Electrotherapy treatment for ratoon stunting disease (Leifsoniaxyli subsp. xyli) elimination in sugar cane micro propagation

Ratoon stunting disease (RSD) is a pathology caused by Leifsoniaxyli subsp. Xyli bacterium, one of the major diseases affecting sugarcane world production. The accurate diagnosis of the disease presents some difficulties, because once noticeable, not always the symptoms are specific. Therefore, diagnostic tests should include reliable methods that ensure the health report with high sensibility, even in the asymptomatic stages of the disease in plants, such as PCR. The present study aimed to evaluate in vitro shoot tips of sugarcane by PCR-specific technique. Sugarcane plants (RB92579) with 8-11 months old were used as a source of explants (stem cuttings). After in vitro establishment, shoots were cut approximately 3 cm long and they were subjected to an electrotherapy treatment (electric currents of 20 mA and 30 mA for 15 minutes). The plant DNA material was submitted to the PCR assays with specific primers for Lxx. The PCR technique manifested itself as capable method for detection of Lxx with sensibility even in in vitro plants. Through this method was possible identify samples previously submitted to electrotherapy which did not PCR presented amplification using specific primers for Lxx. As so, PCR can be used to analyze in vitro shoot tips of sugarcane.