STIGMA

PRINCIPLE OF SEED PROPAGATION the variously shaped apical part to which the pollen
may adhere.

STYLE
FLOWER - stalk connecting the ovary to stigma; passageway
for pollen
- organ of the plant;
- gives rise to the fruit OVARY
- Holds the eggs awaiting fertilization; becomes the
- Produced by spermatophytes or flowering fruit.
plants (seed plants).
OVULE
– “small egg” that grows into a seed after
fertilization

TYPES OF FLOWERS (PRESENCE OF

REPRODUCTIVE ORGAN)

Flowers contain

PETALS(corolla)
- Floral organs that have unique shape and colors
to attract pollinators.
RECEPTACLE
-
the
axis SEEDS
of a
basic biological unit for the reproduction of conifers
(gymnosperms) and flowering
plants(angiosperms).
▪ ripened ovule next to sexual generation for a
plant.
▪ gives rise to offspring that varies genetically from
the parent plants.
flower to which the ▪ species preserve its identity yet constantly
other parts are attached exchange genetic material within the species so
that it can evolve and so adapt to changes in the
PEDUCLE environment.

- the axis of a flower to which the The objectives of seed production can be
other parts are attached summarized as follows.
1. High Agricultural Production
2. Rapid Multiplication
3. Timely Distribution
4. Seed Quality
SEPAL (Calyx)
5. Reasonable Price
 Protect the growing bud or the flower before
it open. ADVANTAGES
▪ Seedlings are cheaper & easy to raise
Calyx and corolla are collectively called perianth ▪ Seeds can be transported to distant places
▪ Does not require high technical knowledge and
STAMEN skilled labor
Stamen is the male organ of the plant consist of; ▪ Responsible for the production of chance
1. Filament - stalk bearing a variously shaped seedlings of superior attributes
body ▪ Good opportunity to produce new hybrids or
-Produces pollen varieties
2. Anther - tip which is filled with a fine, ▪ Comparatively more hardy
yellow, dust -like substances called pollen ▪ Seeds can remain dormant if environment is not
- Support the anther conducive
PISTIL
Pistil is the female organ of a plant. made up of
enlarged ovary (with embryo sac), a columnar style,
and distal stigma (receives the pollen)
DISADVANTAGES
▪ Fruit and plantation crops from seeds take a
longer time ORTHODOX
▪ Not true to type
▪ Not uniform in their growth, yielding capacity and
quality tolerate drying to as low as 5% seed moisture
▪ Tend to grow tall under common conditions and low storage
▪ Seed propagation can’t be applied in many plants temperatures

CHARACTERISTICS OF GOOD QUALITY SEEDS RECALCITRANT

\
▪ True to its type readily killed by drying, most especially if moisture
▪ Pure, viable, vigorous and have high yielding content falls below the critical value (12- 30%)
potential
▪ Free from seed borne diseases and pest infection
▪ Clean; free from weed seeds or any inert
INTERMEDIATE
materials
▪ Whole and not broken or damaged; crushed or can be dried to levels safe for orthodox
peeled off; half-filled and half rotten seeds without their viability being
▪ Should meet the prescribed uniform size and affected but are easily injured when exposed to low
weight temperatures
▪ As fresh as possible or of the proper age
▪ Contain optimum amount of moisture (8-12%) SEED GERMINATION
▪ Have high germination percentage (more than
80%) ✓ Seed germination may be defined as the
▪ Germinate rapidly and uniformly when sown fundamental process by which different plant
species grow from a single seed into a plant.
SEED STRUCTURE ✓ This process influences both crop yield and
quality.
Fully developed seeds usually consist of; ✓ There are four environmental factors which affect
- seed coat – protects the seed
germination: water, oxygen, light, and heat.
- embryo—a tiny plant with a shoot and a root
- seed leaves (cotyledons)—that is surrounded by
There are two basic ways in which seeds
a mass of food (endosperm).
germinate.
In some plants, the seed’s endosperm
completely surrounds the embryo and
forms the storage tissue of the mature
embryo, as with onions (Allium).

