INTERNATIONAL JOURNAL OF AGRICULTURE & BIOLOGY Full Length Article Assessment of Genetic Relationship and Diversity among Chinese Sugarcane Parental Clones using SCoT and ISSR Markers

Abstract

Abstract Sugarcane is an allopolyploid crop with ≥120 or more chromosomes, of which~5.0-10% are Saccharum spontaneum and 90-95% are S. officinarum. The genetic characteristics of sugarcane provides a complex genetic background. The objective of this study was to use two molecular marker systems, start codon targeted (SCoT) and inter-simple sequence repeat (ISSR), to assess the genetic relationship and diversity of 75 sugarcane parental clones from Chinese sugarcane breeding program. Twenty-four SCoT primers produced 227 loci, of which 200 (88.11%) were polymorphic, whereas 15 ISSR primers resulted in a total of 146 loci, with 123 (84.25%) being polymorphic. Mean polymorphism information content values of 0.8152 and 0.8361 were detected using SCoT and ISSR primers, respectively. The genetic similarity coefficients ranged from 0.542 between ROC22 and HoCP95-988 to 0.831 between ROC25 and ROC20, with a mean value of 0.687 based on SCoT+ISSR data set. The unweighted pair group method of arithmetic averages (UPGMA) clusters and principal coordinate analysis (PCA) gave similar results. The 75 Chinese sugarcane parental clones were clustered into two main groups (A and B). Group A was primarily comprised of 42 clones from all Q-series, all CP-, HoCP-, or LCP-series, all YT-series and three Erianthus arundinaceus F4 innovative parental clones, etc., while 33 parental clones of Group B contained all TT-series, all GT-series, three Saccharum officinarum species, etc. The genetic similarity was high among the Q-series, CP-series, HoCP-series and YT-series. The genetic relationship was close among TT-series, GT-series and three S. officinarum species, while the genetic similarity between YT-series and TT-series or GT-series was low. There was an abundant genetic diversity among these sugarcane parental clones however the parental clones bred by the same breeding organization have a narrow genetic basis. This information was useful for selecting crossing parents and combinations. Correlation detection between SCoT and ISSR was not significant, but highly complementary, indicating that the combination of the two marker systems could avoid biases based on a single marker