Tree seed technology and improvement.ppt

• A seed is defined as a matured and fertilized ovule containing an
'embryo,' which is a living organism enclosed in supporting or food
storage tissues, protected by the seed coat (consisting of testa and
tegmen).
• In agricultural terms, a seed is defined as the propagating material
or a unit/tool for initiating a new generation of plants.
• As per Seed Act, 1966 “seed” means any of the following classes of
seeds used for sowing or planting
(i) seeds of food crops including edible oil seeds and seeds of fruits and
vegetables;
(ii) cotton seeds;
(iii) seeds of cattle fodder; and includes seedlings, tubers, bulbs,
rhizomes, roots, cuttings, all types of grafts and other vegetatively
propagated material of food crops or cattle fodder.
Definitions of Seed

A typical seed includes three basic parts:
(1) an embryo
(2) a reservoir of nutrients for the embryo either endosperm or
cotyledon
(3) a seed coat
Parts of Seed

 The embryo is an immature plant
from which a new plant will
grow under proper conditions.
 The embryo has one cotyledon or
seed leaf in monocot, two
cotyledons in almost all dicot and
two or more in gymnosperms.
 The radicle is the embryonic
root.
 The plumule is the embryonic
shoot.
 The embryonic stem above the
point of attachment of the
cotyledon is the epicotyl.
 The embryonic stem below the
point of attachment of the
cotyledon is the hypocotyl.
Embryo

 The seed coat develops from the integument tissue (Testa and
Tegmen) surrounding the ovule
 In mature seeds, the seed coat varies from a paper thin layer
(e.g., peanut) to a more substantial, thick, and hard structure
(e.g., honey locust and coconut)
 The primary functions of the seed coat include protecting the
embryo from mechanical injury and preventing desiccation
(drying out)
 The presence of a scar on the seed coat is known as hilum
 Micropyle is a small hole present at one end of hilum in the
seed coat.
Seed Coat

Fertilization Process
• The pollen grain germinates after the carpel is pollinated.
• From the germinated pollen grain, a pollen tube emerges
and grows.
• It travels and grows and moves towards the ovary by
creating a path through the female tissue.
• Two types of nucleus, the vegetative tube and generative
nuclei of the pollen grain pass into the pollen tube.
• Stigma secretes a sugary substance that stimulates the
growth of the pollen tube.
• The pollen contains the vegetative and the generative
nucleus and the cell ruptures the stigma and passes
through the style.
• The pollen grains attaches itself to the stigma of the
female reproductive structure, the pollen tube grows and
enters the ovule making a tiny pore called a micropyle.

• The pollen tube then breaks into the ovule through
the micropyle and then the micropyle bursts into the
embryo sac.
• In the embryo sac, on the male nucleus fuses with
the nucleus of the egg and forms a diploid zygote.
This process is known as true fertilization or
syngamy.
• The other male gamete or nucleus enters further
into the embryo sac and it fuses with secondary
nucleus. This gives rise to a triploid nucleus called
the primary endosperm nucleus. This process of
nuclear fission, where there is formation of primary
endosperm nucleus is called triple fission.
• After the process of fertilization the ovary swells up
and develops into a fruit.

1. Monocot seed: the seeds which contain single cotyledon are called
monocot seeds. The scutellum in case of cereal crop acts as cotyledon.
E.g. wheat, maize etc.
2. Dicot seed: The seeds which possess two cotyledons are called as dicot
seeds. The cotyledon act as storage tissue. E.g. Red gram, soybean etc.
Classification Based on Structure and Development
Classification of seed

1. Albuminous seed: Seeds which contain
endosperm at maturity. E.g. wheat, rice, maize etc.
2. Exalbuminous seed: Those seeds which do not
contain endosperm at maturity. E.g. gram, pea,
bean, sunflower etc.
Classification Based on Presence or Absence of Endosperm

1. Orthodox seed
– The seeds which retain viability longer.
– They can be successfully dried to moisture contents as low as 4 to 8%
without injury and are able to tolerate freezing temperatures.
– At physiological maturity they contain moisture content of 30 – 50%.
E.g. wheat, rice, maize etc.
Recalcitrant seed
– Seeds which show very drastic loss in viability when dried to moisture
content below 12 to 13% and are unable to tolerate freezing.
– At physiological maturity they contain more moisture content (50 to
70%) than orthodox seeds. E.g. seeds of woody sp. like mango,
coconut potato tuber, zinger rhizome etc.
Intermediate seeds
– A third category intermediate between orthodox and recalcitrant
categories has been identified called intermediate seeds. e.g. Coffea
arabica, Azadirachta indica
Classification Based on Viability Reference to Moisture

