Inheritance and Heterosis some of Traits related to Nutritional Value and Physical Quality of Rice Grain

Rice was the main food of the people of Iran and many countries of the world. As regards to population increase and climate limitations for the cultivation of important crops such as rice, it is necessary to increase rice yield and along with nutritional value. The exploitation of heterosis is a way to increase the grain yield and quality of rice Therefore, purpose this study were evaluation of genetics structure and determination heterosis of the studied traits for breeding programs and selection suitable compounds for production of hybrid rice.

In this experiment, 24 hybrids obtained from 6 lines in 4 tasters (that according to some important traits of nutritional were crossed) were used. Hybrids and parents were evaluated a randomized complete block design with three replications based on 5 nutritional traits (antioxidant activity, phenol content, Fe and Zn elements and protein) and 7 physical qualities (percentage of broken and unbroken rice, milling recovery, chalkiness percentage of grain, length, width and shape grain) along with yield and effect of combining ability of the parents and hybrids, general and narrow sence heritabilities and heterosis of traits were estimated.

The results of analysis of variance showed that line x tester was significant for traits, indicating the non-additive effect of gene in control of traits. According to the results of general combining ability, Fajr and Gharib cultivars were recognized as the best combiner for yield and nutritional value. The components of genetic variance for the studied traits showed a greater contribution specific combining ability variance than general combining ability variance, this indicates non-additive gene effect in heritability of traits. In the present study, all traits had the high general heritability (above 95%) and the low specific heritability. Investigation of heterosis phenomenon in the studied of crosses showed the largest of dominance of variance in control of these traits.

The results of components of genetic variance and heterosis indicate role of non-additive gene in controlling nutritional value, physical and yield traits. Therefore, the best breeding program was using of heterosis and hybridization method in this study. The results of heterosis showed that for simultaneous breeding of traits such as Fe, Zn and protein along with increase percentage of unbroken rice, milling recovery, grain length and yield and reduction of chalkiness percentage of grain and percentage of broken rice can be used Sepidrud × Onda, Amol2 × Gharib, Amol2 × Fajr, Abji Bojj × Fajr, Musa-Tarom × Onda and Sadri × Onda crosses.