The ثffect of خsmotic and temperature stresses on the nutrients uptake in potato genotypes under In vitro culture

In order to study the changes of nutrient uptake in potato plantlets under in vitro conditions in responce  to osmotic and temperature stresses , this research was conducted as a factorial experiment in a completely randomized block design with three replications and each experiment unit included a glass container containing five plantlets.  The first factor was osmotic stress induced by polyethylene glycol 6000 in four levels of control, 0.5-0.1, and 1.5-1.5 MPa, and the second factor was temperature at three levels of 15, 25 and 35 ° C. The third factor was plantlets of potato including three promising clones (143, 301 and 306)  and Two cultivars (Marfona and Picasso) were planted in MS medium. Eight weeks after stress’s period, the content of P, K, Ca and Na were measured. The results of analysis of variance showed that the simple effects of factors as well as their interactions at 1% level were significant on traits. Mean comparison of treatments showed that the simultaneous effects of stresses decreased the uptake of P, K, Ca but Na uptake increased. Based on the results, increasing of temperature from 15 to 35 ° C, increased the absorption of P and Na, but the amount of K and Ca were greatest  25 ° C (no temperature stress).