TREE BREEDING RESEARCH DIVISION


       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.
 

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  Conception & Graphic:© Fikri Taşçı &Turgay Ezen 2000   ANKARA
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