COLLEGE OF NATURAL SCIENCES

DEPARTMENT OF PLANT SCIENCES, MICROBIOLOGY & BIOTECHNOLOGY

GENETIC RESOURSE CONSERVATION

QUESTION 5

AWORI ANNA 23/U/07080/PS

NAMBALIRWA BENITAH 23/U/1104
AYELLA JOHNATHAN BONGOMIN 23/U/07171/PS
KWEHAYO PRAISE 23/U/0657
Germplasm, Plant and Animal Genetic Resources and Their Diversity
Germplasm refers to the genetic material of an organism that can be used for breeding
purposes.
This can include seeds, genetic material, and other plant tissues that contain the essential
genetic information for a particular species.
Germplasm is important for maintaining biodiversity and for developing new crop
varieties that are resistant to diseases, pests, and environmental stresses.
It is often stored in gene banks or seed banks to preserve genetic diversity and ensure the
future availability of important plant species.
Plant Genetic Resources:
Plant genetic resource refers to any plant material, including seeds, tissues, and whole
plants, that contains genetic information and is utilized for research, conservation,
breeding, or other purposes.
These resources encompass the genetic diversity within plant species, varieties, landraces,
and wild relatives, which are conserved, managed, and utilized to improve agricultural
productivity, resilience to environmental stresses, and overall food security. Plant genetic
resources are essential for crop improvement efforts, biodiversity conservation, and the
sustainable management of agricultural systems.
Crop Diversity: Crop genetic resources play a crucial role in ensuring food security and
providing resistance to diseases and environmental stress. Crop diversity includes
different varieties of crops that have adapted to various climates and soils. For example,
within the maize species, there are thousands of different varieties with diverse traits such
as drought tolerance, pest resistance, and nutritional content.
Wild Relatives: Wild relatives of cultivated crops are important sources of genetic diversity.
They can provide valuable traits like disease resistance, drought tolerance, and improved
nutrient content. An example is the wild tomato species which has been used to improve
cultivated tomato varieties by introducing disease resistance genes.
Landraces: Landraces are traditional varieties of crops that have been developed over
centuries by farmers. They often possess unique genetic traits adapted to specific local
environments. An example is the Himalayan red rice landrace, which is adapted to high
altitudes and has unique nutritional properties.
Animal Genetic Resources: Animal genetic resources refer to the diversity of animal
species, breeds, populations, and their genetic material, which are conserved, managed,
and utilized for various purposes including food production, research, and cultural
heritage preservation.
These resources encompass the genetic diversity within livestock species such as cattle,
sheep, goats, pigs, poultry, and other domesticated animals, as well as indigenous or local
breeds adapted to specific environmental conditions and human management practices.
Animal genetic resources play critical roles in maintaining the resilience, productivity, and
sustainability of livestock production systems, as well as in preserving genetic diversity
and cultural heritage associated with traditional animal husbandry practices.
Conservation and sustainable management of animal genetic resources are essential for
addressing challenges such as climate change, disease outbreaks, and genetic erosion,
thereby ensuring global food security and biodiversity conservation and their genetic
material, which are conserved, managed, and utilized for various purposes including food
production, research, and cultural heritage preservation.
These resources encompass the genetic diversity within livestock species such as cattle,
sheep, goats, pigs, poultry, and other domesticated animals, as well as indigenous or local
breeds adapted to specific environmental conditions and human management practices.
Animal genetic resources play critical roles in maintaining the resilience, productivity, and
sustainability of livestock production systems, as well as in preserving genetic diversity
and cultural heritage associated with traditional animal husbandry practices.
Conservation and sustainable management of animal genetic resources are essential for
addressing challenges such as climate change, disease outbreaks, and genetic erosion,
thereby ensuring global food security and biodiversity conservation.
Breeds Diversity: Domestic animal breeds have been selectively bred for various purposes
such as meat production, milk production, and draft power. Each breed has unique genetic
traits that make them well-suited for specific environments or production systems. For
example, the Nguni cattle breed in Southern Africa is known for its adaptability to harsh
environments and disease resistance.
Indigenous Breeds: Indigenous animal breeds are adapted to local environmental
conditions and are often well-suited for traditional farming systems. These breeds play a
vital role in maintaining biodiversity and preserving valuable genetic traits. An example is
the Icelandic sheep breed, which is well-adapted to cold climates and has unique wool
qualities.
Centers of Origin & Diversity
A center of origin refers to a geographical area where a group of organisms, either
domesticated or wild, first developed its distinctive properties.
These areas are crucial because they mark the birthplace of specific species or crops.
In the context of agriculture, centers of origin are where crop plants originally originated.
Nikolai Vavilov, a renowned Russian botanist, pioneered the study of centers of origin. He
proposed that plants were not randomly domesticated worldwide but had specific regions
where domestication began.
These regions are known as Vavilov Centers (or Centers of Diversity). They are crucial for
understanding the origins of crop plants, locating wild relatives, and identifying new
genes.
Vavilov’s scheme evolved over time, with varying numbers of centers identified. Some
notable ones include:
Chinese Center: Considered one of the earliest and largest independent centers of origin
for cultivated plants, it encompasses regions in China.

