Eight Iranian and exotic rice cultivars were crossed in a half-diallele crossing system in year 2000. During the following year, parental lines as well as progenies were sown in a Randomized Complete Block Design to have seven quantitative traits evaluated. Analysis of variance showed that differences due to genotypes as well as general and specific combining abilities were significant. Presence of additive and non-additive variance was observed in crosses, so was presence of complete dominance in genetic control of tiller number. Presence of partial dominance to genetic control in time of 50% heading, and plant height were observed with their heritability derermind 68 and 61%. Presence of over-dominance for characteristics such as again full maturity time, paddy weight per plant, harvest index and period of growingwere evident. So non additive variance effect was observed to be higher than additive variance effect.
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