Abstract: 【Objective】 The research objective is to evaluate the feasibility of target region amplification polymorphism (TRAP) analysis on sugarcane genetic diversity, genetic distance and the association between the genetic distance and phenotype value of sucrose content, which was based on the polymorphism of sucrose metabolism genes. 【Method】 Four fixed primers derived from candidate genes of SuSy, SPS, SAI and PPDK involved in sucrose metabolism were used in combination with nine arbitrary primers. Genetic dissimilarity (GD) was estimated by TRAP markers with 17 primer combinations among 28 sugarcane genotypes. The genetic variability and genetic distance between different genotypes were estimated based on the molecular marker data and the cluster analysis was conducted. 【Result】 A total of 170 fragments were scored and among them 64.1% i.e.109 fragments were polymorphic. The average fragments and polymorphic fragments yielded by each primer combination tested were 10 and 6.4, respectively. The GD based on polymorphism in sucrose metabolism genes estimated among a set of 28 genotypes ranged from 0.12 to 0.80. The clustering of genotypes, based on the GD of sucrose metabolism genes tested at the level of 0.49, showed four groups was obtained. Not obvious regular distribution being found between groups or within the group when referring to the Brix value in specific period in the experiment. 【Conclusion】 The results suggested that genetic diversity in the four evaluated sucrose genes was higher and the marker was rich in polymorphism. It suggested a high potential application of TRAP technique in the evaluation of sucrose content trait in sugarcane, while its relevance to the data of phenotypic brix need to be further studied.

Key words: sugarcane , sucrose metabolism genes , TRAP marker , genetic diversity