Himalayan Center: Also known as the Indian center of origin, it includes the Himalayan
Mountain range. Many crops have their roots in this region.

Mediterranean Center: This center spans the borders of the Mediterranean Sea. It has
contributed to the domestication of various crops, including olives, grapes, and wheat.

Abyssinian Center: Encompassing Ethiopia and parts of Somalia, this region is significant
for crops like coffee and teff1.

Central Asian Center: Central Asia, including areas around the Caspian Sea, has been a
hub for crop diversity. Barley, wheat, and other grains have origins here.

South American Center: The Andes Mountains and surrounding regions are home to crops
like potatoes, quinoa, and tomatoes.

Mexican Center: Mexico is where maize (corn) was first domesticated. Other crops like
beans and squash also have their origins here.
North American Center: This center includes parts of the United States and Canada.
Sunflowers and cranberries are among the crops originating from this region.
West African Center (discovered after Vavilov’s time): West Africa has contributed to the
diversity of crops such as yams, millet, and sorghum.

Beyond plants, centers of origin apply to animals as well. However, pinpointing specific
centers for all animals is more complex due to their diverse habitats and evolutionary
histories.
Some general centers of origin for animal groups include:

Africa: Often considered a center for human evolution and the origin of many mammal
species.
South America: Known for diverse bird species, primates, and unique fauna like capybaras
and jaguars.
Southeast Asia: Rich in biodiversity, including various reptiles, amphibians, and insects.
Australia: Home to marsupials, monotremes (such as the platypus), and unique bird
species.
Madagascar: Famous for its lemurs and other endemic wildlife.
Galápagos Islands: Associated with Charles Darwin’s observations on adaptive radiation.
Arctic and Antarctic Regions: Vital for marine life and polar adaptations.
These centers of origin represent the rich tapestry of human ingenuity and the intricate
relationship between people and plants

Centers of Diversity:
Center of diversity refers to a location where vast genetic variability for a crop and its
wild species is found.
In other words, it’s a place where a particular crop exhibits a wide range of genetic traits
and variations.
Centers of diversity are essential because they serve as reservoirs of genetic resources.
These areas allow for the adaptation and evolution of crops over time.
Interestingly centers of diversity may or may not be the same as centers of origin.
For instance, while the Andes is a center of origin for potatoes, the Middle East is a center
of diversity for wheat.
Crop Genetic Diversity:
Crop genetic diversity refers to the rich variety of genes found in different crop species.
These genes are essential for creating diverse plant varieties that can adapt to various
environmental conditions and human needs.
Centers of Diversity: These are regions where crop genetic diversity is concentrated. They
serve as reservoirs of unique land races (locally adapted varieties) and their wild relatives.
These centers are typically located in the developing world.
Examples of major food crops and their centers of diversity:
Wheat and barley: Originated in the Near East.
Soybeans and rice: Came from China.
Sorghum, yams, and coffee: Originated in Africa.
Potatoes and tomatoes: Originated in the Andes of South America.
Maize: Originated in South and Central America.
Farmers in these regions continue to cultivate local land races and preserve wild relatives,
ensuring the continuation of crop genetic diversity .
Animal Genetic Diversity:
Animal genetic diversity is equally crucial for agriculture and food security.
Livestock: Different breeds of cattle, sheep, goats, and poultry have their origins in specific
regions.
Wild Relatives: These are closely related species that survive in the wild and contribute
to the genetic diversity of domesticated animals.
By maintaining and nurturing animal genetic diversity, we can enhance livestock
productivity and adapt to changing conditions
In conclusion, these centers of origin provide valuable insights into the origins, diversity,
and evolution of both plants and animals across our planet. Centers of origin represent
the birthplaces of crops, while centers of diversity harbor the rich genetic diversity
necessary for crop adaptation and improvement.

