Medium, AgNO_3, Activated Charcoal and NAA Effects on Microspore Culture in Brassica rapa

摘要

Optimum conditions for the microspore embryo induction of Brassica rapa were determined in order to develop a microspore culture protocol to efficiently shorten breeding time. Each optimal condition for microspore embryo induction was dependent on thegenotypes used. The microspore embryo induction was affected by the concentration of plant growth regulators, NLN medium strength, micro element, and activated charcoal level. The NLN medium strength for an optimal condition of the microspore embryo formation of Brassica rapa was a single NLN medium strength (lx). The addition of a half strength of micro elements to a half strength (0.5 x) of NLN medium was mostly efficient for the formation of microspore embryos. When 0.1 mg L~(-1) of AgNO_3 was addedto the half strength NLN medium, the number of normal microspore embryo formation increased and the number of hyperhydric microspore embryo (HSE) decreased while the uniformity of microspore embryos was also enhanced. The addition of activated charcoalnot only increased the induction rate of microspore embryos by 200%, but also decreased the induction rate of hyperhydric embryos. These results indicate that the microspore embryo formation rate of Brassica rapa can be significantly increased with significantly reduced chances of HSE.