Abstract: To optimize the inter simple sequence repeat (ISSR) reaction condition for Magnolia officinalis genomic DNA, the concentrations of Mg²⁺, Taq polymerase, primers, deoxyribonucleot-ide triphosphate (dNTP), and template DNA were studied with an orthogonal experimental design, and the optimal anneal temperature of different primers and cycles were determined through gradient PCR. The optimal PCR system for ISSR analysis was 1.5 mmol MgCl₂·L^-1, 03 μmol primer·L^-1 0.04 U Taq polymerase·μl^-1, 0.2 mmol dNTP·L^-1, 4 ng DNA template·μl^-1, and 1×Buffer in 25 μl reaction solution, and the augmentation procedre was predenaturation at 94 ℃ for 5 min, denaturation at 94 ℃ for 30 s, annealing at 50 ℃-60 ℃ for 45 s, extension at 72 ℃ for 90 s, reaction with 40 cycles, and extension at 72 ℃ for 8 min. Twentyone ISSR primers were screened by using the optimal reaction system, and the genetic diversity was analyzed with some primers.

Key words: Caloric value, Ash content, Monthly changes, Palmae species