菊科几种入侵和非入侵植物种子需光发芽特性差异

对入侵菊科植物(假苍耳、薇甘菊、紫茎泽兰、飞机草)以及非入侵菊科植物(扫帚梅、天人菊、金鸡菊、麦秆菊、翠菊、黑心菊)对比研究发现,入侵组种子往往是需光发芽,即有光条件下平均高出无光条件发芽率40%(P0.01),而非入侵组的需光发芽特性不明显,即有光和无光条件下种子发芽率差异不显著(P0.05)。以入侵植物假苍耳为例对其种子需光发芽的特性研究发现:红光有利于提高种子的萌发率(萌发率为62%),而蓝光起到相反的作用(萌发率37%);当以全光的25%照射种子时,最能够促进种子的萌发(萌发率59%),更高的光强抑制种子萌发(100%光强时,发芽率为21%)。适宜浓度水杨酸SA处理(0.01mmol/L)可以起到与光照类似的效果而促进种子萌发(提高30%发芽率),而PEG和低温处理对其不存在显著影响,说明这种需光发芽的机理可能与SA处理影响种子萌发存在一定的联系。研究证实了入侵和非入侵菊科植物之间确实存在需光发芽的差异,其生理生化差异及是否有利于入侵植物的快速入侵需深入研究。

The differences in light-demanding germination features of seeds between invasive and noninvasive alien plants within Compositae

Many introducing alien plants from the family of Compositae are used as gardening or pasture materials.Some of them had became invasive plants causing serious influence to ecological environment and vegetation health,while others became useful local-like species without any bad biological influence.The reason why some Compositae plants had much higher invasive ability than others of close taxonomic relation was a hot issue in the study of biological invasion.Seed germination is the first step for colonizing...