Indonesian

Abstract

Rahmawati Y, Sulandari S, Hartono S. 2015. Response of five rice varieties to viral infections by Rice Grassy Stunt Virus that causes rice grassy disease. Pros Sem Nas Masy Biodiv Indon 1: 1123-1126. Rice grassy stunt virus (RGSV), a member of the genus Tenuivirus, is the virus that causes rice grassy disease in rice. RGSV is persistently transmitted by the brown planthopper (BPH). Besides attack, BPH also induces hopper burn disease by drying leaves and acts as vectors of stunt disease caused by a virus. The occurrence of an outbreak of BPH and grassy stunt disease has been reported in Yogyakarta and Central Java. Stunt disease is very difficult to control. Moreover, it is very harmful because it triggers puso disease. Controlling of RGSV using resistant varieties is still restrained because no rice varieties are tolerant to RGSV. Normally, all rice varieties grown by farmers are just resistant to the vector (BPH). This study aims to determine the response of some rice varieties, which are widely grown by farmers, against viral infections by RGSV that causes stunt disease. The considered parameters were incubation period, symptoms variations, incidence and intensity of the appeared disease. This research was conducted at the Laboratory of Virology and greenhouse plants Department of Plant Pests and Diseases, Faculty of Agriculture, Gadjah Mada University in Yogyakarta. The source of inoculum was taken from Sumber Rahayu, Moyudan, Sleman, Yogyakarta. BPH was reared in the laboratory and used as a vector. Virus inoculation was performed on five rice varieties namely: Membramo, Ciherang, Inpari 13, IR64, and Situ Bagendit. The results of the research indicated that each variety has a different extent of response to rice grassy disease as all the varieties showed a different level of incidence such as Membramo varieties 85.19%, Situ Bagendit and Inpari 13 92.59%, Ciherang 96.3%, and IR64 100%. Each variety showed a different period of incubation. Symptom variations such as erect tillers, pale stiff or yellowed leaves, spotted leaves, were also varied between varieties. In Situ Bagendit, variety did not show much stunted but Ciherang caused severe symptoms as plants became very stunted.