Molecular Tools or Genetic Resource Conservation

Genetic resource conservation is a crucial aspect of ensuring the sustainability of
biodiversity and the protection of valuable genetic material. Molecular tools have
revolutionized the field of genetic resource conservation by providing scientists with
advanced techniques to study and preserve genetic diversity in various species. These
tools offer a deeper understanding of the genetic makeup of populations, allowing for
more effective conservation strategies to be developed and implemented.
One of the key molecular tools used in genetic resource conservation is DNA sequencing.
DNA sequencing allows scientists to determine the exact sequence of nucleotides in an
organism's genome, providing valuable information about its genetic diversity and
evolutionary history. This information can be used to identify important genetic traits that
may be at risk of being lost and develop targeted conservation strategies to preserve
them.
Another important molecular tool in genetic resource conservation is microsatellite
markers. Microsatellite markers are highly variable regions of DNA that can be used to
study genetic diversity within populations and assess the genetic structure of different
populations. This information is essential for understanding the genetic health of
populations and designing effective conservation plans to maintain genetic diversity.
Genomic sequencing is also a powerful molecular tool that has been increasingly used in
genetic resource conservation. Genomic sequencing allows for the analysis of an
organism's entire genome, providing detailed insights into its genetic makeup and
enabling the identification of important genetic variations that may be critical for
adaptation and survival. This information is crucial for developing conservation strategies
that focus on preserving genetic diversity and maintaining population viability.
DNA barcoding is a powerful molecular tool for genetic resource conservation, particularly
in species identification and taxonomy. It involves comparing short, standardized
segments of DNA (barcodes) between species to determine if they share enough
differences to warrant separate species status. DNA barcoding offers several advantages,
such as speed, accuracy, and the ability to analyze small tissue samples without destroying
the organism. However, it faces challenges regarding the development of universally
applicable barcodes and the interpretation of results from closely related species. Multi-
locus barcodes are increasingly employed to account for variations in evolutionary rates
and selective pressures among genes. DNA barcoding plays a crucial role in wildlife
forensics, biodiversity assessment, and conservation planning.
PCR (polymerase chain reaction) is a molecular biology technique that is used in genetic
resource conservation. PCR makes it possible to amplify billions of copies of a specific
piece of DNA from the genome with very few starting copies, which allows for the
amplification of specific fragments from the total genomic DNA. This contrasts with earlier
approaches that often-required large amounts of DNA or protein, which often meant
killing the organism of study. PCR is now an important part of wildlife disease
management, and rapid detection of low intensities of viral, bacterial, and parasitic
infections are now possible using tests based on PCR. PCR also amplifies old and degraded
DNA, such as that found in fossils. Molecular markers, which are biological molecules that
may be used to estimate population genetic diversities, are collected in the form of
‘molecular markers,’ and PCR is used to amplify these markers.
In addition, molecular tools such as restriction fragment length polymorphism (RFLP)
analysis and single nucleotide polymorphism (SNP) genotyping are also widely used in
genetic resource conservation. These techniques allow scientists to study genetic diversity
at the molecular level, providing valuable information about population structure, gene
flow, and genetic relationships among different populations. RFLP involves the use of
restriction enzymes to cut specific sequences of DNA giving variable lengths of the strand
that can them be compared through gel electrophoresis to determine the variations or
polymorphism in the population. This is used to identify the disadvantaged variants and
conserve them.
SNP however determines the polymorphism in the population through the variation of
single nucleotides in the DNA sequence. The variations in nucleotides can either be
neutral SNP meaning it is not causing a major change in the phenotype of the organism
or it can be a functional SNP that causes a major change in the phenotype of the organism.
Molecular techniques have been used to identify migration corridors between
populations that can prevent isolation of endangered populations, detect hybrid zones
and admixed populations, quantify dispersal and gene flow, estimate current and
historical population size, assess parentage, relatedness, reproductive success, mating
systems, and social organization. Molecular ecology meets systematic conservation
planning, and it is an important tool for successful wildlife conservation.
In the effort to store and conserve the endangered species, molecular techniques like
germplasm is used. Germplasm refers to genetic resources such as seeds, tissues, and DNA
sequences that are maintained for the purpose of animal and plant breeding,
conservation efforts, agriculture, and other research uses. These resources can take the
form of seed collections stored in seed banks, trees growing in nurseries, animal breeding
lines maintained in animal breeding programs, or gene banks. Germplasm collection is
important for the maintenance of biological diversity, food security, and conservation
efforts. It ranges from collections of wild species to elite, domesticated breeding lines that
have undergone extensive human selection. Germplasm conservation is crucial for
preserving plant diversity and ensuring food security. It involves the collection, storage,
analysis, documentation, and exchange of genetic information. Germplasm can be stored
ex situ in seed banks, botanic gardens, or through cryopreservation, which is the process
of storing germplasm at very low temperatures, such as liquid nitrogen, to ensure its
preservation. In addition to traditional storage methods, genetic information is
increasingly being stored online. Germplasm conservation is instrumental in maintaining
agricultural biodiversity and has become an essential tool in genetic resource
conservation.
Tissue culture can also be used, tissue culture is a plant biotechnology technique that
involves applying in vitro (laboratory) culture procedures to maintain and multiply plant
germplasm accessions. This method enables the propagation of plant species with high
multiplication rates, allowing for conservation for short to medium terms or even long
periods. Tissue culture provides insect- and disease-free material, reduces space and labor
requirements, and takes less time to produce new plants compared to conventional
methods like seed propagation. In vitro culture stores plant genetic material in an artificial
nutrient medium, providing an alternative way to conserve vegetatively propagated plant
genetic resources (PGRs).
One of the key advantages of using molecular tools in genetic resource conservation is
their ability to provide accurate and precise data that can inform conservation decisions.
By analyzing genetic data, scientists can identify populations at risk of genetic erosion,
assess the impact of environmental changes on genetic diversity, and develop strategies
to preserve genetic resources for future generations.
Furthermore, molecular tools offer a non-invasive and cost-effective way to study genetic
diversity in wild populations. By collecting genetic samples from hair, feathers, or feces,
scientists can extract DNA and analyze genetic diversity without the need to capture or
disturb the animals. This approach allows for the monitoring of genetic diversity in
threatened species and the development of conservation plans to protect their genetic
resources.
Despite the significant advancements in molecular tools for genetic resource
conservation, there are still challenges that need to be addressed. One of the key
challenges is the lack of standardized protocols for data analysis and interpretation, which
can lead to inconsistencies in genetic data and hinder the development of effective
conservation strategies. Additionally, the high cost of some molecular tools may limit their
widespread use in conservation efforts, particularly in developing countries.
In conclusion, molecular tools play a critical role in genetic resource conservation by
providing scientists with valuable insights into genetic diversity, population structure, and
evolutionary relationships among different populations. These tools offer a more
comprehensive understanding of the genetic makeup of species and enable the
development of tailored conservation strategies to preserve genetic resources for future
generations. By harnessing the power of molecular tools, scientists can make significant
contributions to the conservation of biodiversity and the protection of valuable genetic
material for the benefit of all living organisms.

