This document provides an overview of population improvement methods for different crop types. It discusses breeding methods for self-pollinated, cross-pollinated, and vegetatively propagated crops. For cross-pollinated crops, which are the focus of population improvement, mass selection and progeny/family selection are described as the main intra-population and inter-population improvement strategies. Mass selection involves selecting superior plants within a population, while progeny selection evaluates the performance of individual plants' offspring. The document also gives examples of varieties developed using these methods.
Stability analysis and G*E interactions in plantsRachana Bagudam
Gene–environment interaction is when two different genotypes respond to environmental variation in different ways. Stability refers to the performance with respective to environmental factors overtime within given location. Selection for stability is not possible until a biometrical model with suitable parameters is available to provide criteria necessary to rank varieties / breeds for stability. Different models of stability are discussed.
It comprises on mating designs used in plant breeding programs. 6 basic mating designs are briefly explained in it with their requirements as well limiting factors...
Stability analysis and G*E interactions in plantsRachana Bagudam
Gene–environment interaction is when two different genotypes respond to environmental variation in different ways. Stability refers to the performance with respective to environmental factors overtime within given location. Selection for stability is not possible until a biometrical model with suitable parameters is available to provide criteria necessary to rank varieties / breeds for stability. Different models of stability are discussed.
It comprises on mating designs used in plant breeding programs. 6 basic mating designs are briefly explained in it with their requirements as well limiting factors...
Heterosis breeding
Heterosis or hybrid vigour or outbreeding enhancement
Types of heterosis
Genetic basis of heterosis
HYBRIDS
Development of inbreds
Combining ability
Types of hybrids
Single cross hybrid
Double cross hybrid
Triple cross hybrid
Top cross hybrid
SELECTION METHODS IN SELF-POLLINATED CROPS viz., mass selection, pureline sel...AMIT RANA Ph. D Scholar
MASS SELECTION
Mass selection is a method of breeding in which individual plants are selected on the basis of phenotype from a mixed population , their seeds are bulked and used to grow the next generation.
Selection cycle may be repeated one or more times to increase the frequency of favorable alleles - phenotypic recurrent selection.
PURELINE SELECTION
A pureline is the progeny of a single homozygous plant of a self-pollinated species. All the plants in a pureline have the same genotype and the phenotypic variation within a pureline is due to the environment alone and has no genetic basis. However, variation within a pureline is not heritable. Hence selection in a pureline is not effective. Johannsen (1903,1926), a Danish biologist, developed the concept of pureline theory working with Princess variety of French bean (Phaseolus vulgaris), which showed variation for seed size. From a commercial seed lot he selected seeds of different sizes and grew them separately. The progenies differed in seed size. Progenies from larger seeds produced larger seeds than those obtained from smaller seeds. This clearly showed that the variation in seed size in the commercial seed lot of princess variety had a genetic base. As a result selection for seed size was effective.
Introduction
PEDIGREE SELECTION
Pedigree selection is a widely used method of breeding self-pollinated species.
A key difference between pedigree selection and mass selection or pure-line selection is that hybridization is used to generate variability (for the base population), unlike the other methods in which production of genetic variation is not a feature.
The method was first described by H. H. Lowe in 1927.
Pedigree selection is a breeding method in which the breeder keeps records of the ancestry of the cultivar.
The base population is established by crossing selected parents, followed by handling an actively segregating population.
Documentation of the pedigree enables breeders to trace parent–progeny back to an individual F2 plant from any subsequent generation.
The breeder should develop an effective, easy to maintain system of record keeping.
Pedigree selection is applicable to breeding species that allow individual plants to be observed, described, and harvested separately.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Methods of crop improvement and its application in crosspollinated crops
1. DOCTORAL SEMINAR
ON
METHODS AND APPLICATIONS OF
POPULATION IMPROVEMENT
Presented by
Biswajit Sahoo
Ph.D. 1st year
DEPARTMENT OF GENETICS AND PLANT BREEDING
COA, RAIPUR, (C.G.)
2. INTRODUCTION
Population improvement was the earliest method applied to cross-
pollinated crops.
It deals with the improvement of crops and production of new crop
varieties which are far superior to existing types in all characters.
The result of improvement leads to higher yield, agronomically more
stable, resistant to diseases, insects, drought, frost, floods, alkaline and
saline conditions, improve the quality of produce such as size, colour,
shape, taste, nutritional value.
