Assessment of genetic diversity in Picea orientalis (L.) Link. in genetic resources by microsatellites


Tezin Türü: Doktora

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

Tezin Onay Tarihi: 2015

Öğrenci: ASLI ÖZDİLEK

Danışman: ZEKİ KAYA

Özet:

Picea comprises about 40 species in the world. One of these species, oriental spruce (Picea orientalis (L.) Link.) is naturally distributed in northeastern Turkey, mostly in Artvin Province and in a part of Georgia close to the coast of the Black Sea region. The limited distribution of species and increased anthropogenic threats to its genetic resources signify the importance of studying genetic diversity of the species to have better conservation and management programs. Here, we report the first high throughput genetic diversity analysis of P.orientalis using microsatellite markers. In detail, 277 individuals of eight different populations were sampled throughout the geographic range and screened with 15 SSRs (Simple Sequence Repeats) loci to assess the genetic diversity patterns and structure of the species. Oriental spruce populations were evaluated according to the parameters of the basic genetic diversity and the structure. These populations were also grouped and evaluated according to the types of tissues used in the sampling. According to the descriptive statistic results obtained from the present study in terms of microsatellite markers, the number of polymorphic loci was found as 14 and the percentage of polymorphic loci (PI) was determined as 93%. The highest number of alleles and the highest observed heterozygosity were detected in SS17 locus as 25 and 0.92, respectively. Moreover, the highest effective number of alleles was found in SS15 locus (9.34). Among the populations of oriental spruce, the highest genetic diversity (Ho=0.580.07) was detected in C-Trabzon and the highest number of private alleles (13) was found in SE-Artvin population (Southeastern Artvin). Furthermore, SE-Artvin was genetically the most distant population based on the factorial correspondence analysis (FCA). On the other hand, the lowest genetic diversity (Ho=0.450.04) was estimated in Giresun and the lowest private alleles (2) were observed in C-Trabzon. The results of genetic structure analysis revealed that the populations of oriental spruce were grouped into four main clusters (K). These were Trabzon (Giresun, W-Trabzon, CTrabzon, E-Trabzon), Artvin (S-Artvin, N-Artvin), C-Artvin and SE-Artvin. Considering all the data related to this issue, our results comply with a general population genetic pattern where geographically close populations exhibited higher genetic similarity than geographically distant populations. However, comparing seed and needle samples in respect to geographical location, there was no remarkable differences or similarity in genetic diversity parameters. In conclusion, this study provided experimental evidence revealing the genetic diversity parameters evaluated by means of SSR markers and structure of oriental spruce populations for the first time. Specifically, SE-Artvin and C-Trabzon populations are recommended to be included in future conservation programs dealing with oriental spruce.