The effect of culture shaking on microspore embryogenesis and embryonic development in Pakchoi (Brassica rapa L. ssp. chinensis)

The aim of this work was to study the effect of shake culture on microspore embryogenesis and embryonic development in Pakchoi (Brassica rapa L. ssp. chinensis). All of the seven genotypes screened responded positively to shake culture. The ideal culture shaking frequency was found to be between 40 rpm and 50 rpm, which increased embryo production by 11.6–69.37% and increased the rate of cotyledon shaped embryos by 3.14–22.67% in comparison to embryos not shaken. Results indicated that shaking promoted morphogenesis of the embryos, and shorten the culture time 1–4 days. The embryos with culture shaking reached a higher plant regeneration rate.

► The frequency of embryogenesis of was increased in Pakchoi by shaking.
► Early stage embryos grew promptly and easily develop into cotyledon shaped embryos.
► Synchronism of embryo development was improved and the culture duration was shorter.
► The ideal condition was a shaking frequency at 40–50 rpm.