Crop wild relatives (molecular breeding and bioinformatics) .pptx
1. DEPARTMENT OF GENETICS AND
PLANT BREEDING
FACULTY OF AGRICULTURE
ANNAMALAI UNIVERSITY
GPB 517 GERMPLASM CHARACTERIZATION AND
EVALUATION
Submitted by,
SATHISH KUMAR M,
1st YR M..Sc .,Agricultutre GPB
2. Using of CWRs in Crop Improvement
• Crop wild relatives (CWR) are taxa closely related to crops and are
defined by their potential ability to contribute beneficial traits for
crop improvement; for example, to confer resistance to pests and
diseases, improve tolerance to environmental conditions such as
extreme temperatures, drought and flooding, and to improve
nutrition,flavour, colour, texture and handling qualities
3. CWRs definition
• A working definition of a CWR based on the Gene Pool concept or, in the
absence of crossing and genetic diversity information, the Taxon Group
concept , has been proposed.
• ‘‘A crop wild relative is a wild plant taxon that has an indirect use derived
from its relatively close genetic relationship to a crop; this relationship is
defined in terms of the CWR belonging to gene pools 1 or 2, or taxon
groups 1 to 4 of the crop’’
4. Why are CWR threatened?
• Expansion of the human population (which leads to the unequal and
unsustainable use of natural resources, and is the basis of all other threats);
• Climate change which is expected to directly affect the cropping patterns
and extinction of wild plant species, particularly in drier regions where certain
CWR may already be at the edge of their distribution;
5. .
• Habitat destruction, degradation, homogenisation and fragmentation;
• Changes in agricultural practices, soil and land use;
• Use of pesticides and herbicides;
• Over-exploitation (excessive extraction from the wild of timber, fuel wood,
medicinal and horticultural plants, overgrazing, excessive tourism, etc.);
• Introduction of exotic species (weeds, pests and diseases that compete with,
hybridise with, cause physical or biological damage to, or kill native species);
• Natural calamities (floods, landslides, soil erosion, etc.);
• Lack of education and awareness of the importance of CWR and the need
to conserve them;
• War and political instability;
• Lack of conservation action for CWR; Environmental mismanagement.
6. CWRs in Crop Improvement
• Numerous efforts have been made to utilize the genetic diversity in CWRs to
improve various crop species .
• These efforts have been concentrated primarily on certain crop species,
including wheat, barley, rice, and tomatoes.
7. .
Possible reasons for the greater use of CWRs in only certain crops include,
(i) cross compatibilities
(ii) the taxonomic relationship between crops and their close wild species
(iii) fertility in the F1 and subsequent progeny,
(iv) availability or conservation of CWRs
(v) exploration and utilization of wild germplasms
(vi) regional financial support based on local need and geographic distribution
of CWRs.
15. APPROACHES USAGES ADVANTAGES SHORTCOMINGS
Genomics Germplasm
resource
evaluation and
identification;
heterosis
prediction;
linkage and
association
mapping; marker-
assisted breeding
High-throughput;
Time-saving
Costly;
Bioinformatics
skills required;
Difficulties in
assembly of
polyploid
genomes
16. APPROACH USAGE ADVANTAGES SHORTCOMINGS
Transcriptomics
and proteomic
Quantification of
expression
variants response
to environment
stress; updating
genome annotatio
Generating
numerous
candidate genes;
regulatory network
identification;
more useful when
combined with
linkage analysis
Difficult to
pinpoint causal
genes or proteins;
high cost for
proteomics
17. APPROACHES USAGES ADVANTAGES SHORTCOMINGS
Metabolomics Metabolic profiling Quantification of
target or global
metabolite
Costly;
limited annotation
data; low
heritability;
requiring chemical
and statistical skill
Transgenesis Genetic
modification
Transfer b/w
noncrossable
species
Subject to GMO
regulations;foreign
genes
18. APPROACHE USAGE ADVANTAGES SHORTCOMIN
GS
Advanced
introgression lines
Genetic mapping;
introgression
breeding
Traditional
breeding;
introducing
multigenic trait
Need supports by
molecular DNA
markers;
crosscompatible;
laborious and
tedious
backcrossing
Genome editing GM Precise and
predefined
modification
Might subject to
GM regulatory
regime; public
acceptance
19. APPROACH USAGE ADVANTAGES SHORTCOMIN
GS
Cisgenesis/
Intragenesis
GM enes from species
itself or crossable
species; stacking
multiple genes;
public acceptable;
avoid linkage drag
Might require
traditional breeding
step
High-throughput
phenotyping
Phenotyping High-throughput;
real-time;
multidimensional
High cost;
mathematical and
statistical skill
required
