Male sterility induced by chemical SQ-1, as an effective male specific gametocide in maize (Zea mays)

Abstract

Induction of male sterility by male gametocides holds great potential in utilization of heterosis aside from nuclear encoded male sterility (NMS) and cytoplasmic male sterility (CMS) applied in crop breeding. In the present study, we reported a recently synthesized gametocide SQ-1, a pyridazinone derivative used for induction of male sterility in maize. A reference dosage of chemical SQ-1 at 5.0 kg ha-1 was sprayed in five genetically unrelated maize cultivars at the plant developmental stage L8-L10 (8 to 10 leaves developed after the above-ground seedlings), and the results showed that the SQ-1 treated plants exhibited an intact female organ that remained vigorous to alien pollination, and > 90% of male sterility reached by assaying pollen viability albeit fewer seeds were residually obtained. Besides, the present data also demonstrated that the SQ-1 induced male sterility was not severely affected by different maize genotypes. Therefore, as an alternative of NMS and CMS, the gametocide SQ-1 could be a substitution approach in maize breeding program considering its rapidity and flexibility.