Pendugaan tindak gen ketahanan terhadap virus tungro pada varietas padi=Gene action estimation of resistance gene to Tungro virus disease on rice

ABSTRAK The objective of the study is to estimate the gene action of resistance gene to rice tungro virus disease. For that purpose, three parental line i.e. Seratus Hari T-36 (resistant), Utri Merah-1 (resistant), and Cisadane (susceptible) were crossed without reciprocal to produce Fl, F2, BC1, and BC2. Population (P, Py Fv F2, RCV and BC2) from all crosses were inoculated with tungro virus by infected green leafhopper at 14 days after seedling. Then they were grown in endemic area at Tanjung-siang, Subang, West Java. Observed characteristic was visual symptom using resistant scoring index according to Hasanudin et.al. (1988) and absorbent value using ELISA test according to Koenig method (1981). The results showed that scoring index of Seratus Hari T-36 X Cisadane and Seratus Hari T-36 X Utri Merah-1 crosses adequately correspond to additive-dominance model with significantly additive effect. Utri Merah-1 X Cisadane cross adequately correspond to epistatic model. Dominance effect was found on Seratus Hari T-36 X Cisadane cross. The absorbent value result of Seratus Hari T-36 X Cisadane and Utri Merah-1 X Cisadane crosses showed the same conclusion with resistance scoring index. Keywords: rice â tungro virus â gene action â resistanc