Study On Genetic Structure In Different Populations Of Pinus Koraiensis By SRAP

In this paper the genetic diversity and differentiation of 24 populations were studied by the newly developed method of Sequence-Related Amplified Polymorphism (SRAP) marker. The SRAP-PCR reaction system is originated, relativity between genetic structure and growth character were studied. The results show as follows:(1) Genomic DNA was extracted from leaves of Korean pine by the method of modified CTAB. Although at the first suspension time we didn't get genomic DNA, at the second suspension time we obtained high quality and purity genomic DNA which can meet the request of PCR reaction.(2) The optimal SRAP-PCR reaction system for Korean pine is instituted in the study. We optimized five main factors influencing the amplification of PCR, and got the suitable reaction system of 20μL:1×Buffer, 2.5mmol/L of Mg²⁺, 0.15 mmol/L of dNTPs, 0.15μmol/L of each primer, 40～100ng of DNA template, 1.5unit of Taq DNA polymerase. A thermal cycle was implemented with the following program: the first five cycles were run at 94℃(1 min), 35℃(1 min), and 72℃(30s) for denaturing, annealing, and extension, respectively. Then, the annealing temperature was raised to 50℃for another 30 cycles. After the completion of the 35 cycles, the reaction mixture was incubated for 7 min at 72℃.(3) 9 SRAP primers were selected for PCR and produced 249 band loci, of which 143 (P=55.42%) were polymorphic, the average number of bands per primer was 15.9. Compared with species already issued, the genetic diversity of Korean pine is a higher level.(4) It is basically identical that genetic diversity level in 24 populations by effective number of allele (Ae), Nei Index (H) and Shannon Index of diversity (I). The highest diversity was found in Dahailin population. The lowest diversity was found in Bajiazi population. Furthermore, The significance difference does not exist in genetic diversity of 24 populations by analysis variance.(5) The percentage of genetic diversity within Korean pine population is 92.35% in the total value, The percentage of genetic diversity be among the Korean pine populations is only 7.65%, that means the genetic variation is mainly occurred inner Korean pine population. The mean of gene flow (Nm) was 2.9069, which showed relatively steady gene flow among populations, reduce genetic variance.(6) The significance difference does not exist in tree height and breast diameter of 24 populations by analysis variance, It is identical that genetic diversity level and growth properties.