青藏高原“黑土滩”常见毒草对甘肃马先蒿的化感作用

以青藏高原"黑土滩"典型毒草黄花棘豆(Oxytropis ochrocephala)、瑞香狼毒(Stellera chamaejasme)、黄帚橐吾(Ligularia virgaurea)、密花香薷(Elsholtzia densa)和南山蒿(Artemisia nanschanica)为供体材料,在实验室条件下测试了它们的根、茎、叶水浸提液对甘肃马先蒿(Pedicularis kansuensis)的化感作用,以期寻找对甘肃马先蒿种子萌发和幼苗生长具有生态化感抑制作用的植物种类及部位。结果表明,随着5种毒草各器官水浸提液浓度的升高,其对甘肃马先蒿化感作用增强;且同一植物在测试浓度相同的条件下,表现为叶、根的水浸提液对甘肃马先蒿种子和幼苗的抑制作用强于茎的浸提液。从5种毒草化感作用的综合表现看,黄花棘豆的叶和根、南山蒿的叶在浸提液浓度为25 g/L时对甘肃马先蒿幼苗生长的抑制作用显著大于其他毒草;当作用浓度升至100 g/L时,对甘肃马先蒿种子萌发和幼苗生长都表现出致死作用。因此,对黄花棘豆叶、根和南山蒿叶等植物器官的化感作用应作进一步的研究,将有望开发出针对甘肃马先蒿的专用生物源控制剂。

Allelopathic Effects of the Typical "Black Soil Land" Poisonous Plant on Pedicularis kansuensis in Qinghai-Tibetan Plateau

The spread and outbreak of Pedicularis kansuensis in Gansu Province is an important appearance of grassland degradation in river and headwater region of Qinghai-Tibetan plateau and it is also an important problem of the restoration of degraded grassland in Qinghai-Tibetan Plateau.Based on field investigation and allelopathy experiment to water extracts of Oxytropis ochrocephala,Stellera chamaejasme,Ligularia virgaurea,Elsholtzia densa and Artemisia nanschanica on the black soil patch,the poisonous plants and organs which have the ecological allelopathy inhibition effects to germination and seedling growth of P.kansuensis were found out.The general trend was that with the increase of concentration,the allelopathy effect was enhanced.Under the same concentration,the inhibition effects of water extracts from leaves and roots were stronger than those from seeds and seedlings.From the perspective of comprehensive performances of five poisonous weeds allelopathy effects,when the water extract concentration is 25 g/L,the leaves and roots of O.ochrocephala and leaves of A.nanschanica had stronger inhibition effects to seedling growth of P.kansuensis than other poisonous weeds.When the concentration is 100 g/L,they had the lethal effects to germination and seedling growth of P.kansuensis in Gansu.Therefore,through further researches on leaves,roots of O.ochrocephala,leaves of A.nanschanica and other plant organs,the biological source control agent which is special for P.kansuensis in Gansu Province will be hopeful to develop.