| Cunninghamia Lanceolata, a kind of arbors in Taxodiaceae and a precious plant of quaternary ice age, is one of the main species for afforestation in southern China. Distributed in sixteen provinces and regions in south China, distribution area of C. lanceolata spans ten latitudes from north to south and15longitudes from east to west. The landscape of this area mainly contains mountains and hills, southeast of Guizhou province, southwest of Hunan province, north of Guangxi province, north of Guangdong province, south of Jiangxi province, north of Fujian province and south of Zhejiang province are the major C. lanceolata production areas in our country. According to the research of the national geographical provenance cooperation of C. lanceolata, distribution areas are divided into Qinba mountain area, Tongbai rocks of the Dabie mountain area, mountain area surrounding basin of Sichuan, Tianmu mountain of Huangshan. Yalong river and Anning valley mountain area, the Guizhou mountain area, hilly area of Hunan, Hubei and Jiangxi, Nanling mountain area, Fujian YueGui Yunnan, southern hilly area of Fujian, Guangdong, Guangxi, Yunan, which contains nine provenance areas. This paper uses ISSR molecular markers to analyze genetic diversity of C. lanceolata provenance in all distribution areas, in order to fully reveal distribution pattern of the genetic diversity of C. lanceolata provenance, discusses the relationship of C. lanceolata provenance and provides molecular basis of genetic resource management for C. lanceolata and the genetic improvement for generations. The main results are as follows:(1) The orthogonal design was used to optimize the amplification of the reaction system, and the suitable ISSR-PCR reaction system was:20μL reaction volume containing1.5mmol·L-1Mg2+,0.3mmol·L-1dNTP,0.7μmol·L-1primer,70ng DNA template,1U Taq DNA polymerase. The suitable PCR procedure was:pre denaturing at94℃for5min,38cycles of denaturation at94℃for40s, annealing for40s (different primers with different annealing temperature) and extension at72℃for2min, with7min final extension at72℃and then saved at4℃.(2) Nine primers of100ISSR primers were generated133DNA bands from40provenances of C. lanceolata, and122DNA bands were polymorphic. The percentage of polymorphic loci (PPB) within provenance ranged from39.34%to64.75%, and the Shannon’s phenotypic diversity index (HPOP) within provenance ranged from0.1850to0.3679. The percentage of polymorphic bands and the Shannon information index (Hsp) are89.86%and0.5655, respectively. Analysis of molecular variance (AMOVA) revealed that the genetic differentiation coefficient (ΦST) of40provenances was0.4651. It indicated that the different geographic provenances of Chinese fir had higher genetic diversity. The40Provenances were divided into seven major geographical provenance regions based on the UPGMA cluster analysis.(3) Based on the results of this study, The existence of significant genetic differentiation among Chinese fir provenances. This is due to the system during the development of Chinese fir, large differences inhabitant distribution and more exist among provenances mountains, rivers produce barrier disruption caused by gene flow, and therefore carry enormous potential for genetic improvement Chinese fir seed source selection. This implies that high generation should pay attention to the genetic improvement of C. lanceolata provenance of genetic variation between the materials collected to prevent narrowing of the genetic base of breeding populations, in order to obtain a greater genetic improvement effect. |
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