Investigation On Germplasm And Genetic Diversity Of Pelodiscus Sinensis In Jiangxi Province

Pelodiscus sinensis, which is one of Chinese special economic aquatic products, has important nutritional value and medicinal value. However, so far, the studies of Pelodiscus sinensis focused on morphology, breeding performance and disease etc. But the studies about its germplasm resousces were few. The distribution of main culture enterprises, germplasm and culture model of Pelodiscus sinensis in Jiangxi Province were investigated in this paper. Thirteen morphological parameters of six culture groups from different enterprises were measured, and six different groups' germplasm were analyzed. Moreover, we not only used two molecular methods (RAPD and ISSR) to study the genetic diversity of five populations, but also used SCAR technique to study specific molecular markers of five populations. The results were as follows:(1)The result of investigating germplasm and culture method of Pelodiscus sinensis in Jiangxi Province showed that (ⅰ)the culture enterprises existed all over the province, but the enterprises which had a certain scale mainly distributed in Nanfeng, Lichuan, Yushan, Yongxiu, Yugan, Jinxian and Yiyang County etc.; (ⅱ)the main culture strains included Poyang Lake, Guangdong Luka, Japan, Huanghe and Taiwan Chinese soft-shelled turtle, native strains and hybrids etc.; (ⅲ)there were three types of culture models including normal temperature, controlled temperature and ecological culture model; (ⅰⅲ) the main food were formula feed, fish and shrimp, chicken liver etc.; (ⅱⅲ) The products were eggs, seeds and commercial turtle. And we analyzed morphological character of six culture groups from different enterprises. The results suggested that Yushan group was hybrid progeny of Huanghe, Japan and Taiwan Chinese soft-shelled turtle. The Yugan group was Poyang Lake Chinese soft-shelled turtle, but perrhaps it was mingled with Guangdong Luka Chinese soft-shelled turtle. The Jinxian group was a multilinemaxtures including Poyang Lake, Guangdong Luka, Japan and Huanghe Chinese soft-shelled turtle. Jingfeng, Lichuan and Yongxiu group might be Poyang Lake Chinese soft-shelled turtle, but the possibility that they mingled with other strains remained to be eliminated and needed to be studied furtherly.(2) We studied the genetic diversity and special molecular marker on five Pelodiscus sinensis'populations and got the results as follows:thirteen RAPD primers detected 110 loci, of which polymorphic loci were 89, eight ISSR primers detected 50 loci, of which polymorphic loci were 33. The analysis of these data showed that the proportion of RAPD polymorphic loci was 81%, the proportion of polymorphic loci between two populations was 33.64%-89.09%.The proportion of ISSR polymorphic loci was 66%, the proportion of polymorphic loci between two population was 32.00%-82.00%. Yongxiu population has the highest proportion and Japan population has lowest proportion. The results of RAPD analysis on Lichuan population, Yongxiu population, Huanghe population, Guangxi population and Japan population were 0.7759,0.7064,0.8476,0.8585 and 0.8864. The results of ISSR analysis on Lichuan population, Yongxiu population, Huanghe population, Guangxi population and Japan population were 0.7528,0.7244,0.8749,0.8592 and 0.9150. The two results also showed that the genetic similarity of Yongxiu population was the lowest and the genetic similarity of Yongxiu population was highest. The genetic distance of five populations, which was analyzed by RAPD, was between 0.1300 and 0.5017. The genetic distance of five populations, which was analyzed by ISSR, was between 0.1046 and 0.2116. The result of cluster analysis on the five populations' genetic distance from two methods suggested that Yongxiu population clustered with Lichuan population, and Huanghe population clustered with Japan population, but the cluster result of Guangxi population from two methods were different. The RAPD technique made Guangxi population clustered with Yongxiu population and Lichuan population, but the ISSR technique made Guangxi population clustered with Huanghe population and Japan population.(3) The specific fragments were cut, and transferred into bacterias, sequenced and designed primers. Four RAPD-SCAR markers were obtained successfully, they named as LC567, YX210, LC473, and RB1457. LC567, LC473 and RB1457 could amplify corresponding target strips by PCR in Lichuan population, YX210 and LC473 could amplify corresponding target strips by PCR in Yongxiu population, YX210 and RB1457 could amplify corresponding target strips by PCR in Yellow river population, LC473 and RB1457 could amplify corresponding target strips by PCR in Japan population. Four SCAR markers could identify five Pelodiscus sinensis populations accurately.