1. High yielding variety seed: The seeds which are
developed through conventional and modern
breeding tools accompanied with systematic
selection processes and they will not quickly
degenerate in production cycle.
2. Hybrid seed: The seeds are produced through
hybridization (crossing of male and female parent),
they will quickly degenerate in production cycle.
E.g. Varalaxmi (Cotton), CSH 1 (Sorghum) KRH2
(Rice) etc.
Classification Based on Improvement

1. Microbiotic seed: The seeds which maintain their
viability upto three year viz., oxalis seeds.
2. Mesobiotic seed: These seeds maintain their
viability for 3-5 years e.g. cereal seeds.
3. Macrobiotic seed: The seed remain viable for
more than 15 years and sometimes 50-100 years
e.g. lotus seeds, lupines etc.
Classification Based on Longevity Reference to Storage Life

1. Nucleus seed:
2. Breeder seed:
3. Foundation seed:
4. Certified seed:
Based on Seed Multiplication Chain or Certification

Need of Forestry Seed Science in India
• The productivity of forests in India is low as compared to world average and forest
cover.
• Hence to improve the existing stock in terms of yield, quality, disease resistant and
desired traits, seed technology can play a major role in providing quality genetic
material.
• Large scale plantation and afforestation of waste lands with economically viable for
different ecosystems to achieve the target of forest cover as per the National Forest
Policy demands mass production of quality planting material including seeds with
desired traits.
• To overcome the problem of hunger with the growing population and
• to solve environmental problems involving micro-organisms for restoration and
conservation of plant biodiversity through biotechnological and molecular markers
would be needed.
• Forest seed science can be instrumental in producing seed gene banks, tissue culture
gene banks, pollen and spore banks.
• Introduction of quality seeds is needed for improvement of range productivity and
fodder quality for live stock to sustain rural household economy

Importance of Forestry Tree Seed: Global Perspective
• Good forestry projects start with good seeds. Lacking good genetic material to start
with, investments in other treatments will have little effect.
• In forestry as well as in agriculture, time and effort invested in procuring better
quality seeds will pay back in higher rates of survival, higher yields, and better
quality of wood and other products (Friday, 2000).
• Growers in many regions have been selecting varieties that grow faster are more
resistant to disease, and have better wood qualities.
• For example, trials in Hawaii comparing sources of Eucalyptus grandis found twice
the diameter growth rate between the worst and the best seed lots (Skolmen, 1986).
• Afforestation is no longer a matter for forest departments alone.
• The increase in population has led to change character of forest planting in
accordance with the broader spectrum of demand.

• But with shrinking forest areas and reduced land holdings
community forestry or social forestry with components of
agroforestry, shelterbelt plantation, village woodlots etc. now
makes up a major share of the total planting activities.
• Hence to full fill these needs and demands at household, village
and community level, it is important to have good quality of
seeds for land rehabilitation.
• The problems of seed destruction is increasing due to our
increasing resilience on seed sources for the production of
seedlings or for trees of known genetic characteristics in
reforestation and reclamation programmes.

• The National Forest Commission, 2006 recommends that in
order to meet the growing needs of the nation ,stress should
be laid on establishing high yielding plantations and
agroforestry based on improved planting stock.
• Tree improvement has the potential to increase productivity
immensely through use of genetically improved and certified
forest reproductive material.
• The need for better supplies of tree seeds is expected to
greatly increase, thus creating the demand for increased
research efforts.

Characteristics of good seeds
• — must be well ripened, healthy and true to type,
• — must be pure and free from inert materials
and weed seeds,
• — must be viable and have good germination
capacity,
• — must be uniform in its texture, structure and
look, and
• — must not be damaged, broken and affected by
pests and diseases.

