Molecular markers provide a useful method for genotype characterization and allow a high precision determination of the genetic relationship between cultivars and varieties. A system based on DNA sequences—which is k...Molecular markers provide a useful method for genotype characterization and allow a high precision determination of the genetic relationship between cultivars and varieties. A system based on DNA sequences—which is known as DNA barcoding—will choose one or several standard loci which can be sequenced and compared to differentiate between species. In this research, the ITS, matK, and trnH-psbA sequences were evaluated for the molecular identification of seven F. carica genotypes, generating complete sequences for the first two loci, but unable to produce bidirectional sequences by using the trnH-psbA sequence. The ITS sequence presented the highest variation rates, while the phylogeny constructed with the matK sequence obtained the highest percentage of solved monophyletic groups. Through Pearson’s correlation analysis, it was possible to determine the existence of a significant correlation between the ITS region and psbA-trnH, and the matK and psbA-trnH sequences, but not between ITS and matK. The phylogenies constructed with the ITS + matK barcodes and ITS + matK + psbA-trnH presented the highest percentage for resolution. However, considering the cost efficiency and the facilitated recovery by using PCR, the matK + ITS combination is recommended.展开更多
文摘Molecular markers provide a useful method for genotype characterization and allow a high precision determination of the genetic relationship between cultivars and varieties. A system based on DNA sequences—which is known as DNA barcoding—will choose one or several standard loci which can be sequenced and compared to differentiate between species. In this research, the ITS, matK, and trnH-psbA sequences were evaluated for the molecular identification of seven F. carica genotypes, generating complete sequences for the first two loci, but unable to produce bidirectional sequences by using the trnH-psbA sequence. The ITS sequence presented the highest variation rates, while the phylogeny constructed with the matK sequence obtained the highest percentage of solved monophyletic groups. Through Pearson’s correlation analysis, it was possible to determine the existence of a significant correlation between the ITS region and psbA-trnH, and the matK and psbA-trnH sequences, but not between ITS and matK. The phylogenies constructed with the ITS + matK barcodes and ITS + matK + psbA-trnH presented the highest percentage for resolution. However, considering the cost efficiency and the facilitated recovery by using PCR, the matK + ITS combination is recommended.
