Molecular Genetic Diversity And Alk Aloid Of Different Geographical Populations Of Trichosanthes Kirilowii Maxim.

Trichosanthes kirilowii Maxim.is also known as wild bottle gourd, which is a perennial herbaceous liana in cucurbitaceae. T. kirilowii which can be planted in most parts of China, exhibited good adaptability, so that the germplasm resource is really rich.All parts of the plant can be used as medicine that own high medicinal, and the plant keep a lasting period of leaves, so that can be used for landscaping.The study on genetic polymorphism of germplasm resources in T. kirilowii are beneficial to rational utilization of it. Molecular without the interference of external factors, which can directly reflect genetic polymorphism at DNA level, is a powerful tool to study genetic polymorphism of the T. kirilowii gourds. RAPD and ISSR markers have been popularized for their non-specialty among different genera, rapidity, simplicity and saving cost, In this study,14 samples of 8 populations of T. kirilowii were analyzed by using RAPD and ISSR markers.And the total alkaloids in pericarpium Trichosanthis of some samples were analyzed by using HPLC. The study shows the results as follows:1. The RAPD and ISSR analysis system were optimized:the concentration of buffer, dNTPs, Taq DNA Polymoerse, the template DNA and primers were 2μL,0.25 mM,1.0 U,150 ng and 0.25μM in the reaction system.2.14 RAPD primers were screened out form 145 RAPD primers for PCR amplification of 14 samples of T. kirilowii DNA, from which 156 bands were amplified from the primers. The polymorphic fragment bands and percentage were 130 and 83.33%. After the PCR amplification, the average number of bands were 11.14. The value of genetic distance indexes was estimated between 0.1451 and 0.4374 of 8 populations based on the RAPD analysis and the average is 0.2956.The polygenetic tree of the genetic relationship in 8 populations were divided into three categories.3.8 ISSR primers were screened out form 126 ISSR primers for PCR amplification of 14 samples of T. kirilowii DNA, from which 90 bands were amplified from the primers. The polymorphic fragment bands and percentage were 75 and 83.33%.After the PCR amplification, the molecular weights were between 250 bp and 2000 bp, the average number of bands were 11.25. The value of genetic distance indexes was estimated between 0.1556 and 0.4568 of 8 populations based on the ISSR analysis. The polygenetic tree of the genetic relationship in 8 populations were divided into three categories.4. The polygenetic tree of the genetic relationship in 8 populations were divided into two categories base on the RAPD and ISSR analysis. It is closely similar with the RAPD and the ISSR, comparatively,it is more similar to the front one.5. The correlative coefficient is 0.772 means of analyzing the value of GD of RAPD and ISSR, and the result came out outstanding.It showed that the application of RAPD and ISSR has very high consistency and credibility on analysis of genetic diversity in T. kirilowii. The results of 3 clusting analysis were compared. The result showed that the sidship between NX-1 and NX-2 was the nearest.6. T. kirilowii shows high genetic diversity and seemly a correlation between geographical distribution and genetic distance, nevertheless most lines within the same cluster were close in genetic distance but far in geographic sites and the mainspring of it was genetic drift.7. The T. kirilowii specimens for analysis contains 18 kinds of alk aloid. The genes decide the sorts of trichosanthes bark's alk aloid; Meanwhile,the concents of alkaloids are influenced by external environment.