Abstract
Recent rice cultivars in Indonesia have more than 2000 ancestors in the pedigree, and shows a very complicated pedigree. IRRI cultivars accounted for the largest part of the genetic background of the Indonesian cultivars. Five ancestors (Dee-geo-woo-gen, Cina, Latisail, Gampai, Tadukan) contributed, collectively, 46.1% of the gene pool. The Indonesian rice field having the genetic background of IR64, which was estimated from the acerage of cultivars grown in Indonesia and the kinship to IR64, was 50.6% of the total rice field. By cluster analysis using coefficients of parentage, the Indonesian cultivars were divided into 5 groups. Cisadane and Ciapus could be used as cross parents for higher yield. The IR8 group had a light grain weight, and was not a promising cross parent for high yield. Combining ability of IR8 might be different from other cultivars. The Sintanur group had a good aroma, and the Kalimas group had a poor eating quality.
