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Six Iranian and exotic rice cultivars were crossed in a half - diallel crossing system . in 1994. In the following year,Parental lines and progenies were sown in a Randomized Complete Blocks Design and 8 traits were evaluated.
Analyse of Variance showed That differences due to genotypes and general and specific combining abilities were significant,Indicating the presence of additive and non-additive variance.Relative amount of each type of variance with respect to each trait however ,was not the same resulting in different heritability estimates
Presence of partial dominance in genetic control of plant height , with hertahility value from 61 to 68% made selection for dwarfishness possible
In spite of presence of over-dominance for characteristics such as length to width ratio of brown rice there is a good chance for a successful selection for long grains, due to high heritability of 64 to 94%.
The chance of a successful selection for traits such as time of 50% heading with heritability of 24 to 37% , length to width ratio of paddy with heritability of 20 to 33% and number of tiller per plant with heritability fo full maturity time of grains, paddy weight per plant ,and harvest index, selection for these characteristics may not be successful.