中文摘要：

为了解丛枝菌根（AM）真菌对花生抗Cd胁迫的作用及其机理,采用温室盆栽试验,研究了Cd胁迫下接种AM真菌对花生生长、根系形态、Cd吸收及光合生理的影响.结果显示,AM真菌能与花生形成良好的共生关系,施Cd对菌根侵染率无影响;Cd胁迫下接种AM真菌能够显著改善花生生长状况,植株体内P含量与吸收量分别提高1.16—1.52、1.22—1.79倍,叶片叶绿素相对含量平均增幅11.79%,地上部分和根系生物量分别增加7.55%—8.19%、10.86%—14.05%,同时接种处理显著增大了花生根系的根长、根表面积、根体积,降低了植株地上部分Cd含量;对于同一施Cd水平而言,菌根花生叶片的最大光化学效率（Fv/Fm）和潜在光化学效率（Fv/Fo）均显著高于非菌根植株,接种AM真菌使花生叶片的净光合速率（Pn）、蒸腾速率（Tr）和气孔导度（Gs）均显著增大,而胞间CO_2浓度（Ci）显著低于不接种处理.研究表明AM真菌可通过改变花生根系的形态结构来吸附固持重金属Cd,从而减少Cd向花生植株地上部分的转移,降低Cd胁迫对花生植株造成的伤害;另一方面,通过提高花生对矿质元素P的吸收来增加植株体内叶绿素含量及改善叶片叶绿素荧光和光合作用,增强花生抗Cd毒害的能力,进而促进花生生长,提高植株生物量.

英文摘要：

In order to understand the effect and mechanism of arbuscular mycorhizal（AM） fungi on cadmium（Cd） stress tolerance of peanut,greenhouse pot culture experiment was conducted to investigate the effect of AM fungi inoculation on the growth,root morphology,Cd uptake and photosynthetic characteristics of peanut plants under Cd stress. The results showed that symbiotic relationships were successfully established between the AM fungi and peanut root under different Cd addition levels. Under Cd stress, compared with non-inoculated plants, AM fungi inoculation significantly improved the growth of peanut plants. The P concentration and uptake of AM fungi inoculated plants increased by 1.16 to 1.52 times and 1.22 to 1.79 times,respectively. The relative chlorophyll content of AM fungi inoculated plants increased by 11.79% on average,the biomass ofaboveground and root increased by 7. 55%—8. 19% and 10. 86%—14. 05%,respectively,and the root length,surface area and volume increased. The Cd concentration in the aboveground plant parts decreased significantly. Under similar Cd addition level,compared with non-inoculated plants,AM fungi inoculated peanut plants had higher maximum photochemical efficiency（Fv/ Fm） and potential photochemical efficiency（Fv/ Fo）. The net photosynthetic rate（Pn）,transpiration rate（Tr） and stomatal conductance（Gs） of AM fungi inoculated peanut leaves increased significantly,and the intercellular CO_2concentration（Ci） of AM fungi inoculated peanut leaves was lower than that of the non-inoculated plants. The results demonstrated that AM fungi could bind and immobilize Cd within the AM fungi-plant root symbiont by changing the root morphology of peanut plants and reducing Cd translocation to the aboveground parts. Furthermore,AM fungi could alleviate the Cd stress damage on peanut plants via improving their leaf chlorophyll content, chlorophyll fluorescence and photosynthesis,and enhance the Cd stress tolerance of peanut plants,resulting in the promotion of host plant g