Identification of RFLP markers closely linked to the H1 gene conferring resistance to Globodera rostochiensis in potato.

Resistance to the root cyst nematode Globodera rostochiensis is an agronomic trait that is at present incorporated into most new potato varieties. Major dominant genes are available that originate from wild and cultivated Solanum species closely related to the cultivated European potato (Solanum tuberosum ssp. tuberosum). One of those genes, H1, from S. Tuberosum ssp. andigena, was mapped to a distal position on potato chromosome V using restriction fragment length polymorphism (RFLP) markers. The H1 locus segregates independently from Gro1, a second dominant gene presumably from S. Spegazzinii that confers resistance to G. Rostochiensis and which has been mapped to chromosome VII. One marker, CP113, was linked without recombination to the H1 locus.

[S.E.M. study of surface condition of ultrasonic K files]. / Etude en M.E.B. de l'état de surface de limes K ultrasonores.

The present study was not about the interest of the association of ultrasonic instrumentation with irrigation in the root canal therapy, but about the wear of the K files themselves. The results showed with the assistance of the sono-synergistic system, files are almost as clean as the sterile are. This is important for the prevention of possible contamination.