嫩茎花椰菜花药和花粉培养中的胚胎发生

Embryogenesis in Anther and Pollen Culture of Broccoli (Brassica oleracea Var italica)

Futura、GV和GC三个品种嫩茎花椰菜单核阶段的花药和花粉,接种在(mg/L):①2,4-D0.1+NAA0.1+10％蔗糖;②2,4-D0.5+NAA1+BAP0.5+Kt0.5+GA_30.5+10％蔗糖的改良B_5固体和液体培养基上,给予不同温度和持续时间的热处理,最后培养在25℃光照下。接种后三周,从花药中产生出胚状体。转移到含2％蔗糖的改良B_5基本培养基上长成植株。观察了花药中花粉粒发育成胚状体的过程,分析了胚状体植物的染色体倍性。液体培养中的分离花粉粒,发育成一些膨大的胚性细胞和多细胞原胚。

Three F1 hybrid cultivars of broccoli Futura (Fu) , Green Valient: (GV) and Green Charger (GC) were used in present study to induce mi cicspcre-deii ved embryos in anthers and isolated pollens. The media used in the study are listed below (mg/L) . (a) B7. modified B5 basal medium + 2,4-D0.l + NAA0.l + 10%sucrose, pH5.8; (b) B10: modified B5 basal medium + 2,4-D0.5 + NAAl + BAP0.5 + Kt0.5 + GA3 0.5 + 10% sucrose,pH6.5;(c)B513: B5 basal medium + 13% sucrose,isolating and washing solution for pollen culture. All of the media were solidified with 0.8% agar for anther culture, but for pollen culture liquid media were used.The petri dishes were kept in the dark under various temperature treatment; (a) 25C 10 days; (b) 30C 10 days; (c) 32C 3 days, 25C 10 days;(d) 33C 1 day, 25C 10 days and (e) 35CC 1 day, 25C 10 days. All of the petri dishes were then incubated in the light at 25C.In 3-4 weeks after culture, embryoids emerged out of anther sac through splits jn the anther wall. They were then transferred to a hormone-free medium containing 2 % sucrose. After 1 month they developed into plantlets.Cyto-embryological observation showed- These embryoids developed from some of uni-nuclear microspore (pollen) in anther sac under the induction of heat treatment and hormone in media. They first swelled, then broke away from pollen outer wall, then celldivision occurred and they developed to multicellular pro-embryos and complete embryoids. 98% of embryoids plantlets had the haploid chromosome number of 9 (N - 9 ) , But through long time of growth and development and after transplant in fields, the chromosome number of these plantlets were naturally doubled, namely, 2 N = 18.After 3-4 weeks of incubation,some of the cultured pollens swelled, and then cell division and multicellular 'pro-embryos were observed.