Study of correlation among ploidy level and steroid glycoalkaloids content in resistance in cultivated and uncultivated potato species from an in vitro genebank.

The present research was carried out with the aim to determine the correlation between ploidy level, steroid glycoalkaloids (SGAs) content and resistance against Late blight (Phytophthora infestans (Mont.) de Bary), and Colorado potato beetle (Leptinotarsa decemlineata (Say)) in cultivated and wild Solanum species preserved in the Potato Gene Bank of Czech Republic. In this study 27 species were included which consist of five cultivated and 22 wild species, with a total of 31 genotypes (four species represented by two accessions). In this study 70.97% of genotypes were evaluated as diploid, 3.23% were triploid, 19.35% tetraploid and 6.45% hexaploid as depicted from counting of chromosomes. The highest concentration, of foliage α-solanine (5,450 mg kg) and α-chaconine (9,420 mg kg) of dry matter was found in the specie S. yungasense 00070, whereas lowest 1.1 mg kg and 2.3 mg kg in S. pinnatisectum 00051, respectively, Tukey’s test of one way anova was performed for getting significance from the data obtained and found significant variation among species of steroid glycoalkaloids (SGA) content in dry weight at level of P ≤ 0.01. Leaf damages by Leptinotarsa decemlineata under field experiment circumstances were also recorded. In vitro study, S. bulbocastanum PIS 06-17 and S. bulbocastanum 00240 shown resistant to P. infestans upon inoculation of aggressive isolates and strong resistance was observed in S. stoloniferum 00295, S. sucrense 0062 and S. yungasense 0070. Nevertheless, there was no correlation of ploidy level, SGA contents and resistance to the CPB (r = 0.00) and late blight (r = 0.076) found in the investigated Solanum species.