How Seeds Developed

Once the flower has been fertilized, the petals

begin to fade and then fall, and the ovary begins to
swell. The stigma and stamens wither and die. The
fertilized egg cells (ovules) within the ovary each
develop a seed coat (testa) to protect their
embryos, while the ovary walls form a protective
layer (pericarp) around the seeds. Together
the seeds and pericarp form the fruit. It may be
succulent, when the middle layer of the pericarp
becomes thick and fleshy as with the rosehip, or ENVIRONMENTAL FACTORS AFFECTING SEED
dry and hard or papery. As the seeds mature, the GERMINATION
ripening fruit changes color. Fleshy fruits often
ripen from green to a bright color. 1. Water
✓ 1st step in seed germination process is the
absorption of water.
✓ Amount of available water in the germination
medium affects the
uptake of water.
✓ continuous supply of water is important to ensure
seed germination.

2. Oxygen
✓ important and essential source of energy need
for seed growth.
✓ required for the metabolism and is used as a part
of aerobic respiration until it manages to grow
green leaves of its own.
✓ Oxygen can be found in the pores of sand
particles, but if the seed is buried too deep it will be Petridish Method
deprived of this oxygen.
✓ Some seeds germinate over a wide range of Seeds are placed in absorbent
temperatures, whereas others require a narrow material in a dish. Germination
range test for a very small seeds

3. Heat/ Temperature
Germination rate is the average number of seeds
✓ Favorable temperature is another important
that germinate over the 3 and 6- day periods.
requirement for germination.
✓ It not only affects the germination percentage but Formula: Germination (%) = 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑒𝑒𝑑𝑠 𝑡ℎ𝑎𝑡
also the rate of germination 𝑔𝑒𝑟𝑚𝑖𝑛𝑎𝑡𝑒𝑑 X 100 𝑁𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑒𝑒𝑑𝑠 𝑜𝑛 𝑡ℎ𝑒 𝑡𝑟𝑎𝑦
✓ Some seeds germinate over a wide range of
temperatures, whereas others require a narrow A good seed should germinate at least 85 %
range.
4. Light or darkness
✓ act as an environmental trigger. Generally, seeds FACTORS INFLUENCING THE LIFESPAN OF
require darkness to germinate but sometimes it SEEDS
requires light. ❑ Genetic factors
❑ Initial seed Quality
❑ Seed Moisture
❑ Pre and post-harvest conditions
Seed vitality ❑ Oxygen Pressure during storage
○ one of the primary determinants of high ❑ Effect of storage conditions on the activity of
yield that directly affects the performance of organisms associated with seeds in storage
seedling emergence and plant growth. - Bacteria, Fung, Insects and Mites,
○ may be lost during storage because of Rodents and Birds
unfavorable conditions, such as high
moisture content and temperatures
SEED TREATMENT
Genotype ➢ a process of application of chemical
o A genotype is an individual's collection of ➢ protectants (with fungicidal, insecticidal,
genes. The term also can refer to the two alleles bactericidal, nematicidal or biopesticidal properties)
inherited for a particular gene.
➢ nutrients, hormones or growth regulators
o The genes partly determine the observable
characteristics of an organism (phenotype), ➢ includes control of pests when the seed is in
such as fruit and seed color, seed height, width storage and after it has been sown/planted
and length, etc.
Reasons for Seed Treatment:
Seed maturation ➢ To protect from seed borne pests and diseases.
o is a key period in a plant's life cycle allowing ➢ To protect from or repel birds and rodents.
for distribution of offspring in space and ➢ To supply plant nutrients.
time. ➢ To inoculate microorganisms.
➢ To supply growth regulators.
➢ To supply selective herbicides.
➢ To break seed dormancy.
▪ A germination test determines the ➢ To induce drought tolerance.
percentage of seeds that are alive in any seed lot. ➢ To induce higher germination percentage, early
▪ The level of germination in association with seed emergence.
vigor provides a very good estimate of the ➢ To facilitate mechanized sowing.
potentially field performance

Standard Germination Test SEED STORAGE

Identified as the conservation of seeds obtained
Ragdoll method or rolled-towel test from the harvest until they are planted for
successful crop production. ▪ The seeds are
Seeds are arranged in rows and rolled up. The required to be conserved through proper storage
rolled material is placed in a germinator. for a short or long period. ▪ During the storage of
seeds, moisture is appropriately controlled for the
protection of deterioration.

Seed box method

Seeds are sown in previously sterilized soil