HOT WATER TREATMENT OF CUTTING-CANE INFECTED WITH SUGARCANE STREAK MOSAIC VIRUS (SCSMV)

Abstract

The thermal inactivation point (TIP) of SCSMV was determined by heating the infected plant sap for 10 min at 50oC, 55oC, 60oC, and 65oC. The sap was inoculated mechanically on indicator plant Dactylactonium aegypticum. The virus was detected by a reverse transcription polymerase chain reaction (RT-PCR) using specific p rimer to amplify a part of the coat protein (CP) gene. The SCSMV was detected on plants inoculated with 50oC and 55oC heat-treated sap, and was not detected in plants inoculated with sap heat-tre ated at higher temperature. This TIP was used as a guideline to treat the infected cutting-canes by ho t water treatment (HWT) to evaluate its effectivene ss in eliminating SCSMV. The temperature ranged from 52oC to 55oC and heat treatments were 10, 20, and 30 min submersion time. The results showed that elevating temperature and submersion time affected the viability and severity significantly. At an upper temperature of 53oC with longer than 2 0 min submersion time, plant death was observed. Alt hough the virus was not completely eliminated from the cutting-canes, HWT at 53oC for 10 min was able to reduce the disease severity and maintain the plant’s viability. The impact of HWT before pl anting will reduce the virus titer in plants and disease severity at the critical time of 3-4 months after planting of sugarcane thus minimizing the effect of virus infection in sugarcane.