EVALUATION OF TRANSGENIC POTATO LINES RESISTANCE TO POTATO TUBER MOTH, Phthorimaea operculella (ZELLER)

The potato tuber moth, Phthorimaea operculella (Zeller), is the major destructive insect of potato. The larvae attack foliage and tubers in the field and in storage as well. Over the past years, there was a tremendous effort to produce transgenic potato cultivar that is resistant to the larval infestation of potato tuber moth. ‘Spunta’ potato cultivar was previously transformed with Bt-cry5 gene under 35S promoter construct. Three transgenic ‘Spunta’ lines, ‘Spunta G2’, ‘Spunta G3’ and ‘Spunta 6a-3’, were selected for their high resistance to PTM attack. After 14 years of storage, these three lines are subjected to in vitro micropropagation, tuberization and reevaluation. Both PCR and RT-PCR confirmed the presence of cry5 gene within ‘Spunta’ genome and its expression within potato plant tissues. Amplified fragment length polymorphism (AFLP) analysis revealed that the percentage of polymorphism among the three lines and non-transgenic ranged from 0% to 10.6%. Two lines ‘Spunta G3’ and ‘Spunta 6a-3’ were selected for field agronomical performances as steps for environmental safety as well as PTM challenge. Both lines are highly resistant to PTM compared to the control, only 3% of the yield shows susceptibility to larval penetration of the tubers.