Effect of temperature stress on isolated microspore embryogenesis in cabbage(Brassica oleracea L.var.capitata)

In order to efficiently promote embryoid induction of cabbage in microspore culture,factors affecting microspore culture were studied on 10 genotypes of headed cabbage,including heat shock at 32.5 ℃,cold pretreatment at 4 ℃,environmental temperature and flowering period.The results showed that heat shock at 32.5 ℃ for 48 h was optimal for microspore embryogenesis of all genotypes,with genotype G10 holding the highest yield of 34.35 embryos per bud.Cold pretreatment was not effective when applied alone.In three cabbage genotypes,the effect of the combination of cold pretreatment at 4 ℃ and heat shock at 32.5 ℃ for 48 h varied with the genotypes.