The performance of allelopathic heterosis in rice (Oryza sativa L.)

Five parental rice varieties with different allelopathic potentials were Used for diallel cross based on [P P+1, /2] design to get genetic materials including parental lines and two generations of F(1)s. The dynamics of heterosis for allelopathy in rice at different leaf stages was analyzed using additive-dominant developmental genetic model. The results showed that heterosis in both F-1 and F-2 was inhibitory to shoot and root length of lettuce (Lactuca saliva L). The heterotic effects in allelopathy varied with the leaf stage of rice accession. Simultaneous backcrossing and selfing breeding method was Used to develop the hybrid rice with allelopathic activity and the isogenic hybrid rice with non-allelopathic effect on weeds. It was also indicated that heterotic effect on allelopathy in rice was positively-significant, showing higher heterosis over mid-parent. This hybrid rice had the additive suppressive effect Oil the target weed barnyardgrass, exhibiting a large deviation from the resource competition curve. Thus we improved the genetic performance of the trait in this hybrid combination for commercial use.