A study was conducted on culture of isolated microspores of baechumu, a hybrid between Chinese cabbage and Korean radish. Flower buds 2-5 ㎜ in length were collected, surface-sterilized and macerated in the mortar with washing solution. The crude microspore solution was filtered through the 45 ㎛ sieve and the filtrate was centrifuged 3 times at 100g for 3 minutes by changing the washing solution. The final pellet was diluted in cultural media in several microspore densities and the microspore solutions were placed by 2㎖ to the 60×15 ㎜ Petri-dish, then treated with the high temperature of 32.5℃ for 1 to 3 days before culture at 25℃.
Embryoids and calli were induced from microspores under some cultural conditions. The BS medium supplemented with 13% sucrose was better than the 1/2 B5 as the washing solution in the embryoid induction. As the culture medium, the NLN with 13% sucrose was more efficient than the 1/2 NLN. The density of microspore of 10^5/㎖ was better, as compared with the higher or lower density. The 3-day treatment at 32.5℃ induced more embryoids than the 1- or 5-day treatment. Fourteen plants obtained from 114 embryoids were assorted to 1 haploid, 9 diploids, 2 tetraploids and 2 chimeras by the chromosome number of the root tip.
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