关键词: 青花菜, 游离小孢子培养, 发育途径, 出胚率

Abstract: B908 and B1092 of broccoli（Brassica oleracea L. var. italica Plenck）were used to be the materials in the research on microspore embryogenesis. The nuclear division patterns and embryo development efficiency of isolated microspores of broccoli pretreated at different temperatures were investigated under a fluorescence microscopy by using DAPI staining. Four pretreated temperatures were 25 ℃，4 ℃，32.5 ℃，or 4 ℃→32.5 ℃（combined treatment）. The results showed that the nuclear division patterns were much the same under different temperature pretreatment. The B pathway started from symmetrical division that was the main pathway. The cotyledons-shaped embryo was formed after different developmental stages，microspore divided equally，multicellular structure packaged by the exine，original embryoid，globular embryoid，heart-shaped embryoid，torpedo-shaped embryiod，cotyledons- shaped embryoid. The embryoid development efficiency of isolated microspores of broccoli pretreated at different temperatures was different. The combined treatment（4 ℃→32.5 ℃）induced the highest frequency of microspore derived embryo.

Key words: broccoli, isolated microspore culture, pathway, embryogenesis yield