The document outlines the objectives of plant breeding, which include: 1. Developing varieties with higher yields, improved quality, and resistance to diseases and insects. This will make crops more profitable. 2. Adapting crops to different environments by modifying characteristics like maturity duration, photosynthetic responses, and tolerance to abiotic stresses. 3. Breeding desirable agronomic traits like plant height, tillering, and growth habit to suit various growing conditions and agricultural systems. The overall goal is to breed well-balanced, high-yielding varieties suited to local growing conditions and farmer needs.

1. OBJECTIVES
OF
PLANT BREEDING
By :-
E.Chethan Swamy
B.Sc.(Agriculture)

2. Plant Breeding :
 Plant Breeding aims to improve the various characteristics
of plants so that they become more desirable agronomical
and economically. Thus the chief objective of plant breeding
is to develop such improved varieties of the crop plants that
will be commercially successful.
 Generally a successful variety is one with a total balance of
traits that makes it more profitable for the growers than
any other one they might choose
 Therefore, specific objectives would vary greatly depending
on the crop and region. Some of the main objectives of plant
breeding may be summarised here.

3. Objectives of Plant Breeding :
1. Higher Yields
2. Improved Quality
3. Disease and insect resistance
4. Change in maturity duration
5. Agronomic characteristics
6. Photo and thermo sensitivity

4. Objectives of Plant Breeding :
7. Synchronous Maturity
8. Non-shattering
9. Determinate Growth
10.Dormancy
11.Moisture Stress and Salt Tolerances
12.Elimination of Toxic substances

5. 1. High Yields :
 Most of the breeding programmes aim at higher crop yields.
In fact, higher yields will always remain one of the main
objectives of the breeding programme. This is achieved by
developing more efficient genotypes, e.g., Hybrid varieties.
 The quality of the plant produce determines its suitability for
various uses therefore quality is an important aspect for plant
breeders. E.g., milling and baking quality in wheat(Triticum
aestivum) and cooking quality in Rice (Oryza sativa)
2. Improved Quality :

6. 3. Disease and Insect Resistance :
 Resistant varieties offer the cheapest, the most convenient,
and environmentally safe method of disease and insect
management. In some cases, they offer the only feasible
means of control e.g., rusts in wheat. Resistant varieties not
only increase production but also stabilise it.
 Breeding for early maturing crop varieties, or varieties
suitable for different dates of planting may be important
objectives in many crops. This would permit a new crops
rotations and often extend the crop area. For example, the
development of wheat varieties suitable for late planting has
permitted rice-wheat rotation.
4. Change in Maturity Duration :

7. 5. 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 the lodging resistance and fertilizer
responsiveness.
 Development of photo insensitive and thermo insensitive
wheat, and photo insensitive rice varieties has permitted their
cultivation in new areas. Rice is now cultivated in Punjab
while wheat is major Rabi crop in west Bengal. In case of
wheat, photoperiod insensitivity is due to genes ppd1 and
ppd2 which show polymeric gene action.
6. Photo- and Thermo Sensitivity:

8. 7. Synchronous Maturity :
 Synchronous maturity is highly desirable crops like Mung
(Vigna radiata), where several pickings are necessary
 This feature would be of great value in a crop like mung
where shattering is a major problem in case of many
commercial varieties
8. Non-shattering Characteristics :
9. Determinate Growth :
 Development of varieties with determinate growth habit is
desirable in crops like mung, pigeon pea(Cajanus cajan),
cotton(Gossyipium Spp.).

9. 10. Dormancy :
 In some crops, seeds germinate even before harvesting if there
are rains at the time of maturity e.g., mung, barley etc. A
period of dormancy in such crops would check the losses due
to preharvest rains. But in some crops, it may be desirable to
remove dormancy.
 Development of varieties for rained areas and for saline soils
would be helpful in increasing the crop production in India.
 The major proportion of calcium up to 70% of cropped area
and there are 7 to 20 million hectares are salt affected (Saline)
Soils.
11. Moisture Stress and Salt Tolerance :

10. 12. Dormancy :
 Some crops have the toxic substances, which must be
eliminated to make them safe for the consumption. For
example, Khesari (lathyrus sativus) seeds have a neurotoxins,
β-N-oxalyl-α,β-diaminopropionic acid(BOAA) that causes
paralysis of lower limbs. Similarly, brassica oil has erucic
acid, which is harmful to human health. Removal of such
toxic substances would increase the nutritional value of these
crops.
Others :
 Traditionally maize is a kharif crop. But scientists are now
able to grow maize as Rabi and Zaid crops.