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

Allopolyploidy

  • Allopolyploids have genomes from two or more species production of allopolyploids has attracted cons adorable attention; the aim almost always was creation of new species.
  • Some success has been evident from the emergence of triticale. Raphano brassica and allopolyploids of forage grasses.

 

Morphological and extological features of allopolyploids

  1. Allopolyploids combine the morphological and physiological characteristics of the parent species but it is very difficult to predict the precise combination of characters that would appear in the new species.
  2. Many allopolyploids are apomictic

Ex : Tulips, Solanum

  1. The chromosome pairing in the new species depends upon the similarities between the chromosomes of the parental species. Chromosomes with such similarities are known as homoeologous chromosomes. After chromosome doubling, the allopolyploid would have two homologous chromosomes for each chromosome present in the F1 hybrid, comparable to the diploid species. Such allopolyploid is referred as amphidiploid or Allotetraploid.
  2. Fertility of Allopolyploids can be improved by hybridization and selection.

 

Application of allopolyploidy in crop improvement

  • Alloployploidy has three major applications in crop improvement : (1) as bridging species in the transfer of characters from one species into another, (2) in the production of new crop species, and (3) for widening the genetic base of existing allopolyploid crop species.

 

  • The promising alloplyploids are Raphanobrassica, the triploid (AAC) obtained by crossing B. napus (AACC) with B. campestris (AA), allopolyploid clovers, Festuca-Lolium hybrids and some species hybrids in Rubus and Jute (Corchorus sp.,). In Raphanaobrassica, the breeding objectives are to combine the hardiness of B. oleracea with quick growth and disease resistance of fodder radish. The problems of Raphanobrassica are the same as those of triticale. i.e., low fertility, cytogenetic and genetic instability and leafy rape-like plants that do not produce bulbs. There is evidence that hybridization and selection at the polyploidy level would be effective in improving Raphanobrassica.

 

  • In cassava the triploids developed by crossing tetraploids and diploids, have been reported to be promising and it therefore seems possible to improve cassava by producing new chromosomal lines, in which the chromosome number does not go beyond an optimum level.The triploid plants derived from OP-4 (2x) X S-300 (4x) and OP-4(2x) X H-2304 (4x) consistently produced roots with high dry matter in the seedling and succeeding clonal generations, which ranged from 34 to 43%. Some of the triploids recorded high starch content from the eighth month onwards, being significantly higher than that of the control. Among these, the triploid 76-9 had a yield similar to that of H- 2304, the released cultivar, at CTCRI.

 

  • The amphidiploids B.napus (AACC) crosses very easily with B. campestris (AA) to produce the triploid (AAC), which has some desirable features. The triploid is produced so easily that it may be used as a hybrid variety, a special case of hybrid varieties produced by crossing two different species.
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