Pinus nigra subspecies pallasiana varyetlerinin, doğal populasyonlarının (tohum meşcereleri), tohum bahçelerinin ve plantasyonlarının genetik karakterizasyonu


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye

Tezin Onay Tarihi: 2005

Tezin Dili: İngilizce

Öğrenci: Burcu Çengel (Nazlıer)

Danışman: ZEKİ KAYA

Özet:

Pinus nigra subsp. pallasiana is one of the most widespread and economically important forest tree species in Turkey. Primary objective of the present study was to to reveal the effects of forestry practices by determining genetic diversity of natural and managed seed sources by means of RAPD markers. Secondly, two varieties were also investigated to reveal their pattern of genetic variation. Seed stands, seed orchards and plantations were screened against 11 RAPD primers and generated 152 polymorphic DNA loci. Two varieties were compared with a reference seed source and 4 natural seed sources. Seven primers generated 66 polymorphic DNA loci. An overall average for effective number of alleles was 1.68±0.030; observed heterozygosity was 0.49±0.024; expected heterozygosity was 0.38±0.014 and proportion of polymorphic loci was 93% for all seed sources considered. Results revealed that there was no considerable variation between seed source categories but some degree of variation was observed within seed orchards and plantations. Mean FST value estimated for the natural populations revealed that 94% of the total genetic variation was within populations. Nei̕s genetic distance values were also estimated for seed source categories (0.03-0.14). Nevertheless, varieties̕ genetic distance values were considerably higher than other natural seed sources (0.07-0.19). Their dendrogram also claimed that two varieties are genetically different from natural populations. The extent of genetic diversity explored by RAPD markers revealed that forestry practices caused no major changes in the managed populations with respect to natural populations. Moreover, further study is needed to illustrate genetic divergence of varieties.