The sulphonylurea herbicide monosulphuron ester sodium as a special male gametocide in Brassica napus L

The sulphonylurea herbicide monosulphuron ester sodium (MES) was first used to induce male sterility in rapeseed (Brassica napus L.). Nearly 100% male sterility was achieved after a single treatment with 10 ml of 0.05-0.10 μg/ml MES solution per plant to the cultivars Zhongshuang No.9 and Zhongshuang No.11 at the uninucleate stage of the longest buds. No adverse effects on main agronomic traits and female fertility were observed. In the subsequent experiment, 48 out of 49 different accessions showed male sterility after spraying with 10 ml of 0.10 μg/ml MES solution per plant. Seven out of these 48 accessions were male sterile for the entire flowering period. Seed number per plant of these MES-treated plants was not significantly reduced compared to the controls. The hybridity was 95.5% in the case of seeds harvested from the ZS09 inbred line if sprayed twice with 10 ml of 0.10 µg/ml MES solution per plant and pollinated by the SH11 male line. These results suggest that MES is an efficient chemical hybridising agent for B. napus.