Evaluation of Potato Advanced Cultivars Against Water Deficit Stress Under in vitro and in vivo Condition

Abstract: This experiment performed according to the factorial design and on the base of completely randomized design in three replications in 2007. Factor A included four levels of osmotic pressure (0,-1,-2 and-3 bar) and factor B included seven advanced potato cultivars (Agria, Savalan (397007-9), Satina, Caesar, Kennebec, Marfona and Sante). The PEG 6000 was used for exerting the water deficiency stress on the plantlets. The attributes such as germinating ability and root producing was measured. In this stage the cultivar that produced the roots, had moved to the greenhouse. The plantlets were planted in soil bed with mixed of Punce and Biolan with 1:1 v/v. The applied experimental design was factorial on the base of completely randomized design in three replications. Factor A has four levels of osmotic pressure and factor B included seven advanced potato cultivars. After two months, was harvested the mini-tubers and the attributes was measured such as mini-tuber average size, mini-tubers weight and number per plant. The variance analysis results showed that significant difference between osmotic pressure levels, cultivars and their interaction as attributes mini-tubers number and weight per plant and mini-tubers average size in 1 % probability. The Caesar and Savalan cultivars had the most number and weight of mini-tuber per plant in-1 bar and Caesar and Kennebec cultivars in-2 bar osmotic pressures. The MP, GMP, STI and MSTI selected Caesar as better cultivar in normal and stress conditions. Results of cluster analysis showed that cultivars grouped in three clusters. The first cluster included Agria, Sante and Marfona (susceptible cultivars), the second cluster Satina, Savalan and Kennebec (moderately tolerance cultivars) and the third cluster Caesar (tolerance cultivar). Key words: PEG, water stress, potato, mini-tuber, in vitr, in viv