Transcript Metoda Pemuliaan Tanaman Secara Khusus

Special Methods in Plant
Breeding
Taryono
Faculty of Agriculture
Gadjah Mada University
Plant evolution vs breeding?
Plant breeding:
 selection is predominantly artificial
 natural combined
 objectives and strategies are defined on the
basis more or less secure scientific
knowledge
Plant Breeding
 An election made by man of the best plants
within a variable population as a potential
cultivar
A selection made possible by the existence
of variability
Plant evolution directed by man
Applied genetics
Applied evolution
Objective
 economically and biologically reasonable
 Increase yield by improvement of the potential
productivity followed by the successful expression
of that potential
 Improve quality
 Make crops more amenable to mechanical handle
 Adapt crops to new microclimate area
Breeding work step
What parent to include and why
What pattern of crossing and passage
through the generation to adopt (mating and
propagation systems)
What methods of selection to use
How to decide upon the ultimate release or
discard of the product
Product of Breeding Work
Variety
A plant differing from other member of the species to which
it belongs by the possession of some hereditary traits
 Clone variety
It is maintained by vegetative propagation
 Line Variety (Open pollinated variety)
It is maintained by self fertilization
 Pan-mitic variety
It is propagated by cross-fertilization
 Hybrid variety
It is produced by directed crosses
Open pollinated variety
1. Once new seeds are developed, they can be
freely propagated by farmers or other seed
suppliers
2. Later generations maintain their productivity
Hybrid Variety
1. It is produced by crosses of different varieties
even different species and done in very
controlled conditions
2. It shows hybrid vigor (heterosis)
3. Later generations of hybrid seeds are much less
productive
4. Farmer must purchase seeds every plant
seasons
Heterosis
The increased vigor of growth, survival, and fertility of
hybrids as composed with two homozygotes
It is always associated with the increased heterozygosity
1. F1 yielding more than the mean of the parents (midparent heterosis)
2. F1 yielding more than the best yielding parents
(better parent heterosis = heterobeltiosis)
3. F1 yielding more than the best yielding variety
(Standard heterosis)
Why private seed industry
interested in hybrid seeds?
1. A firm considering the possibility to develop a new
open pollinated seed variety seeds needs to include
the development costs into the selling price of the
seeds
2. But a competing seed supplier can simply by a small
sample of seeds from the innovator and sell the
seeds that cover the propagation costs only, not the
development cost
3. Knowing that potential competitors will have this
cost advantage, no individual firm is interested to
develop new open pollinated varieties
Course Contain
 Reproduction system
 Heterosis
 Quantitative genetic of heterosis
 Genetic diversity and heterosis
 Hybridization
 Male sterile
 Future out look
Grading system
Grade : 0 – 100
 B–D
 A > 80
→ 45 – 80 (Normal distribution)
 E < 45
Grade composition
Home work
Mid-term
Final Exam
:
:
:
30
30
40