The Tst1 retrotransposon position variability in potato genotypes carrying different resistance to nematodes

The aim of this research was to analyse the Tst1 retrotransposon position variability and potato genome polymorphism concerning a different resistance degree to nematodes. Hybrid combinations were obtained by crossing potato genotypes carrying different resistance to nematodes. The resistance gene R occurs either in duplex (RRrr) or simplex form (Rrrr). The genotypes Vitesse (RRrr) x Monalisa (rrrr) and Tomensa (Rrrr) x Vitesse (RRrr) were cross-bred to form either F sub(1)3 or F sub(1)21 hybrid population. Based on intergene DNA polymorphism, resistance variability of potato genotypes and hybrids to nematodes has been tested. Both types of potato genotypes (resistant and susceptible) as well as hybrid combinations showed a significant variability of Tst1 retrotransposon, analysed by PCR IRAP and PCR RBIP techniques. Both techniques are based on the use of polymerase chain reaction (PCR). From a total of eighty individuals evaluated by PCR - IRAP technique, eighteen of them differed from the rest of the population by the presence of unique DNA fragments, whose number was the highest in F sub(1)3 (Vitesse RRrr x Monalisa rrrr) population. By the primer P-Tst1-01, up to 233 DNA fragments of F13 hybrid combination were recorded, which corresponded to the average of 5.8 fragments per individual. Out of these fragments, 95.3% were polymorphic. The fragments size reached 273-2400 bp. In F sub(1)21 hybrid combination (Tomensa Rrrr x Vitesse RRrr), the primer generated 299 DNA fragments that corresponded to the average of 7.5 fragments per individual, 99% were polymorphic. The fragment size reached 232-2409 bp. By the PCR - RBIP technique the primer P-Tst1-06 generated 273 DNA fragments in F13 hybrid combination that corresponded to the average of 6.8 fragments per individual. The 98.9% of these fragments were polymorphic. The fragments size was 247-258 bp. In F sub(1)21 hybrid combination, the primer generated 328 DNA fragments that corresponded to 8.2 fragments per individual. The 99.7% of these fragments were polymorphic. The fragments size reached 217-1566 bp. The Tst1 retrotransposon position variability was higher in F sub(1)3 [Vitesse (RRrr) x Monalisa (rrrr)] hybrid combination.