Seed development
Development of the fertilized ovule into the mature seed involves several
different parts.
• The integuments of the ovule become the seedcoat of the mature seed.
This sometimes consists of two distinct coverings, a typically firm outer
seedcoat, the testa, and a generally thin, membranous inner coat, the
tegmen. The testa protects the seed contents from drying out, mechanical
injury, or attacks by fungi, bacteria and insects, until it is split at
germination
• The nucellus may persist in some genera as a thin layer - the perisperm -
lying inside the seedcoat and supplying food reserves to the embryo.
• The endosperm commonly grows more rapidly than the embryo during
the period immediately after fertilization. It accumulates reserves of food
and its fullest development is rich in carbohydrates, fats, proteins and
growth hormones
• The embryo occupies the central part of the seed. Its degree of
development at the time the seed ripe varies greatly according to species.
In some it is possible to distinguish all parts of the rudimentary plant - the
radicle which at germination will give rise to the primary root, the seed
leaves or cotyledons, the plumule from which will develop the primary
shoot, and the hypocotyl which connects the cotyledons with the radicle.

Fruit Development/ classification
• Development of the fertilized seed is normally accompanied by
development of the fruit. In the simplest case the ovary wall becomes
thickened to form the pericarp. This may be:
• Dehiscent, splitting open when ripe to release the enclosed seeds;
• examples are the capsule (e.g. Eucalyptus), a multilocular fruit derived
from a syncarpous ovary, and the leguminous pod (e.g. Cassia), which is
derived from a single carpel and spilts along two sutures.
• Indehiscent or dry, closely fused with the seed; examples are the achene,
a small hard one-seeded fruit with membranous pericarp,
• the samara, similar to the achene but with pericarp extended to form a
wing (e.g. Ulmus)
• and the nut, a rather large one-seeded fruit with woody or leathery
pericarp (e.g. Quercus).
• Indehiscent and fleshy, often distinguished by colour, smell and
taste to
attract fruit-eating birds and animals. Two types are distinguished.
• The berry has an outer skin and inner fleshy mass, containing seeds that
have a hardened seedcoat (e.g. Diospyros, Pouteria).
• The drupe has the inner layer of the pericarp hardened to protect the
seeds (e.g. Prunus, Gmelina, Azadirachta, Mangifera);

• Cowan (1973) identified seed technology as “that discipline of
study having to do with seed production, maintenance, quality
and preservation”.
• Feistritzer (1975) defined seed technology as the methods
through which the genetic and physical characteristics of seeds
could be improved. It involves such activities as variety
development, evaluation and release, seed production,
processing, storage and certification.
• In its broadest sense,” seed technology includes the
development of superior crop plant varieties, their evaluation
and release, seed production, seed processing, seed storage,
seed testing, seed certification, seed quality control, seed
marketing and distribution and research on seed physiology,
seed production and seed handling based upon modern
botanical and agricultural sciences”.
Seed Technology

1. It is the result of well planned seed
programme.
2. It is the result of sound scientific knowledge,
organized effort, investment on processing,
storage and marketing facilities.
3. The pedigree of the seed is ensured. It can be
related to the initial breeders seed.
4. During production, effort is made to rogue out
off-types, diseased plants, objectionable
weeds and other crop plants at appropriate
stages of crop growth which ensures
satisfactory seed purity and health.
5. The seed is scientifically processed, treated
and packed and labeled with proper lot
identity.
6. The seed quality is usually supervised by an
agency not related with production (seed
certification agency).
7. The seed is tested for planting quality namely,
germination, purity, admixture of weed seeds
and other crop seeds, seed health and seed
moisture content.
1. It is the part of commercial produce
saved for sowing or planting purposes.
2. No such knowledge or effort is required.
3. Its varietal purity is unknown.
4. No such effort is made. Hence, the rogue
out offtypes, diseased plants, purity and
health status may be inferior.
5. The grain used as seed may be manually
cleaned. In some cases, prior to sowing
it may also be treated. This is not labeled
6. There is no such quality control.
7. Routine seed testing is not done.
(Scientifically produced) Seed Grain (used as seed)

1. Rapid multiplication: Increase in agricultural production through
quickest possible spread of new varieties developed by the plant
breeders. The time taken to make available the desired quantities of
seeds of improved varieties to farmers should be considered as a
measure of efficiency and adequacy in the development of seed
technology in the country.
2. Increase in production: To increase agricultural production by supply
of quality seed
3. Timely supply: The improved seeds of new varieties must be made
available well in time, so that the planting schedule of farmer is not
disturbed and they are able to use good seed for planting purposes.
4. Assured high quality of seeds: To provide the seeds of high yielding
varieties with good vigor and viability
5. Reasonable price: The cost of high quality seed should be within
reach of the average farmer.
Major Objectives/Goals of Seed Technology

