Dominant nuclear male sterility in sorghum induced by hybridization of two fertile lines

Direct and reciprocal F1 hybrids, F2 and BC generations, as well as the progenies from sib-crosses, selfed fertile siblings and testcross hybrids obtained from the sorghum cross Milo-145 × SK-173 were grown in the field in an experiment conducted in Russia. Plants with partial or complete male sterility were observed in direct and reciprocal crosses of Milo-145 × SK-173 crosses. Segregation for male sterile and male fertile plants corresponding to a 1:1 ratio was observed in the BC1 generation. In progenies obtained by crossing male sterile to male fertile siblings, segregation of sterile and fertile plants was observed. In the BC2 generation, families segregating for sterile and fertile plants in a 1:1 ratio, as well as male sterile families were obtained. After crossing sterile plants from BC1 to KVV-181, a restorer line derived from the Milo cytoplasm, male fertility was completely restored.