Different breeding methods are being used in different crops to improve
the genotype of crop based on their mode of pollination.
3. BASED ON THE MODE OF POLLINATION CROPS ARE CLASSIFIED INTO
Mode of pollination Example
Self pollination Rice, Wheat, Barley, Oats, Chickpea, Pea, Cowpea, Lentil,
Greengram, Blackgram, Soybean, Linseed, Brinjal,
Tomato, sesame, khesari, Sunhemp, Chillies, Okra,
Peanut, Mothbean, Common bean
Cross pollination Corn, Pearlmillets, Rye, Lucern, Radish, Cabbage,
Sunflower, Sugarbeet, Castor, Rape Seed, Safflower,
Spinach, Onion, Garlic, Turnip, Musk melon, watermelon,
Carrot, Coconut, Papaya
Often cross
pollination
Sorghum, Cotton, Triticale, Rai, Pigeonpea, Tobbaco, Jute
Vegetatively
propagated
Sugarcane, Coffee, Cocoa, Tea, Apple, Pears, peaches,
Cherries, Grapes, Almond, Pineapple, Banana, Cashew,
Strawberry, Mango, Cassava, Taro, Rubber, Sweet Potato
Source: Book: objective science of plant breeding by Phundan Singh
4. BREEDING METHODS FOLLOWED BASED ON MODE OF
POLLINATION
Self pollinated crops Cross pollinated crops Vegetatively propagated
crops
Plant Introduction Plant Introduction Plant Introduction
Mass selection Mass selection Clonal Selection
Pure line selection Recurrent Selection Mass selection
Pedigree method Synthetics Heterosis Breeding
Bulk method Composites Mutation Breeding
Single seed descent method Back cross method Polyploidy Breeding
Back cross method Heterosis Breeding Distant hybridization
Heterosis Breeding Polyploidy Breeding Transgenic Breeding
Mutation Breeding Distant hybridization
Polyploidy Breeding Transgenic Breeding
Distant hybridization
Transgenic Breeding
6. DIFFERENT TYPES OF GENETIC POPULATIONS IN
PLANT BREEDING
Population Brief Description Examples
Homozygous Non-segregating populations Pure lines, inbred lines, mass selected
autogamous varieties and multilines
Heterozygous Populations segregate on selfing F1 hybrids, composites, synthetics and
a clone
Homogeneous Genetically similar population Pure lines, inbred lines, F1 hybrids
progeny of a clone
Heterogeneous Genetically dissimilar population Land races, composites, synthetics and
multilines
Combinations
Homozygous and
Homogeneous
Genetically similar and non-
segregating population
Pure lines and inbred lines
Heterozygous and
Homogeneous
Genetically similar but
segregating on selfing
F1 hybrids between inbred lines and
progeny of clone
Homozygous and
Heterogeneous
Genetically dissimilar but non-
segregating populations
Multilines and mass selected varieties
in autogamous species
Heterozygous and
Heterogeneous
Genetically dissimilar but
segregating populations
Composites and synthetics
7. CHARACTERISTICS OF CROSS POLLINATED CROPS
Each genotype has equal chance of mating with all other
genotypes.
Individuals are heterozygous in nature.
Higher degree of inbreeding depression.
Wide adaptability and more flexibility to environmental changes
due to heterozygosity and heterogenity.
Cross pollination permits new gene combinations from different
sources.
Individuals have deleterious recessive gene which are concealed by
masking effect of dominant genes.
8. FOCUS OF BREEDING CP CROPS
Population Improvement
Heterozygosity
Quantitative Traits/Characters
To pre-dominate a desirable genotype in
population
Arising new genotypes (gene recombination)
9.
10. A BRIEF DESCRIPTION OF VARIOUS SELECTION SCHEMES FOR
POPULATION IMPROVEMENT
Selection scheme Brief description
Intra-population improvement For improvement within a population
A. Mass selection Selection based on phenotype of individual plants;
selected plants reproduce by open-pollination.
1. For one sex Inferior plants present in the population are detasselled;
open-pollination among the remaining plants.
2. For both sexes All plants in the population allowed to produce pollen;
open-pollination without any restriction.
3. Stratified Field divided into small plots of about 40 plants each;
selection within small plots; open-pollination without any
restriction; selection usually for one sex only.
