Seleção de clones de batata com resistência múltipla à pinta preta e aos vírus X e Y

Abstract

The purpose of this study was to select potato clones with high agronomic performance and resistant to early blight, Potato Virus Y (PVY) and Potato Virus X (PVX). Crossings were done among progenitors carrying the Ryadg and Rx1 alleles for resistance to PVY and PVX and the cultivar 'Chiquita', which presents high levels of resistance to early blight (Alternaria solani). In the rainy season of 2004, 57 clonal families were evaluated in the field and 331 clones were selected based on tuber appearance. These clones were field evaluated in two trials in the rainy season of 2005 and 180 clones were selected for Ryadg allele with the SCAR marker designed RYSC3. Another agronomic evaluation was done in the winter season of 2006 and early blight was evaluated in the rainy seasons of 2007 and 2008. Simultaneously a CAPS marker was used to select for the presence of Rx1 allele. Combining the results from these experiments we were able to select 20 clones presenting high agronomic performance, resistance to early blight and carrying the Ryadg allele. The use of CAPS marker has practical difficulties due to production of poor amplification products to be digested with the DdeI enzyme and should be changed for another marker which shows more efficiency.