1) Genetics and Plant Breeding : The Plant Breeders and Geneticists develop new
crop varieties which are high yielding and superior in resistance to diseases and
pests as compared to existing ones.
2) Agronomy : The agronomist provide suitable package of practices for growing,
harvesting and handling of seed crops in order to obtain maximum seed yields
and best possible seed quality.
3) Horticulture : The horticulturist provide the suitable package of practices for
growing, harvesting and handling vegetable, flower and other horticultural crops
to ensure maximum seed yields and best possible seed quality.
4) Plant Pathology : The role of plant pathologist in seed production is to produce
and distribute disease free seed and hence they provide package in regard to
seed treatment and plant protection measures, to be adopted in order to produce
disease free seeds.
5) Entomology : The entomologist provide the package with regard to pest control
during seed production and seed storage to ensure good seed quality and
minimum losses due to storage.
Relationship of Seed Technology with other Sciences

6) Plant Physiology : The physiologist help in understating various planting seed
quality problems, seed development and maturation, and seed storage problem and
their possible solutions. They are associated with the development of techniques
for seed germination, seed vigour, seed viability testing.
7) Agricultural Economics : They provide necessary guidance in relation to seed
marketing problems and helps in devising suitable marketing and distribution
system. They are also concerned with the management aspects and in the
determination of cost/benefit ratio, seed price fixation etc.
8) Agricultural engineering : The agriculture engineers are associated with the
development of suitable seed planting, harvesting machinery for seed crops and
also the seed drying, seed processing machinery, seed handling and seed testing
equipments.
9) Agricultural extension : The extension agencies are involved in popularizing the
use of high quality seeds of high yielding varieties amongst the farming
community and also gave feedback to the researcher for the problems of farmers.
Relationship of Seed Technology with other Sciences

1. Dependency on Farm Saved Seed: A significant challenge in seed
technology is the prevalent reliance on farm saved seed in India, where 65%
of farmers still use their own saved seed or distributed seed. This dependency
poses obstacles in ensuring the consistent availability of quality seeds to
enhance productivity.
2. Timing and Accessibility of Quality Seeds: While there is recognition of the
importance of quality seeds for increased productivity, a major challenge lies
in making these seeds available at the right time and ensuring accessibility to
farmers. The focus should shift towards timely distribution to address this
challenge.
3. Skewed Seed Replacement Rate (SRR): Achieving a balanced Seed
Replacement Rate (SRR) is a pressing challenge. The percentage of area
sown with certified/quality seeds, as opposed to farm saved seeds, needs
improvement. Despite recent progress, there is still a considerable gap in
achieving a 100% SRR, hindering the potential for a quality seed driven
growth in the agriculture sector.
Challenges for Seed Technology

4. Market Dominance by Multinational Corporations: The
concentration of the seed market in the hands of a few multinational
corporations is a challenge that affects seed diversity. The
oligopolistic market structure limits the focus on profitable
proprietary crops, potentially excluding diverse and locally adapted
varieties. This dominance may compromise farmers' rights and reduce
genetic resources.
5. Implications of Hybrid Seeds: The adoption of hybrid seeds
presents challenges such as increased costs of seeds for small farmers,
and the uncertainty of production outcomes.
Seed technologists need to address these consequences and find ways to
balance traditional and modern seed systems, taking into account
local community based seed systems and landraces.
Challenges for Seed Technology

1. Higher Yield: Seed technology boosts crop yields through advanced
breeding and genetic engineering, addressing global food demand
2. Lower Cost: Seed technology lowers production costs by
developing genetically modified crops that require fewer pesticides
and herbicides
3. More Income: Improved seed varieties lead to higher yields,
directly increases farmer’s income which are crucial for
smallholders and rural economic development.
4. Reliability in Farmers: Seed technology provides farmers with
resilient crop varieties, ensuring reliability in unpredictable
environmental conditions.
5. Correct Information: Accurate information on seed packets
empowers farmers with essential details for optimal crop
management, preventing issues and promoting successful
cultivation.
Importance of Seed Technology

Q 1. A seed contains,
A. seed coat,
B. embryo ,
C. stored food,
D. all of the above

Q2.- Basic difference between seed and grain is,
genetic purity.
• A-True
• B- False

Q3. seeds are mature
A. ovary,
B. ovule,
C. integument,
D. cutellum

Conclusion
• When you hold a viable seed in your hand, no matter
how small it is, you are holding a future plant!
Continuous advancements in seed sciences and
technologies ensure seeds are developed, processed, and
maintained with high quality.
Seed security is food security

Tree seed technology and improvement.ppt

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