oat cultivar

(released in 1824), and a new wheat cultivar (released in 1832)

•1831 Brown - Discovered the eukaryotic cell nucleus

•1837-38 Schleiden and Schwann - Developed the cell theory

•1859-89 Darwin - Published "Origin of Species"; and noted inbreeding,

sterility, and differences in reciprocal crosses

•1866 Mendel - Published "Experiments in plant hybridization"; discovered unit

factors (genes), segregation of F2, recombination of 2 or more genes, and

dominance of one allele over another; formulated the laws of inheritance

•1884 Strasburger - Demonstrated fertilization and showed the fusion of the 2

nuclei to form the zygote

•1899 Novaschin and Guignard - Discovered double fertilization of egg and

endosperm

•1899 Hopkins - Described ear to row selection method.

2. Mendelian era:-

•1900 Correns (Germany), DeVries (Holland) and Von Tschermak

(Austria) - Independently rediscovered Mendel̓s laws of heredity.

•Bateson- Introduced the terms "allelomorph", "homozygote", "heterozygote

", "F1" and "F2"

•1902 DeVries (Holland) - Proposed the mutation theory of evolution on his

experiments on Oenothera lamarckiana.

•Biffen (England) – on his studies on inheritance of studies on disease

resistance; found that stripe rust resistance was due to a single gene

•1903 Johannsen - Developed the pure line theory of selection

•1904 Hannig - Contributed to the idea of embryo culture

•1906 Bateson - Introduced the term "genetics“

•YULE – gave the initial idea of multiple factor hypothesis.

•1908 Nilsson- Ehle – given the explanation of multiple factor hypothesis for

Grain colour of Wheat.

•1908-09 Hardy (England) and Weinberg (Germany) – independently given

algebraic equation that describes the algebraic equation within a population,

also known as Hardy- Weinberg law.

•1914 Shull - Introduced the term "heterosis "

•Blakeslee - Discovered trisomics in Datura.

3. Post Mendelian era:-

•1927 Muller - Reported artificial mutations in animals by X-rays

•1928 Stadler - Described the mutagenic effects of X-rays in barley

•1929 McClintock - First to report and number 10 chromosomes in maize

•1931 Stern, Creighton and McClintock - Provided the cytological proof of

crossing-over

•1933 Rhoades - Discovered cytoplasmic male sterility in maize

•1944 Avery, MacLeod and McCarty - Described the transforming principle

and suggested that DNA, not protein, is the hereditary material

•1945 Hull - Proposed recurrent selection method

•1946 Comstock et al. - Suggested reciprocal (half-sib) recurrent selection

•1950 McClintock - Described the Ac-Ds system of transposable elements in

maize.

4. Modern era:-

•1952 Jensen - 1st suggested the use of multilines in Oats.

•1953 N.E.Borlaug – 1st outlined the method of developing multilines in

wheat.

•1955 Benzer – Based on his work on rII locus of T4 Bacteriophage he

gave the subdivisions of genes in cistron, recon and muton.

•1963 Vanderplank – developed the concept of vertical and horizontal

resistance.

•1964 N.E.Borlaug – developed the high yielding dwarf varieties of Wheat

which resulted in green revolution.

•1968 Donald – developed the concept of crop ideotype in wheat.

•1978 - Development of worlds 1st Rice hybrid (CMS based) for commercial

cultivation in China.

•1983 – Development of 1st transgenic (genetically engineered) plant of Tobacco

in U.S.A.

•1987 – Development of 1st transgenic cotton plant by Monsanto company in

U.S.A.

•1994 – Flavr Savr tomato was introduced by Calgene company of California. It

was the 1st commercially grown genetically engineered crop.

History of Plant Breeding in India

•1871- Government of India created the Department of Agriculture.

•1905- The Imperial Agricultural Research Institute was established in Pusa

(Bihar), this was the first Agricultural Research Institute in the country.

•1921- The Indian Central cotton committee was established.

•1929- Imperial Council of Agricultural Research was established in New Delhi.

•1936- Imperial Agricultural Research Institute shifted to its present location in

New Delhi.

•1956- Project for Intensification of Regional Research on Cotton, Oilseeds and

Millets (PIRCOM) was initiated in order to intensify research on these crops.

•1957- All India Coordinated Maize Improvement Project was started with

the objective of exploiting Heterosis.

•1961- First Maize hybrid was released (Ganga1, Ganga101, Deccan and

Ranjit)

•1964- First Sorghum hybrid (CSH-1) was released.

•1965- First Bajra hybrid (HB-1) was released.

•1991 – 1st pigeon pea hybrid (ICPH-8) was released from ICRISAT,

Hyderabad

Some indian plant breeders:-

•T. S. Venkatraman - he transferred thick stem and high sugar contents from

tropical cane ( Saccharum officinarum) to indian cane (Saccharum barberi).

this process is known as Noblisation of sugarcane.

•B. P. PAL – 1st director general of ICAR. He developed some superior

disease resistance variety of Wheat.

•M. S. Swaminathan – father of green revolution in India. He developed the

high yielding dwarf varieties of Wheat.

•Puskarnath – a famous potato breeder who developed several high yielding

varieties of potato.

•N. G. P. Rao – he is an eminent sorghum breeder and developed the worlds

1st hybrid of sorghum (CSH-1).

THANK YOU