七种蒿属植物种子重量形状及萌发特性的比较研究

在实验室条件下 ,对 7种蒿属植物种子 (差巴嘎蒿、乌丹蒿、万年蒿、大籽蒿、黄蒿、野艾蒿和冷蒿 )进行重量、形状及萌发特性的比较研究。沙生先锋植物乌丹蒿和差巴嘎蒿的种子重量较大、形状扁平 ,这些特征是植物对流沙环境进化的适应机制之一。黄蒿种子小且呈圆形 ,具有持久土壤种子库 ,因此黄蒿抗干扰能力较强。 7种蒿属植物有 3种萌发格局 :大籽蒿、万年蒿、差巴嘎蒿和冷蒿的萌发前期快 ,后期平缓 ;野艾蒿和黄蒿整个萌发过程平缓 ;乌丹蒿早期和后期萌发平缓 ,中间快。乌丹蒿推迟萌发高峰是它比差巴嘎蒿更适应流沙环境的机制之一。从种子萌发格局分析 ,黄蒿种子具有生理后熟或休眠机制 ,大籽蒿种子萌发是典型的机会主义。黄蒿、野艾蒿和冷蒿种子具有风险分摊的萌发机制。种子重量和形状与发芽率之间无相关性 ,重量和形状则显著相关。

A comparative study on seed weight, shape and germination characteristics of 7 Artemisia species

A laboratory study was made on seed weight,shape and germination characteristics of 7 Artemisia species (A.halodendron,A.wudanica,A.sacrorum,A.sieversiana,A.scoparia,A. lavandulaefolia A frigida).Seeds of A.wudanica and A.halodendron,pioneer species in sandy land,were big and not round,which was one of the mechnisms of species adapted to drift sand.Seed of A.scoporia was small and round,which means that this species perhaps has the persistent soil seed bank,which explained the reason that A.scoporia has more strong anti-disturbing ability.There were 3 germination patterns of 7 Artemisia species: germination pattern of A.sieversiana,A.sacrorum,A.halodendron and A.frigida were rapid in the early stage and slow in the later stage,respectively.A.lavandulaefolia and A.scoparia were slow in the whole germination course.A.wudanica was slow in the early and later stages,but rapid in the middle stage.A.wudanica delayed the peak emergence of germination rate,which was its mechnism of more adaptablity in drift land than A.halodendron.Accordirg to the germination pattern,seed dormancy or post-mature was the strategy of in A.scoporia,while opportunism was the strategy of A.sieversiana.Germination of A.scoparia,A.lavandulaefolia and A.frigida had the mechanism of share survival risks.Seed weight and shape had no relationship to the germination percentage.But seed weight was significantly positively related to seed shape.