4. Constiguous control Plants of a single genotype (single cross, inbred) used as
check and planted after every 2-4 hills for comparison;
check plants detasselled; other plants open-pollinate;
selection usually for one sex.
11. B. Family selection Selection based on means of individual plants progenies or
families.
1. Half-sib Plants within each family (individual plant progeny) half-sibs,
i.e. have one parent (usually the female) in common.
a. Ear-to-row families produce by open-pollination; selection within superior
families; no replicated trial; unrestricted open-pollination
among all the families
b. Modified ear-
to-row
As in ear-to-row; superior progenies identified by replicated
yield trial; pollen source: a random bulk of all the families
c. Half-sib
selection
As in the modified ear-to-row, but only superior progenies
planted in the crossing block and allowed to open-pollinate
d. Modified half-
sib
Half-sibs used for yield trial; S1 families from plants producing
superior half-sibs intermated through open-pollination
e. Broad base
test cross
Hail-sib families produced by crossing the selected plants to a
tester with a broad genetic base (parental or unrelated) used
for yield trial; S1 progenies from plants producing superior
half-sib families intermated (syn., recurrent selection for GCA)
f. Narrow based
test cross
As in the broad base testcross, but the tester has a narrow
genetic base (syn., recurrent selection for SCA)
12. 2. Full-sib Plants within each family are full-sibs; produce by mating the selected
plants in pairs.
a. full-sibs
intermated
Full-sibs used for yield trial; superior full-sibs intermated
b. S1 progenies
intermated
Full-sibs used for yield trial; S1 progenies from the plants producing
superior full-sibs intermated
3. Inbreds or selfed Families produced by selfing
a. S1
Families produced by one generation of selfing used for evaluation;
superior families intermated (syn., simple recurrent selection)
b. S2
Families produced by two generation of selfing used for evaluation;
superior families intermated
Inter-population
improvement
Two populations improved simultaneously for combining ability with
each other
A. Half-sib reciprocal
recurrent selection(HS-
RRS)
Reciprocal with half-sib progeny.
B. Full-sib reciprocal
recurrent selection (FS-
RRS)
Each selected plant in the population A and is selfed. Each selected
plant from A is test crossed with one selected plant from B. The test
cross progenies are evaluated in field trial. S1 families of plants from
A producing superior test cross progenies are intermated; the same is
done from B. Requires at least two ears/plant in one of the two
populations.
13.
14. MERITS
1. Selection is extreme simple and rapid.
2. Selection cycle is very short and only one generation.
3. Highly efficient to improve easily identifiable and high heritability characters like e.g.
plant height, size of the ear, date of maturity.
4. With proper care it effective to improve yield as well.
5. Most CP crops have a high additive component of genetic variance, which respond to
selection.
6. Extensive yield trials are not required as improved strain is likely similar to original
population.
Demerits
1. Selection based on the superiority is poor basis of selection
2. Both superior and inferior plants present because of open-pollination, so reduces the
effectiveness of selection.
3. High selection intensity reduces population size, leads to inbreeding depression.
15. STRATIFIED MASS SELECTION
Suggested by Gardner in 1961.
Also known as grid method of mass selection
Entire field is divided into small plots, each
having 40-50 plants.
Superior plants are selected in each small plot.
Seeds are selected and composited to raise the
next generation.
21. Merits of progeny selection
It is more dependable reflection of genotypic worth of the selected plants than
their phenotype.
It is more efficient improving yield ability of opv of maize
Avoid inbreeding depression if sufficient large amount of progenies are taken
and if the selected plants are not closely related.
Relatively simple and easy, but some modifications are complicated and tedious.
Demerits of progeny selection
Most progeny selection allowed to open-pollinate, so selection is based on
maternal parent only, which reduces the efficiency of the selection
Schemes are complicated and involve considerable work.
Selection cycle usually two year, i.e. each selection cycle takes twice as much as
mass selection.
22. RECURRENT SELECTION
It is defined as reselection generation after generation with
inbreeding of selects to provide for genetic recombination (Hull,
1945).
To increase frequency of favourable gene for quantitative
character/trait.
Identification of genotype superior for the specific quantitative
character being improved.
Subsequent intermating of superior genotypes to obtain new gene
combination.
Cycle may be repeated as long as superior genotypes possessing
gene for character of interest are generated.
23.
24. phenotypic Recurrent Selection
To improve plant’s quantitative characters based on visual observations,
physical measurement of character.
