GENETIC BEHAVIOUR FOR INSECT RESISTANCE AND ANTHOCYANIN CHARACTERS IN SOME RICE GENOTYPES (Oryza saliva L.)

A study of the genetic behaviour in terms of insect resistance, grain quality and anthocyanin character was carried out during the two summer seasons 2016 and 2017. Seven diverse parents viz., Sakha 101, Sakha 104, Sakha 105, Giza 177, Black rice 1, Black rice 2 and Black rice 3 were crossed using a 7 x 7 half-diallel cross analysis without reciprocals to produce 21 F-1 crosses during 2016 season. All genotypes were evaluated during 2017 season. The findings showed that general combining ability (GCA) and specific combining ability (SCA) mean squares were significant for all the evaluated characters. The ratio of (delta(2) GCA/delta(2) SCA) variances were less than unity, which showed that the inheritance of all traits were controlled by nonadditive gene action. The best general combiner for anthocyanin was Black Rice, while the best general combiners for grain quality were Sakha 105 and Sakha 101. On the other hand, the cross Sakhal 01 x Sakha 105 recoded the highest significant and negative SCA effects for the insect resistance, while Sakha 105 x Giza 177 was the most promising for grain quality. Furthermore, the dominance (sigma D-2) genetic variance and the relative importance of SCA percent were higher than the additive genetic variance (sigma(2)A) and the relative importance of GCA percent for most of the studied characters. These findings revealed that dominance gene action largely governed the studied characteristics. The heritability values in the broad sense ranged from (85.71%) for head rice to (99.7%) for Anthocyanin in brown grain, while the heritability of narrow sense ranged between (7.9 %) for milling percentage to (82.6%) for anthocyanin in milled grains, indicating that the control of these traits were dominated by non-additive effects.