云南红豆杉种子贮藏过程中胚的变化

The Change of Embryo during the Seeds of Taxus yunnanensis Conserved in Sand

采用显微测量、石蜡切片和离体培养法研究了云南红豆杉种子在贮藏过程中胚的长度、结构和萌发率的变化,结果显示:新鲜种子胚的长度差异明显,在种子贮藏过程中胚的长度变化不明显;多数情况下,成熟种子的胚分化完全,在种子贮藏过程中胚的结构没有发生明显变化;在离体培养中,新鲜种子胚在2周左右萌发,萌发率为70%,随着贮藏时间的延长,胚的萌发率会逐渐降低。因此推测种子休眠不是由胚的生物学特性引起的;胚在种子中能较长时间的保持活力,这是长期适应的结果,但却是以损失萌发率为代价的。

The length variation, structure and seeds that conserved in sand were studied by germination rate of embryo in Taxus yunnanensis Cheng et L. K. Fu paraffin section and being cultured in vitro. The results are as follows. Their length varied greatly, and did not change as seeds were conserved in sand. Most embryos developed completely in mature seeds, and the embryo structure did not change as seeds were stored in sands. In vitro, embryos from the fresh seeds germinated in 2 weeks, and the germination rate was 70%, but the germination rate declined as seeds were stored in sand. It can be concluded that biologic characters of embryos is not a reason for seed dormancy in Taxus yunnanensis. Its embryo can keep alive in seeds for long time, which may be resulted from adaptation, but its germination rate will decrease with the store time prolonged.