Applied tree breeding initiating with phenotypic selections require a series of works such as
establishment of infrastructures concerning formation of reproduction
populations and conservation of genetic material. The main applications are selection of plus trees,
grafting, establishment of seed orchards, clonal parks and progeny trials. Applied
tree breeding activities rely on to be made genetic
tests (progeny testing) and reproduction biology research. Genetic
tests constitute the considerably important part of these research studies.
Division has six ongoing research projects concerning
progeny tests and reproduction biology.
 a-Selection
of Plus Trees: Phenotypic selection is
the initial step for the wild species to be subject to breeding works. Genetic variation
that is the source of selection is distributed within the species among and within the populations.
The aim of selecting seed stands and plus trees, is to take advantage of variance among populations and
within populations respectively. While selecting plus trees characters
to be improved are taken into consideration. The
number of plus trees selected up to now is 6920 for 11 species.
b-Grafting
Works: Vegetative production techniques
are used in order to
establish seed orchards from outstanding individuals
and to make ex situ conservation. Each individual
propagated by vegetative techniques has exactly the same genotype of the ortet.
Grafting is the main method for species that can’t be produced
thorough other vegetative propagation techniques. Scions that are taken
from superior individuals in breeding populations are grafted on suitable
root stocks that were raised in nurseries. Grafted seedlings mainly
used for establishment of seed orchards and clone banks.
 c-Seed
Orchards:
Improved
seed material is produced mainly at seed orchards. Because seed orchards
are established on more suitable areas and is applied more intensive cultural
treatments, seed production is more abundant and more frequent compared to seed stands. Additionally, genetic gain is higher
due to existing the possibility of exchanging genes among the selected individuals.
Seed orchards may be established in two ways according to breeding strategies
and characteristics of the species.
* Clonal Seed Orchards: These orchards are established through grafted seedlings. The number of seed orchards established until now is 166
for 11 species covering 1155 hectares. * Seedling Seed Orchards: These
orchards are established by the seedlings that are raised thorough
seeds from selected individuals of the species that
form seed in an early age. The number of established seedling seed orchards until now is
35 for 19 species covering 184 hectares.
d-Clone
Banks: Clone banks are basic units for ex situ gene conservation
of individuals in breeding population as well as facilitates control crossing due to plantation of the same clones propogated thorough grafting or other vegetative methods from selected individuals side by side.
The number of clone banks established
until now for 5 species is 10 and cover an area of 20 hectares.
 e-Progeny
Trials: Most of tree breeding programs require
ranking of each individual genetically in breeding populations. The need of
ranking breeding values mainly is required for the species that can't be propogated by
vegetative techniques. Progeny trials are
the unique genetic tests for determining breeding values of trees. Additionally,
the aim of this test is to estimate genetic gain obtained from
selection, to estimate genetic parameters and to provide demonstration.
Although it is possible to perform progeny trials as open pollinated progeny trials and control pollinated progeny trials,
in "National Tree Breeding and Seed Production Programme For Turkey 1994-2003" was suggested open pollinated progeny trials.
The
most comprehensive progeny trial project of Turkey with native forest
tree species has been initiated. Turkish Red Pine (Pinus brutia Ten.) was given priority for progeny trials
according to this Programme.
|