Genetic Diversity Study On Sugarcane Germplasm

Germplas is the basis and guarantee of Sugarcane Cross breeding. The genetic diversity of sugarcane germplasm resources is researched, which can provide basic data for sugarcane assisted breeding. Studies on agronomic characters and quality of sugarcane germplasm resources can provide data support for sugarcane breeding. Two methods of RAPD and SSR are used in this study. The main results are as follows:(1) The six series of 48 sugarcane germplasm from Guangxi, Guangdong, Fujian, Taiwan and the United States of America. A total of 87 bands were amplified by 19 pairs of SSR primers. Eighty-four of them were polymorphic bands and the polymorphic rate was 96.55%. The number of amplified bands ranged from 2 to 8, with 4.58 average amplified bands for each primer. The polymorphism information content (PIC) value of SSR primer ranged from 0.34 to 0.93 with a mean value of 0.64. A total of 184 polymorphic bands were detected by 21 RAPD primers, and the polymorphic rate was 100%. The number of bands amplified by each primer ranged from 3 to 16. There were average 8.76 bands amplified for each primer. The PIC value of RAPD primer was ranged from 0.53 to 0.97 with a mean value of 0.86. The clustering results of SSR, with the genetic similarity coefficient of 0.70,48 sugarcane clones were divided into three categories. First has six ROC varieties. The second class has three varieties, seven, eight Yacheng varieties,10 Funong varieties, five USA varieties, five Guangdong varieties. The third, there are two ROC and two Guitang varieties. The clustering results of RAPD, with the genetic similarity coefficient of 0.70, the 48 sugarcane were divided into three categories. First class has four ROC varieties, the second class has four ROC,9 Guitang, four Yacheng varieties. The third class included 4 Yacheng,10 Funong varieties,5 USA and 5 Yuetang varieties.(2) RAPD analysis of 92 sugarcane germplasm materials:50 RAPD primers were amplified to 92 tested sugarcane materials DNA samples by PCR, a total of 547 bands were amplified, on average, each primer was amplified 10.9. There are 530 polymorphic and the percentage of polymorphic rate was 96.9%. According to the clustering results, the 92 sugarcane materials were divided into two categories, each category is divided into two sub categories, according to the results of RADP amplification, the similarity coefficient calculated between the 92 cultivars of sugarcane. The results showed that the genetic similarity coefficient from 0.72 to 0.92, the genetic similarity coefficient between TD8 and TD4 is highest, which is 0.92. The similarity coefficient among the vast majority of materials is greater than 0.7(3) Comparative analysis of sugarcane germplasm resources between USA and domestic cultivars:28 RAPD primers and 8 pairs of SSR primers used to 25 sugarcane cultivars. The 25 RAPD were amplified 132 bands, which polymorphic bands were 102, and the percentage of polymorphic was 77.3%. The average bands amplified for each primer was 5.28 bands a total of 56 bands were amplified by SSR primers, the average of each primer were 7 bands, of which 48 were polymorphic bands, the percentage of polymorphic bands was 85.7%. The USA sugarcane varieties have rich polymorphism, and GUC33 polymorphism is the highest. According to the RAPD clustering graph, the 28 sugarcane materials can be divided into two categories. The first class is only a material Funong 39. Second class including 27 from the United States and China different regions of sugarcane materials, of which second categories from the genetic similarity between the United States is more close, such as GUC1 and GUC2, GUC21 and GUC23. According to the SSR clustering chart, we can see that the material is divided into two categories. The first category includes 26 sugarcane materials from different parts of the United States and China, and second of the two sugarcane materials from the United States. First class since the materials between the genetic similarity is more close, such as GUC1 and GUC2, GUC21 and GUC23, which is consistent with RAPD. There was very high genetic similarity coefficient between GUC34 and CP84-1198 and the two materials may be a certain kinship.(4) The agronomic characters and quality of introduced Germplasm from USA showed that GUC31 had the most effective stem number, which has middle stem and the highest Single stem. This material has high potential yield, and it was convenient for mechanical harvesting.