Post on 10-Feb-2016
description
SEXUAL PLANT PROPAGATION
DEFINITION Propagation-to reproduce or increase in
number
TYPES OF PROPAGATION: Sexual
Uses seedsRequires the union of pollen (male sex
cells) and egg (female sex cell) in the ovary
AsexualProduces exact duplicates of the plantUses part of the plant, such as leaf, stem,
or rootAsexual propagation is possible because
each individual cell of a plant has all characteristics of the entire plant and can re-grow missing parts
PROPAGATION FROM SEEDS: Benefits
Quick Inexpensive Easy
Special requirements Scarification-weakening of the hard seed coat
Ex: sandpaper, scratching or acid bath Cold shock-moist, cold rest period for 8 weeks
or longer Light Darkness
**Therefore, always follow the planting instructions**
COMPOSITION OF SEEDS: Seed coat
Outside covering that protects the embryonic plant
Makes transportation and storage possible Endosperm
Stored plant foodThe first start of growth in a seed
Embryo (embryonic plant)New plant that is developed as a result of
fertilizationExtends root and seed leaves to form a
new plant
WHAT’S NEEDED FOR GERMINATION? Temperature Moisture Air Light or absence of it
PROCESS OF GERMINATION Seed absorbs water Seeds proteins activated Radicle (root) emerges Plumule or embryonic shoot emerges Leaves form and food production begins
MONOCOT SEEDS Seed coat-protection Endosperm-a source of energy Embryo-miniature plant that has: Epicotyle-shoot above cotyledon Hypocotyl-part of stem below the cotyledon Radicle-primary root, supports seedling
MONOCOT GERMINATION Seed swells Radicle grows down First internode and epicotyl grows upward New leaves form and food production starts New root system develops Temporary root system ceases to function
and dies
DICOT SEEDS Seed coat-protection Embryo-miniature plant 2 cotyledones-seed leaves Epicotyl-true leaves Hypocotyl-first stem, pulls seed upward Radicle-forms roots
DICOT GERMINATION Seed swells Radicle grows down Hypocotyl forms arch that breaks soil surface Hypocotyl reaches light and straightens up Cotyledons turn green and make food As new leaves develop, cotyledons dry up
and fall off
SEEDING
SELECTION OF SEEDS: Identify seeds grown locally Check germination ability Purchase from a reliable dealer Chose hybrid varieties for greater vigor,
uniformity, and flowering ability Select uniform heavyweight or primed seeds
IMPROVING GERMINATION OF SEEDS: Sorting Seed quality Weight
Heavier seeds tend to grow faster and produce larger plants
Primed or enhanced Soaking in salt solutions of KCl or ethyl
alcohol Causes growth hormones to become active More uniform, germinate sooner
GERMINATION MEDIUM Soil characteristics
FirmPorousUniform in textureSterileFree of weeds, insects, and disease
organisms
SOIL COMPOSITION
Loam composed of: 45 % mineral matter 5 % organic matter 25 % air 25 % water
What is loam? Equal parts of sand, silt, and clay
GERMINATION MEDIA: Peat moss
Partially decomposed vegetation that has been preserved under water
Collected from marshes, bogs or swampsHas high capacity for holding water
Sphagnum mossDehydrated remains of acid bog plantsSterile and lightweight, controls disease
and has excellent water-holding capacity Perlite
Volcanic origin that expands when heated Improves aeration and drainage of media
GERMINATION MEDIA: Vermiculite
Neutral pH High water-holding capacity
Jiffy mix Composed of sphagnum moss, peat, fine grade
vermiculite, and nutrients To make your own media:
Good grade, sterilized topsoil Proper drainage from sand or perlite Peat, moss or vermiculite to add water-holding
capacity 1/3 soil, 1/3 drainage material, 1/3 water-
holding material Sterilized or pasteurized by heating at 180°F
for one-half hour