Characterization of novel sugarcane expressed sequence tag microsatellites and their comparison with genomic SSRs |
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| Authors: | L R Pinto K M Oliveira T Marconi A A F Garcia E C Ulian and A P de Souza |
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| Institution: | Centro Avançado da Pesquisa do Agronegócio de Cana, Instituto Agronômico de Campinas-IAC, Anel Viário Contorno Sul, km 321, CP 206, CEP 14001-970, Ribeirão Preto, São Paulo, Brasil, E-mail:;;Centro de Biologia Molecular e Engenharia Genética (CBMEG) –Universidade Estadual de Campinas (UNICAMP), Cidade Universitária 'Zeferino Vaz',CP 6010, CEP 13083-970, Campinas-São Paulo, Brasil;;Depto de Genética, Escola Superior de Agricultura Luiz de Queiroz (ESALQ), Universidade de São Paulo (USP), CP 83, CEP 13400-970, Piracicaba-São Paulo, Brasil;;Centro de Tecnologia Canavieira, Piracicaba-São Paulo, Brasil |
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| Abstract: | Microsatellites or simple sequence repeats (SSRs) are one of the most suitable markers for genome analysis as they have great potential to aid breeders to develop new improved sugarcane varieties. The development of SSR derived from expressed sequence tags (EST) opens new opportunities for genetic investigations at a functional level. In the present work, the polymorphism obtained with a subset of 51 EST–SSRs derived from sucest was compared with those generated by 50 genomic SSRs (gSSR) in terms of number of alleles, polymorphism information content, discrimination power and their ability to establish genetic relationships among 18 sugarcane clones including three Saccharum species (S. officinarum, S. barberi, S. sinense). The majority of EST–SSRs loci had four to six alleles in contrast to the seven to nine observed for the gSSRs loci. Approximately, 35% of the gSSRs had PIC values around 0.90 in contrast to 15% of the EST–SSRs. However, the mean discrimination power of the two types of SSR did not differ significantly as much as the average genetic similarity (GS) based on Dice coefficient. The correlation between GS of the two types of SSRs was high (r = 0.71/P = 0.99) and significant. Although differences were observed between dendrograms obtained with each SSR type, both were in good agreement with pedigree information. The S. officinarum clone IJ76‐314 was grouped apart from the other clones evaluated. The results here demonstrate that EST–SSRs can be successfully used for genetic relationship analysis, extending the knowledge of genetic diversity of sugarcane to a functional level. |
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| Keywords: | Saccharum officinarum microsatellites EST |
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