E.g. Oil content in corn and fibre strength in cotton.
Genotypic Recurrent Selection
Its the selection to improve a plant quantitative character based
on progeny performance as measured by test crosses, or by other
means, and is utilized to improve complex characters such as
combining ability in corn inbred lines
31. COMPARISON
Particular Recurrent selection for
GCA
Recurrent selection for
SCA
Application Used to increase polygenic
traits
Also used to increase
polygenic traits
Basis of selection Test cross performance Test cross performance
Tester used Heterozygous Homozygous
Effectiveness Incomplete dominance Complete and Over-
dominance
Condition of use Used when additive gene
action important
Non- additive gene action
important
Impact Used to improve GCA
characters
Improve SCA characters
34. MERITS OF RECURRENT SELECTION METHODS
Efficient method to increase the frequency of the superior genes in a
population.
It helps in maintaining the high genetic variablility in a population
due to repeated intermating of heterozygous population.
The selection is based on the test cross performance and only
selected plants are allowed for inter-mating.
deMerits of recurrent selection methods
Involves lots of selection, crossing and selfing work.
Permits selfing which leads to loss of genetic variability.
It is not directly used for the development of new varieties.
35. COMPARISON AMONG DIFFERENT RECURRENT
SELECTION SCHEMES
1. When dominance is incomplete, RRS and RSGCA would be comparable in
their effectiveness, and both will be superior to RSSCA.
2. When dominance is complete, the three methods would be equally
effective.
3. When dominance is over-dominance, RRS and RSSCA would be equally
effective, but both would be more effective than RSGCA.
4. The above relationships are expected when there epistasis, multiple alleles
and linkage disequilibrium are absent.
5. In most crop species epistasis is important and linkage disequilibrium and
multiple alleles are likely to be present. In such cases, RRS would be
superior to RSGCA and RSSCA.
6. In all practical situations, RRS would be superior to RSGCA and RSSCA.
36. FULL-SIB SELECTION
1. With full-sib selection, crosses are made between selected pairs of plants
in the source population, with the crossed seed used for progeny tests and
for reconstituting the new population.
2. First season
Cross 150 to 200 pairs of plants selected from the source population.
Reciprocal crosses may be made to provide a larger quantity of crossed
seed.
3. Second season
Grow a replicated progeny test with seed from each pair of crosses
keeping the remnant crossed seed.
4. Third season
Reconstitute the source population by mixing equal quantities of
remnant crossed seed from 15 to 20 paired crosses with superior
progeny performance, and grow in isolation with open pollination to
obtain new gene combinations.
38. SELECTION FROM S1 PROGENY TEST
1. S1 refers to the progeny following self pollination of plants in
an open pollinated population, or in the F2 following a cross.
2. First season
Select 50 to 100 plants from a source nursery prior to
flowering.
Self pollinate and harvest selfed seed from selected S0 plants.
3. Second season
Grow replicated S1 progeny trial, keeping remnant seed (S0)
seed.
4. Third season
Composite equal quantities of remnant seed from the So
plants with superior progenies, and grow the seed
composite in isolation to obtain new gene combinations.
40. SYNTHETIC VARIETIES
A variety produced by crossing in all combinations a number
of lines that combine well with each other is known as a
synthetic variety.
It is maintained by open pollination in isolation.
The lines may be inbreds, clones, and OPV.
The end product of recurrent selection, which are already
tested for GCA are generally, used to constitute synthetic
varieties.
5-8 good GCA inbreds are used for synthetic Variety.
44. COMPOSITES
Mixing the seeds of several phenotypically outstanding lines
produces a composite variety.
Outstanding lines may be germplasm inbreds, varieties,
hybrids, advance generation lines.
Rarely tested for general combining ability.
Maintained by open pollination in isolation.
Farmers can use their own seed for 3 ton 4 years.
45. PROCEDURE
Select Lines producing desirable characters
(selected lines should be like earliness, insect resistance, drought and frost resistance)
Seeds of desirable characters mix together
Random mating for 4-5 generations
Uniform populations are tested in replicated trials
High yielding stable type can be released as variety
48. CONCLUSION
The improved population resulting from
various schemes are excellent sources of
good inbred lines, such populations may
be expected to become increasingly
important in the future.
49. QUESTION
Is recurrent selections applicable to self
pollinated crop or not, justify your
answer ?