渗透胁迫对化感作用生物测定的影响

Effect of Osmotic Stress on Biossay of Allelopathy

以加拿大蓬水提液为供体,白菜种子为受体,设计了梯度渗透、等渗溶液以及高渗透压、低化感物质浓度3组实验;通过梯度渗透试验确定受体植物可耐受的渗透势阈值,用等渗溶液排除渗透势的干扰确定植物浸提液的化感作用及其作用强度,以高渗透压、低化感物质浓度试验初步模拟自然条件下渗透势与化感物质之间的主次关系,探讨化感作用研究中培养液渗透势对试验结果的影响。结果显示,处理液渗透势在≥-0.25 MPa范围内对白菜种子萌发和幼苗生长没有显著影响;加拿大蓬水溶性物质具有化感作用,且其化感作用主要影响小白菜幼苗的生长,而对其种子萌发影响相对较小;在渗透势相同的溶液中,只要溶质中含有部分加拿大蓬水溶性物质即可对受体植物产生化感作用。研究发现,与渗透胁迫相比,化感物质是加拿大蓬水提液中影响受体植物生长发育的主要因素。

The paper designed three experiments to research the effect of osmotic stress on bioassay of allelopathy,which were developed by the use of Brassica pekinensis L.as a recipient and water extract of Conyza canadensis（L.） Cronq.as a donor respectively.First one was the determination of osmotic threshold values of receptor in different growing developments.Compared with the same concentration of mannitol solution,the allelopathic potential of aqueous extract of donor was researched.The last experiment was a preliminary study on relationship between osmotic stress and allelopathic potential in nature conditions.The results showed that the germination and seedling growth were not significantly influenced by osmotic stress within the range of ≥-0.25 MPa of aqueous solution.The allelopathy of aqueous solution of C.canadensis was existed,and the influence of it on seedling growth was greater than that on seed germination.When the accepter plant was cultured in a series of same concentration aqueous solution with the ratio of allelochemicals increased in solute,the obvious promotion or inhibition were found even allelochemicals was part of it.And these could be the evidence of allelopathy was the main factor in comparison with osmotic stress in water extract of C.canadensis.