Effect of nitrogen interruption on in vitro tuberization and potato microtuber storage

The effect of nitrogen interruption on in vitro tuberization and on conservation (in the dark and at 4 °C for 300 days) of microtubers obtained from potato (Solanum tuberosum L.) plants cv Désirée was studied. The research was performed in a growing room (24 °C and 18 °C during day and night respectively), in solid and liquid medium. Nitrogen was removed from the plantlets at 0, 5, 10 and 15 days starting from the 21st when inductive conditions were imposed. The nitrogen nutrition subsequently was restored until the end of the trial (57th day). Growing and productive parameters were recorded. Total nitrogen on dry matter of plants (stems + leaves) and roots was determined. The interruption of nitrogen nutrition led both to an advance of tuberization and a decrease of its length. It also induced a higher number of microtubers although it did not affect microtuber storage duration.