Liu P.,Sugarcane Research Laboratory |
Liu P.,Guangxi University |
Chandra A.,Sugarcane Research Laboratory |
Chandra A.,Indian Institute of Sugarcane Research |
And 7 more authors.
Euphytica | Year: 2015
Sucrose content is one of the most important traits considered in sugarcane breeding. Since sugarcane cultivars possess >100 chromosomes (2n = 100–130) and are genetically complex polyploid and aneuploids, identification of quantitative trait loci (QTLs) associated with sucrose content is considered the best option to improve sucrose content through molecular breeding. A preliminary genetic linkage map of Louisiana sugarcane cultivar ‘LCP 85-384’ from a previous study was enriched using 65 additional polymorphism simple-sequence-repeats (SSR) primer-pairs to identify more co-segregated and homologous groups (CGs and HGs) and QTLs controlling sucrose content. Eighty-four SSR primer-pairs produced 456 markers, of which 441 were polymorphic. Both simplex (993) and duplex (225) amplified fragment length polymorphism (AFLP) and target region amplification polymorphism (TRAP) markers reported previously were also included to construct the LCP 85-384 map. These simplex and duplex markers were assigned to 108 CGs successfully using JoinMap®. This map had a cumulative genome length of 7406.3 cM that included 675 AFLP (69.8 %), 90 TRAP (9.3 %), and 202 SSR (20.9 %) markers. The 202 SSR markers were assigned to 65 CGs and 8 HGs. Based on this map, 24 putative QTLs affecting sucrose content were identified. Five QTLs were unlinked and the other 19 QTLs were located on nine CGs within four HGs. Of these QTLs, 11 had an effect in both plant-cane (20.33 %) and first-stubble (25.68 %) crops. A higher efficiency of QTLs’ identification with AFLP, TRAP and SSR markers in such a genetically complex crop, proposes its wider utility in molecular breeding in sugarcane. © 2015 Springer Science+Business Media Dordrecht (outside the USA)
You Q.,Fujian Agriculture and forestry University |
Pan Y.-B.,Sugarcane Research Laboratory |
Xu L.-P.,Fujian Agriculture and forestry University |
Gao S.-W.,Fujian Agriculture and forestry University |
And 6 more authors.
Sugar Tech | Year: 2015
Genetic diversity analysis, which refers to the elaboration of total extent of genetic characteristics in the genetic makeup of a certain species, constitutes a classical strategy for the study of diversity, population genetic structure, and breeding practices. In this study, fluorescence-labeled seven gSSR and eight EST-SSR primer pairs and a capillary electrophoresis genotyping platform were used to assess the genetic diversity among 181 sugarcane clones. The clones were sorted into 14 series based on their origin. A total of 205 polymorphic SSR alleles were identified. The mean polymorphic information content (PIC) value was 0.94 for gSSRs and 0.93 for EST-SSRs, respectively. Gene differentiation coefficient (Gst) of inter-series variation (13.71 %) was much lower than intra-series variation (86.29 %). Gene flow value (Nm = 3.15) suggested that there was no significant genetic differentiation or population structure variations among the 14 series. The 181 clones could be clustered into seven groups based on neighbor-joining cluster analysis. Three major groups, namely the USA Group, the Guangxi-Hainan-Fujian Group, and the Guangdong Group, consisted of 36, 64, and 39 clones, respectively. The genotyping data provide valuable information for selecting cross parents, designing cross combinations, and future hybrid breeding strategies. © 2015 Society for Sugar Research & Promotion