Caracterização molecular e citogenética de acessos de capim buffel (Cenchrus ciliaris l.)

Abstract

The Buffel grass (Cenchrus ciliaris L.) is a forage plant of great importance in the semiarid region of northeastern Brazil. It has extensive cytogenetic variability on the chromosome number. The objective was to study the genetic diversity using molecular markers ISSR, as well as perform cytogenetic characterization of 11 Buffel grass accesses and identifying apomictic accesses using molecular marker SCAR in Buffel grass accessions of BAG Embrapa Semiarid. 10 ISSR primers on 30 accessions, produced a total of 75 bands, 72 polymorphic and monomorphic 3. The genetic dissimilarity values ranged from 0.19 to 0.78. The UPGMA method grouped the accessions into seven groups. The accesses 617 and Buchuma conosite were more dissimilar and 138 and 141 the least dissimilar. For cytogenetic experiment all 11 C. ciliaris accessions showed 2n = 36. However, in the same root analyzed we observed some cells with 2n = 30 in the access 433, 2n = 32 in access 6, 2n = 34 in hits 7754, aridus, Gayndah, Grey and Biloela, and 2n = 42 in the access 617, indicating the occurrence of polissomaty. The electrophoretic patterns of the SCAR markers revealed, fragment size of 100 (20G), 300 (19G) and 600 (OPF08-600) bp. The primer OPF08-600 revealed 83%, 77% showed primer 19G and 20G primer, revealed that 90% of bands indicative of apomixis. The ISSR markers were efficient in detecting genetic variability. And the chromosomal variability (polissomaty) can correlates the high frequency of apomixis in this species. The SCAR markers allowed the preliminary identification of apomictic access for use in the breeding program, although it is the most appropriate use of another technique associated with the SCAR marker for more precise identification of apomixis.