Marker Assisted Selection (MAS) in Plant and Animal Breeding

Marker-assisted selection (MAS) is a breeding technique used in agriculture to assist in
the selection of desirable traits in plants or animals. It is an indirect selection process
where a trait of interest is selected based on a marker (morphological, biochemical or
DNA/RNA variation) linked to a trait of interest (e.g. productivity, disease resistance,
abiotic stress tolerance, and quality), rather than on the trait itself.
It involves the identification and use of molecular markers, which are specific DNA
sequences associated with particular traits or genes of interest. By analyzing these
markers, breeders can more efficiently select individuals with desired characteristics, such
as resistance to diseases or improved yield. MAS can speed up the breeding process and
enhance the precision of trait selection.
Marker-assisted breeding uses DNA markers associated with desirable traits to select a
plant or animal for inclusion in a breeding program early in its development. This approach
dramatically reduces the time required to identify varieties or breeds which express the
desired trait in a breeding program. The marker may be the sequence of the gene that
determines the trait, but in most cases, it is a DNA sequence which is located very close
to the gene of interest and is therefore always inherited with the trait.
For example, using MAS to select individuals with disease resistance involves identifying
a marker allele that is linked with disease resistance rather than the level of disease
resistance. The assumption is that the marker associates at high frequency with the gene
or quantitative trait locus (QTL) of interest, due to genetic linkage (close proximity, on the
chromosome, of the marker locus and the disease resistance-determining locus). MAS can
be useful to select for traits that are difficult or expensive to measure, exhibit low
heritability and/or are expressed late in development. At certain points in the breeding
process the specimens are examined to ensure that they express the desired trait.

