Identification of Diploid Stylosanthes seabrana accessions from existing germplasm of S. scabra utilizing genome-specific STS markers and flow cytometry, and their molecular characterization.
Mol Biotechnol
; 42(3): 282-91, 2009 Jul.
Article
em En
| MEDLINE
| ID: mdl-19214807
ABSTRACT
Stylosanthes seabrana (Maass and 't Mannetje) (2n = 2x = 20), commonly known as Caatinga stylo, is an important tropical perennial forage legume. In nature, it largely co-exist with S. scabra, an allotetraploid (2n = 4x = 40) species, sharing a very high similarity for morphological traits like growth habit, perenniality, fruit shape and presence of small appendage at the base of the pod or loment. This makes the two species difficult to distinguish morphologically, leading to chances of contamination in respective germplasm collections. In present study, 10 S. seabrana accessions were discovered from the existing global germplasm stock of S. scabra represented by 48 diverse collections, utilizing sequence-tagged-sites (STS) genome-specific markers. All the newly identified S. seabrana accessions displayed STS phenotypes of typical diploid species. Earlier reports have conclusively indicated S. seabrana and S. viscosa as two diploid progenitors of allotetraploid S. scabra. With primer pairs SHST3F3/R3, all putative S. seabrana yielded single band of approximately 550 bp and S. viscosa of approximately 870 bp whereas both of these bands were observed in allotetraploid S. scabra. Since SHST3F3/R3 primer pairs are known to amplify single or no band with diploid and two bands with tetraploid species, the amplification patterns corroborated that all newly identified S. seabrana lines were diploid in nature. Flow cytometric measurement of DNA content of the species, along with distinguishing morphological traits such as flowering time and seedling vigour, which significantly differ from S. scabra, confirmed all identified lines as S. seabrana. These newly identified lines exhibited high level of similarity among themselves as revealed by RAPD and STS markers (>92% and 80% respectively). Along with the enrichment in genetic resources of Stylosanthes, these newly identified and characterized accessions of S. seabrana can be better exploited in breeding programs targeted to quality.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sitios de Sequências Rotuladas
/
Genes de Plantas
/
DNA de Plantas
/
Fabaceae
Tipo de estudo:
Diagnostic_studies
Idioma:
En
Revista:
Mol Biotechnol
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOTECNOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Índia