Development of breeding of PIWI varieties in the Czech Republic

Abstract

Context and purpose of the study. The Czech Republic is one of the most important grape growers of PIWI varieties in the Europe, as the total area planted with PIWI varieties is almost 1000 ha. The tradition of breeding dates back to the 1960s, when Vitis amurensis was used in the breeding program. There are currently 20 PIWI varieties registered in the Czech Republic. The aim of the study was to test the markers, that are bound to Plamopara viticola and Erysiphe necator resistance loci in all Czech varieties. The obtained results will be used in the further breeding program.

Material and methods. DNA was isolated from young leaves using the DNA Plant Mini Kit (Qiagen). To detect resistance loci, SSR markers closely related to them were used: Rpv3 (UDV305, UDV737), Rpv4 (VMC7h3), Rpv7 (UDV097), Rpv10 (GF09-44, GF09-46, GF09-47), Rpv11 (VVMD27), Rpv12 (UDV340, UDV370, GF14-63), Ren3 (ScORGF15-02) and Ren9 (CenGen6). PCR was prepared with GoTaq G2 Flexi DNA polymerase (Promega). Together with the tested varieties, the reference genotypes (Rpv3,4 – Regent, Rpv7 – Bianca, Rpv10,11 – Solaris, Rpv12 – Vostorg, Ren3 and 9 – Regent) were analyzed. Fluorescently labeled primers were used and the amplicons were separated in the capillary of the genetic analyzer ( ABIPrism 310, Applied Biosystems) with Gene Trace 400ROX size standard (Carolina Biosystems). The size of the alleles was evaluated using the relevant Gene Scan software and compared with the results of the reference genotypes.

Results. Based on the analyses of resistance loci, it was found that the following loci of downy mildew are represented in the varieties: Rpv3, Rpv4, Rpv7, Rpv11 and Rpv12. The results show that only one resistance loci are present in 5 varieties, two resistance loci are present in 11 varieties, three resistance loci in 3 varieties, and even 4 resistance loci in one variety. The most interesting varieties are Marcus blanc (Rpv3, Rpv12) and Ruby Pinot (Rpv3, Rpv7, Rpv11, Rpv12). They show very high resistance to downy mildew in the field conditions. From the point of view of resistance loci to powdery mildew, these are Ren3 and Ren 9 resistance loci. In 14 varieties both resistance loci are present and in one variety only Ren3 locus, in 5 varieties these resistance loci were not detected. The highest resistance in the field conditions is provided by the varieties Savilon, Vesna, Cerason and Ruby Pinot.

Acknowledgements

The analyses were supported by the TAČR project SS06020153.