This document discusses crop ideotypes, which are conceptual plant models designed with specific ideal traits. An ideotype is defined as a plant type expected to maximize yield of a desired product. There are three main types of ideotypes: isolation, competition, and crop. When developing an ideotype, breeders consider the target environment, quality factors, agronomic practices, and use simulation models. Ideal traits include efficient resource use, sensitivity to management, and high harvest index. Examples of crop ideotypes described include short-statured, high-tillering rice and wheat ideotypes, and maize ideotypes with efficient photosynthesis and grain filling. The multistep process of ideotype breeding aims to develop cultivars with

1. CROP IDEOTYPE CONCEPT AND ITS
APPLICATIONS IN PLANT BREEDING
Varsha p vengilat
2017600823

2. • Alternative breeding strategy.
• Concept by Donald in 1968.
• Literal meaning: ‘A form denoting an idea’
• Definition: A crop ideotype is a plant model,
which is expected to yield a greater quantity or
quality of grain, oil or other useful product
when developed as a cultivar.
• Synonyms: model plant type, ideal model plant
type and ideal plant type.

3. Types of ideotype
• Isolation Ideotype- performs best when space planted.
- lax, free tillering, leafy spreading
plant in case of cereals.
• Competition Ideotype- in gentically heterogenous
populations.
-tall, leafy, free tillering plant
(cereals)
• Crop Ideotype- Best at commercial crop densities; a
poor competitor.

4. Development of ideotypes
Following knowledge while developing ideotype:
• Target area and target environment
• Quality considerations
• Current agronomic practices
• Adequate information
• Simulation models can be used as aids

5. Characteristics of a crop ideotype
• A weak competitor
• Efficient in utilizing environmental resources
• Sensitive to cultural practices
• Include morphological and physiological
characteristics that result in high harvest index
• Should be grown in a weed free envt
• Planned selection done for features of crop ideotype

6. Ideotypes of selected crops
RICE
First introduced by Matsushima in 1957, later by Jennings.
Ideotype for dwarf rice(By Chandler):
 Shorter culm length.
 Greater culm diameter
 Lower relative internode elongation under
 heavy nitrogen application
 Short erect leaves,medium length
 High tillering capacity
 More panicles/m2

7. WHEAT
Proposed by Donald(1968)
Short strong stem
Erect leaves
Few small leaves
Large, erect ear
Presence of awns
Single culm
Reduced height
Photoperiod insensitivity
Rust resistance etc.

8. MAIZE
By Mock and Peacre(1975)
 Stiff vertically oriented leaves
above,
and horizontal leaves below
 Max. photosynthetic efficiency
 Efficient translocation
of photosynthates
 Short interval between pollen
shed and silk emergence
 High prolificacy
 Grain filling period should be as
long as possible
 Cold tolerance

9. COTTON

11. PULSES
Determinate plant type
Erect and upright plant
Early vigour, early flowering and synchronous
maturity
Pod bearing from well above the soil surface
More pods/plant & no. of seeds/pod
Hgh Harvest Index
Yield stability

12. STEPS IN IDEOTYPE BREEDING
• Development of conceptual Model
• Selection o base model
• Incorporation of desirable traits
• Selection of Ideal Plant type

13. MERITS
• Effective method of enhancing yield. It exploits both morphological and
physiological variation.
• Provides solution to several problems at a time like disease, insect and
lodging resistance, maturity duration, yield and quality .
• Genes for specific traits can be introgressed from unimproved to
improved gene pool to develop desirable variability for the trait.
• Efficient method of developing cultivars for specific or environment.
• An effective method of breaking yield barriers through the use of
genetically controlled physiological variation for various characters
contributing towards higher yield.

14. LIMITATIONS OF IDEOTYPE BREEDING
• Incorporation of several desirable morphological and
physiological and disease resistance traits from different
sources into a single genotype is a difficult task.
• A slow method of cultivar development
• Changes with change in knowledge, new requirements,
national policy, etc.