Study On Intraspecific Differentiation Of Picea Mongolica

Picea mongolica is distributed exclusively in the eastern edge of the fixed sand dunes in Hunshandake Sandy Land, China. It is also a key species in one of the largest afforestation projects in the world, the construction of the "Three-North"(North-West, North and North-East China) shelterbelt. Each P. mongolica tree possesses only one cone colour (purple, red or green), which remains unchanged from fructification to cone dropping and it is always the same as the tree ages. For the convenient, three different cone types, that is, P. mongolica f. purpurea (purple), P. mongolica f. rubra (red), and P. mongolica f. viridis (green) are shorted as purple cone type, red cone type and green cone type.The researches of intraspecific differentiation of P. mongolica focus on the morphology, biochemical and physiological indices etc., and the differentiation was found in these studies.Due to lacking of research of genetic markers, this study focuses on the microsatellites to study the intraspecific differentiation of P. mongolica.Obtaining the primers of microsatellites is the key for this study. However, high conservation in the flanking sequence of microsatellites'primers guides us to quote7pairs of flanking sequence from the database of Picea abies and Picea glauca as genetic markers in PCR amplification and genotyping. GeneMapper software is used for the analysis of genotyping and statistical analysis. Genepop and Structure software are for calculating the parameters and cluster analysis. The result showed the differentiation exists in these three different cone types.The result, that derived from7pairs of microsatellites (data set A), illustrates the Fst in the pair green cone type and red cone type is the most great, and the information of differentiation in the genetic level degree reach to2.83%. Gene flow, in the purple cone type and red cone type hit the top in the three pairs, demonstrating gene flow in this pair seem to be frequent. In addition, results, from gene flow and Fst analysis, keep pace with each other,showing the degree of differentiation, in the pair of purple cone type and red cone type, is the lowest, however, the opposite result in the pair of green cone type and red cone type. Cluster analysis give the corresponding information, that the degree of differentiation of three pair, in genetic level, is not great. However, the P-value gives the opposite points, and the pair of the green gene type and red cone type keeps the greatest differentiation in three pairs.3of7microsatellite data (data set B), fitting Hardy-Weinberg Law, to anolog Hardy-Weinberg Law, indicates the same result, that is, the pair of the green gene type and red cone type had the greatest differentiation. However, the result, from3microsatellites, illustrates the degree of differentiation in the pair of the green gene type and red cone type, is greater than that from7microsatellites. The data of gene flow also released the same information. However, P-value Test for genetype differentiation analysis still supports three pair has the differentiation.P. mongolica mainly distributed in one area and the mount of individual is small. Meanwhile, the great natural selection renders the Hardy-Wenberg Law of P. mongolica unbalance.Refer to previous researches, this study analyzed the causes of intraspecific differentiation, that is, unbalanced moisture distribution, ground water change, seed rain etc., make P. mongolica have the differentiation in one species.