Resistance of Several Local Rice Varieties to Isolate Tungro Virus from Muara

Resistance of Several Local Rice Varieties to Isolate Tungro Virus from Muara Tungro disease is one of the important diseases in rice because it causes stunted plants and may induce significant yield losses. Planting resistant varieties is a recommended control strategy to overcome tungro disease. The research was conducted to find sources of genetic resistance from local rice varieties that can be used in breeding of tungro disease resistant varieties. The experiment was arranged in a descriptive research design with observational techniques. Observations were made on 16 local rice varieties with each variety consisting of 30 sample plants so that the number of plants used was 480 plants. The isolate of tungro virus collected from rice field in Muara, Bogor was inoculated to the test plants through the insect vector, green leafhopper (Nepothettix virescens). The results showed that the resistance of local varieties varied based on the value of disease index, disease incidence and plant height reduction. ‘TN1’ was the check susceptible variety against tungro virus, while the local rice varieties were differentiated into resistant (‘Utri Merah’), moderate (‘Karau’, ‘Bekongan’, ‘Bujang Bernai’, ‘Srogel Abang’, ‘Pulut Garu’, ‘Randu Range’, ‘Siredep’, ‘Katimpung’, ‘Pulut Sawijan’, ‘Dube’), moderate tend to be susceptible (‘Blumbungan’, ‘Tjere bandung’, ‘Sempor’) and susceptible (‘Rumbai’). All varieties can be infected (disease incidence 27 – 76%), but disease severity varies greatly (3–7). The more severe the disease, the higher the plant height reduction. ‘Srogel Abang’ is a variety that is useful for breeding rice varieties resistant to tungro disease because it showed moderate response with a low percentage of plant height reduction (36%) so that plant productivity can still be maintained.Penyakit tungro merupakan salah satu penyakit penting pada tanaman padi karena menimbulkan gejala tanaman kerdil dan mampu menyebabkan kehilangan hasil yang nyata. Penanaman varietas tahan merupakan strategi pengendalian yang direkomendasikan untuk mengatasi penyakit tungro. Penelitian dilakukan untuk mencari sumber ketahanan genetik dari varietas padi lokal yang dapat digunakan dalam perakitan varietas tahan penyakit tungro. Percobaan disusun dalam rancangan penelitian deskriptif dengan teknik observasi. Observasi dilakukan terhadap 16 varietas padi lokal dengan setiap varietas terdiri atas 30 tanaman contoh sehingga jumlah keseluruhan tanaman yang digunakan sebanyak 480 tanaman. Isolat virus tungro dari pertanaman padi di Muara, Bogor diinokulasikan ke tanaman uji melalui serangga vektor wereng hijau (Nephotettix virescens). Hasil penelitian menunjukkan bahwa ketahanan varietas lokal bervariasi berdasarkan nilai indeks penyakit, insidensi penyakit dan penyusutan tinggi tanaman. Varietas TN1 merupakan varietas pembanding dengan reaksi rentan, sedangkan varietas padi lokal dibedakan atas tahan (‘Utri Merah’), moderat (‘Karau’, ‘Bekongan’, ‘Bujang Berinai’, ‘Srogel Abang’, ‘Pulut Garu’, ‘Randu Kisaran’, ‘Siredep’, ‘Katimpung’, ‘Pulut Sawijan’, ‘Dube’), moderat cenderung rentan (‘Blumbungan’, ‘Tjere bandung’, ‘Sempor’) dan rentan (‘Rumbai’). Semua varietas dapat terinfeksi (insidensi penyakit 27–76%), tetapi indeks keparahan penyakit sangat bervariasi (3–7). Semakin berat keparahan penyakit menyebabkan penyusutan tinggi tanaman semakin tinggi. ‘Srogel Abang’ merupakan varietas yang bermanfaat untuk perakitan varietas padi unggul tahan penyakit tungro karena bersifat moderat dengan persentase penyusutan tinggi tanaman yang rendah (36%) sehingga produktivitas tanaman masih dapat dipertahankan