The Effects of Different Concentrations of Nitrogen Sources on Growth of Micropropagated Potato Cultivars

The use of nitrogen in nutrient media is essential for growth and helps identify highly productive media for potato (Solanum tuberosum L.) micropropagation and adventitious shoot formation. Three potato cultivars (Agria, Marfona and Savalan cultivars) were examined for their growth response with medium containing four different levels of KNO۳ (۱, ۱.۲۵, ۱.۵ and ۱.۷۵ times as much ۱.۹ g l-۱) and NH۴NO۳ (۱, ۱.۲۵, ۱.۵ and ۱.۷۵ times as much ۱.۶۵ g l-۱). The morphogenic responses of cultivars were evaluated via measurement of root length, number of roots, shoot length, number of shoots and number of nodes per plantlet. Results indicated that the cultivars differed in their response to nitrogen source types and different concentrations. The results of both KNO۳ and NH۴NO۳ experiments indicated that N۳C۱ and N۳C۲ (۲.۸۵ g l-۱ KNO۳ and ۲.۴۷۵ g l-۱ NH۴NO۳in Agria and Marfona, respectively) had the longest shoot length. Cultivars Agria and Marfona at ۲.۳۷۵, ۲.۸۵ and ۳.۳۲۵ g l-۱ KNO۳ produced the shortest root length, but cultivar Savalan in all KNO۳ levels had the highest root length. Our findings indicated that the third concentration of both nitrogen sources (KNO۳ and NH۴NO۳) were better than other nitrogen concentrations in all cultivars for number of shoots and number of nodes. Therefore, nitrogen source media should have significant utility for shoot or other important traits in potato in vitro culture conditions.