| Jatropha curcas Linn. (Euphorbiaceae), a multipurpose bush-small tree, has perhaps the highest potential among oil-bearing tree species. This species was characterized by its short gestation period, drought endurance, low cost of afforestation, and high oil content. In addition, energy supply is becoming increasingly problematic with the escalating price of petroleum and renewable biomass enery, Jatropha curcas Linn has caused widespread concern.In order to provide new evidence for selecting, breeding and the germplasm resources conservation of Jatropha curcas Linn provenance, the 10 wild populations totally 200 individuals from YunNan and SiChuan were investigated by the technique of cpSSR analysis and compared on the genetic diversity. Major results were as follows:1. The improved CTAB method was used to extract DNA from the leaves of Jatropha curcas Linn. This method was the best and perfectly suitable for cpSSR analyze.2. Through comparing with the optimized experiments of five factors(such as template DNA,dNTP,primer,Taq DNA polymera and Mg2+ concentration)which influenced PCR amplification, an optimized reaction system for cpSSR-PCR analysis was established. PCR was performed in a 20μL reaction system mixture with 2.00mmol/L Mg2+,2U/μL Taq DNA polymera,0.2mmol/L dNTP,0.2μmol/L primer,35ng/μL template DNA. The temperature profile for PCR was 95℃for 5min,followed by 36 cycles of 94℃for 30s,52℃for 30s,and 72℃for 1min,and was terminated with a 5 min DNA extension step at 72℃;save at 4℃.3.12 cpSSR primers selected from 25 were applied to cpSSR analyze of 10 wild populations.25 DNA locus were amplified through 12 cpSSR primers among which 22(76.28%) were polumorphic respectively, which showed that these populations have better ability to adapt to the environment. The above results indicated 10 wild populations Jatropha curcas Linn had abundant genetic diversity. Among them, SCHL has the highest genetic diversity (0.6269) and YNLS has the lowest genetic diversity(0.4095).4. The genetic variation in the population of Jatropha curcas Linn was detected by cpSSR with the observed numner of alleles A=1.9840; effective number of alleles Ae=1.7136; Nei's diversity H=0.4020 and Shannon index I=0.5767. Furthermore, Hs=0.4051, DST= 0.0357. AMOVA based on cpSSR data showed that greater amount of genetic variation was partitioned within populations(91.02%) rather than among populations(8.98%). All of this showed that the genetic variation was mainly from individuals in population. It was also noticed that gene flows Nm=3.0585 whitch was larger than 1.0. It was showed that there was gene flows among populations.5. The UPGMA dendrogram of cluster was based on cpSSR amplied bands. Among 10 different wild populations of Jatropha curcas Linn, the genetic identity were 0.8127 to 0.9798 and the genetic distance were 0.0204 to 0.2073. The genetic identity between SCLB and XSBN was nearest(I=0.9798) and those between YNLS and SCJH was farthest (1=0.8127); the genetic distance between SCLB and XSBN was smallest(D=0.0204) and those between YNLS and SCJH was largest (D=0.1614). The results of UPGMA showed that SCJH and SCHPZ classied into a group,3 populations from SiChuan(SCHL,SCHD and SCLB) and 5 populations from YunNan(YNSB,YNLX,YNPR,XSBN and YNLS) classied into another group.This may be related to that SiChuan Jatropha curcas Linn populations was introduced from YunNan. The UPGMA dendrogram of cluster showed the 10 wild populations of Jatropha curcas Linn were not corrected,which their genetic relationships were distant.
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