Construction of digital fingerprinting and cluster analysis using ISSR markers for sugar beet cultivars (lines)

ISSR fingerprinting and cluster analysis were conducted among 4 introduced sugar beet (B. vulgaris) cultivars from Holland and 6 lines (including 2 annual beets) from China using ISSR markers. Six stable and high polymorphic primes were selected in this study. 51 bands were obtained using ISSR -PCR with the six primers, and polymorphic rate of the bands was 86.3 %. All test varieties (lines) can be distinguished by ISSR fingerprinting using the six primes. Digital fingerprint codes were constructed by 8 polymorphic bands from ISSR primer L1 and UBC846, which could discriminate 10 cultivars (lines) completely. The result indicated that ISSR fingerprinting could identify different sugar beet varieties efficiently. The genetic similarity matrix among all 10 samples was obtained by similarity analysis using Dice algorithm with NTSYS-pc software, and similarity coefficients ranged from 0.43 to 0.83 with an average of 0.62. Cluster tree was formed using UPGMA method. Cluster analysis showed that 10 varieties (lines) were divided two groups and three subgroups. UPGMA cluster analysis showed clear genetic relationships among the 10 sugar beet cultivars. The result indicated that the cluster tree was in accordance with the character of the populations and ISSR markers could be used to estimate genetic distance between populations.