This work aimed to study nitrogen response and sufficiency indices using some Egyptian bread wheat varieties and their F₁ hybrids in order to detect the existed genetic variabilities and genetic behaviours for grain yielding under Azospirillum and Anabeana biofertilizers. Genotypes exhibited variations in grain yieling under the effect of both biofertilizer forms. Mean performance showed that Sids 1 and Sids 7 produced higher grain yieling under Azospirillum and Anabeana inoculation. Also, F₁ hybrids resulted from hybridization between Sakha 8 × Sids 7 appeated high grain yieling under both biofertilizer forms. This indicated the superiority of these hybrids in response to biofertilizers. Azospirillum spp existed higher genotypic variations than Anabeana oryza. In addition, estimates of generation means appeared significant effects on grain yielding under the effect of Anabaena biofertilizer. Response to biofertilizers and N sufficiency in F₁ hybrids reflected the possess of different genes to their hybrids, which varying in their actions and interactions with biofertilizers which affect on expression of the genes related to grain yieling. On the other hand, biofertilizer supply forms reflecting some sort of genotype- environment interaction in some traits related to nitrogen fixation.