Molecular and morphological evaluation of potato genotypes cultivated in sandy soil

Twenty-six potato genotypes including seventeen cultivars were used to investigate the genetic diversity of potato plants (Solanum tuberosum L.) grown in Egyptian sandy soil using both morphological characteristics and molecular markers. The analysis of variance (ANOVA) of the potato yield traits and its components showed highly significant differences among the genotypes, the growing seasons and the interaction between genotypes and the growing seasons for all the studied traits. The NAP geno type gave the highest significant values for the yield traits and the highest percentage of the tuber size more than 70 mm in diameter trait. The NIZ genotype gave the highest significant value (146.5 g) for the tuber weight trait. On the other hand, OH, Cleopatra and Sophie potato genotypes showed the least significant values for tuber weight and tuber size traits. According to the two-way hierarchical cluster analysis, the potato genotypes were separated into three main cluster groups, while in the second way of the hierarchical clustering (traits clustering), the morphological traits were separated into two clusters. According to RAPD cluster analysis, the Mondial genotype was separated at the uppermost of the dendrogram apart of the other genotypes and the Red Sun genotype was separated at the lowermost of the dendrogram. The other 24 potato genotypes were separated into five clusters. Depending upon ISSR cluster analysis; the Mozart and ALF genotypes were separated apart of all other genotypes at the lowermost of the dendrogram, while the Mondial, Sophie, Liseta, NAP and Red Sun genotypes were distributed separately throughout the dendrogram. The other genotypes were separated into four clusters. Thus, it can be concluded that both morphological and molecular markers could be efficiently used to study the genetic diversity among potato genotypes. Although the morphological characteristics are affected with the environment, their results could be supported by the molecular markers results.