接种真菌对马尾松幼苗抗铜性的影响

On the Impact of Inoculating with Ectomycorrhizal Fungi on the Copper Resistance of Pinus massoniana Seedlings

基于外生菌根真菌在调控植物抗重金属胁迫中的巨大潜力,比较抗铜性彩色豆马勃(Pisolithus tinctorius)菌株(Ptch)侵染马尾松形成的菌根苗与非菌根苗在铜胁迫下的生长与光合适应性差异,为利用外生菌根菌修复铜矿区废弃地提供试验依据。结果表明,铜胁迫(90μmol·L-1)处理40d后,菌根化苗的生物量以及相对含水量均大于非菌根化苗,其光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)等光合参数虽下降,但降幅明显较非菌根化苗小;同时,检测叶绿素荧光参数显示菌根化苗的热耗散增加。此外,菌根化苗还显示了较高的SOD、POD、CAT活性以及较低的丙二醛(MDA)含量。表明接种Ptch对于提高马尾松抗铜性具有正向调控作用。

In view of the great potential of ectomycorrhizal fungi in promoting resistance to heavy metal stress of host plants, we compared the growth and photosynthetic physiology of mycorrhizal plants and non-mycorrhizal hosts under copper stress with two-year-old seedlings of Pinus massoniana that were inoc- ulated with Pisolithus tinctorius （strains Ptch） to establish mycorrhizal roots. The objective of this study was to provide experimental basis for utilizing ectomycorrhizal fungi in phytoremediation of abandoned cop- per mine area. The results showed that the biomass of the organs and relative water content （RWC） of mycorrhizal pines were higher than those of non-mycorrhizal controls under copper stress （ 90 μmol · L- 1 Cu- SO4,40 d ）. The photosynthetic parameters,such as photosynthetic rate （Pn）,stomatal conductance （Gs） transpiration rate （Tr） decreased less in mycorrhizal plants than in non-mycorrhizal controls. Heat dissipation increased in mycorrhizal plants by measuring chlorophyll fluorescence parameters. In addition, the MDA content was lower and the activities of SOD,POD and CAT were higher in mycorrhizal plants than those of non-mycorrhizal seedlings. To sum up,inoculating with Ptch may be helpful for improving the cop- per tolerance of P. rnassoniana.