Marker-assisted selection (MAS) is applied in plant or animal breeding through the

following steps:
1. Determining the specific traits or characteristics you want to improve, such as disease
resistance, yield, or nutritional content.
2. Identifying molecular markers that are associated with the target traits. These markers
could be DNA sequences linked to genes controlling the desired traits.
3. Conducting genetic screening on a population of plants or animals to identify individuals
carrying the desired markers. This is typically done through DNA analysis.
4. Selection: Choose individuals that possess the target markers for further breeding. This
is more efficient than traditional methods because it allows for the selection of desirable
traits at an early stage, even before the actual expression of the trait is observable.
5. Breeding: Cross individuals with the desired markers to create the next generation. This
process helps concentrate the favorable genetic material.
6. Validation: Validate whether the selected individuals indeed exhibit the desired traits.
This can involve further testing or observation of the offspring.
7. Iterative Process: Repeat the cycle, continually refining the breeding population over
successive generations to achieve the desired level of improvement in the target traits.
Marker-assisted selection accelerates the breeding process by enabling the identification
of desirable traits at the genetic level, providing a more focused and efficient approach
compared to traditional methods.
Advantages
1. MAS accelerates the breeding process by enabling the identification of desirable traits
at the molecular level. This efficiency reduces the time required for traditional breeding
methods, allowing for faster development of new varieties.
2. MAS allows breeders to pinpoint specific genes or markers associated with desired
traits, increasing the precision and accuracy of selection. This targeted approach
minimizes the risk of introducing unintended traits during the breeding process.
3.MAS enables the identification of desirable traits at early stages, often before the
phenotypic expression is visible. This early detection helps in selecting superior individuals
without the need for time-consuming and resource-intensive field trials.
4. By reducing the reliance on extensive field trials and facilitating more accurate trait
identification, MAS can lead to cost savings in breeding programs. Resources can be
directed more efficiently towards promising candidates.
5. MAS enhances the success rate of breeding programs by providing breeders with
valuable information about the genetic makeup of individuals. This knowledge aids in
making informed decisions and increases the likelihood of developing improved varieties
with desired traits.
6.MAS is applicable across a wide range of crops and species. Its versatility makes it a
valuable tool for breeders working on diverse agricultural products, contributing to
advancements in various sectors of agriculture.
7. With MAS, breeders can customize traits based on specific needs, such as resistance to
diseases, pests, or environmental stress. This customization allows for the development
of crops that are better suited to local conditions and market demands.
Disadvantages
1. Implementing MAS can require significant initial investment in technology and
infrastructure. Access to the necessary equipment and expertise may be limited in some
regions, hindering widespread adoption.
2.The relationship between genetic markers and phenotypic traits is not always
straightforward. Complex traits influenced by multiple genes and environmental factors
may pose challenges in accurately predicting phenotype based solely on markers.
3. The use of biotechnology, including MAS, may raise ethical concerns among some
communities. Issues related to genetically modified organisms (GMOs) and their
acceptance in agriculture can lead to public skepticism and resistance.
4. Overreliance on specific markers for selection can potentially lead to reduced genetic
diversity within a population. This reduction may increase vulnerability to emerging
diseases or environmental changes.
5. The lack of standardized markers across different crops or species can complicate the
application of MAS. Compatibility issues and the need for specific markers for each
breeding program may slow down the adoption of MAS.
6. MAS requires advanced molecular biology techniques, and not all crops or livestock
species have well-established marker systems. Technical challenges in marker
development and validation can limit the widespread application of MAS.
7. The release of genetically modified organisms, which may be involved in MAS, may raise
environmental concerns and trigger regulatory challenges, affecting the acceptance and
deployment of MAS-derived varieties.
8.MAS is more effective for traits controlled by a few major genes. For complex traits
influenced by many genes, environmental factors, and interactions, the predictive power
of MAS may be limited.
It's important to note that ongoing research and technological advancements may address
some of these challenges, and the landscape of marker-assisted selection is dynamic.
Uganda has been involved in research and efforts to incorporate marker-assisted selection
(MAS) in its agricultural practices, particularly in crops such as bananas and cassava.
Bananas: Uganda is a significant producer of bananas, and researchers have explored the
use of MAS to improve banana varieties. The focus has been on developing bananas with
resistance to diseases like banana bacterial wilt and banana bunchy top virus.
Cassava: Cassava is a staple crop in Uganda, and MAS has been considered to enhance
breeding programs. The aim is to develop cassava varieties with improved resistance to
diseases, pests, and environmental stress.