Course Content
Introduction to plant breeding
0/5
Introduction
Scope of plant breeding (Future Prospects)
Undesirable effects
History of plant breeding
Scientific contributions of eminent scientists
Domestication, plant introduction, and acclimatization
0/6
Acclimatization
Plant Introduction
Procedure of Plant Introduction
Purpose of plant introduction
Merits of Plant Introduction
Germplasm Collection
Modes of reproduction and pollination control
0/6
Mode of reproduction
Categories of mode of reproduction
Pollination
Mechanisms promoting self-pollination
Genetic Consequences of Self-Pollination
Genetic Consequences of Cross-Pollination
Qualitative and quantitative characters (qualitative and quantitative characters in crops and their inheritance)
0/2
Introduction
Role of the environment in Quantitative Inheritance
Biometrical techniques in plant breeding (assessment of variability, aids to selection, choice of parents, crossing techniques, genotype-by- environment interactions)
0/3
Introduction
Components of Genetic variance
Things to remember
Selection in self-pollinated crops (progeny test, pureline theory, origin of variation, genetic advance, genetic gain)
0/5
Progeny test
Pureline selection
General procedure for evolving a variety by pureline selection
Advantage of pureline selection
Origin of variation in pure lines
Hybridization techniques and its consequences (objectives, types, program, procedures, consequences)
0/4
Introduction
Some terminologies
Types of hybridization
Pre-requisites for hybridization
Genetic composition of cross-pollinated populations (Hardy-Weinberg law, equilibrium, mating systems)
0/4
Hardy-Weinberg law
Proof of Hardy-Weinberg law
Example of Hardy-Weinberg law
Factors affecting equilibrium frequencies
Selection in cross-pollinated crops (response and gain from selection, variability)
0/5
Introduction
MASS SELECTION
Recurrent selection
Procedure for Reciprocal recurrent selection
Half-sib and full-sib selection with progeny testing
Heterosis and inbreeding depression
0/5
Heterosis
Manifestations of Heterosis
Inbreeding depression
Degrees of inbreeding depression
Use of heterosis
Mutation breeding (types, use of mutagens, application)
0/8
Introduction
Classification of mutations
Characteristic feature of mutations
Procedure for irradiation
Selection of the variety and dose of mutagen
Mutation breeding for polygenic traits
Applications of Mutation Breeding
Advantages of mutation breeding
Polyploidy in plant breeding (aneuploidy, euploidy, allo- and autoploidy, applications)
0/6
Introduction
Origin and production of doubled chromosome numbers
Morphological and cytological features of auto polyploids
Application of Autopolyploidy in Crop improvement
Allopolyploidy
Limitations of Allopolyploidy
Breeding methods in self-pollinated crops (Mass, Pure line, Pedigree, Bulk, Backcross, etc)
0/5
Mass Selection
Bulk Method
Pedigree Method
Single Seed Descent
Backcross
Clonal selection
0/5
Clonal Selection
Advantages and disadvantages of clonal selection
Problems in Breeding asexually propagated crops
Genetic variation within a clone
Clonal degeneration
Release of new varieties
0/5
Introduction to Variety
Norms for Release of New Variety
Development of New Variety
Institutions Related with Release of Variety
Variety Release Procedure
Quality seed
0/4
Introduction
Importance of quality seed
Major seed quality characters
Characteristics of good quality seed
Breeding for pest resistance
0/3
Pest includes
Defense mechanisms of host against pathogen/parasite
Breeding for resistance
Intellectual property right
0/4
Introduction
Objectives
Types of Intellectual Property
Policy objectives favoring IPRs in new plant varieties
Learn Introductory Plant Breeding with Rahul
About Lesson

Mass Selection

  • May or may not include hybridization
  • Make IP selections based on single, ideal or desirable phenotype and BULK seed
  • May repeat or go directly to performance testing

Mass Selection has 2 important functions:

  1. Rapid improvement in land-race or mixed cultivars
  2. Maintenance of existing cultivars (sometimes purification)
  • Success depends on extent of variation and h2 of the traits of interest
  • Land races make an ideal starting source

 

Steps of Mass selection

A) Initial selection:

  • Can be either a positive or a negative selection
  • Negative screening: A screening technique designed to identify and eliminate the least desirable plants.
  • positive screening: which involves identifying and preserving the most desirable plants.

 

 

 

B) 1st Year:

  • Select plants with respect to height, maturity, grain size, and any other traits that have ‘production’ or ‘acceptability’ issues
  • Bulk seed (may ‘block’ these bulks if wide variation is present for certain traits; e.g. height)
  • May be able to use machines to select. i.e. Harvest only tall plants, or save only large seed passed through a sieve.

 

C) 2nd Year:

  • MS really only takes 1 yr because selected seed represents a mixture of only the superior pure lines that existed in the original population
  • However, additional rounds of selection and bulking will allow for evaluation under different environments, disease and pest pressures.
  • Also, multiple years will allow you to compare performance with established cultivars over years and environments.

 

Objectives of Mass Selection

  1. To increase the frequency of superior genotypes from a genetically variable population
  2. Purify a mixed population with differing phenotypes
  3. Develop a new cultivar by improving the average performance of the population

 

Disadvantages of Mass selection

  1. Selection based on phenotypic performance; not effective with low h2 traits
  2. Without progeny testing, heterozygotes can be inadvertently selected
  3. Population cannot realize maximum potential displayed by the ‘best’ pure line, due to bulking
  4. Final population is not as uniform as those developed through pure-line selection
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