AM真菌和外源磷对铝胁迫下油茶幼苗光合生理的影响

Effects of AM Fungi and Exogenous Phosphorus on Photosynthetic Physiology of Camellia oleifera Seedlings Under Aluminum Stress

以一年生普通油茶实生苗和4种AM真菌为试材,采用盆栽试验,在施用磷(0、30、60、120 mg·L^(-1))、铝(0、1、2、3 mmol·L^(-1))组合处理下培养8个月,研究了AM真菌和外源磷对铝胁迫下油茶幼苗光合生理的影响,以期为开展外源磷和丛枝菌根缓解铝胁迫的相关机理研究提供参考依据。结果表明:4种AM真菌中摩西斗管囊霉侵染率最高,接菌幼苗其净光合速率、气孔导度、蒸腾速率、叶绿体色素含量、类胡萝卜素及CO_(2)利用效率较对照分别提高295.19%、381.48%、297.86%、57.63%、172.75%和142.00%;在铝胁迫下,接种摩西斗管囊霉能提高油茶幼苗光合生理响应的敏感性,其高浓度铝胁迫下的净光合速率、气孔导度、蒸腾速率、叶绿体色素含量、非光化学淬灭参数、非光化学淬灭的量子产量、根部干质量和地径较高;添加浓度120 mg·L^(-1)以下的外源磷能缓解铝胁迫对摩西斗管囊霉菌根苗光合生理的影响,主要是通过显著提高其净光合速率和根部干质量。综上,土壤铝害抑制油茶的光合作用从而影响其生长发育,外源磷和丛枝菌根真菌对油茶光合生理的增效作用能有效缓解铝胁迫的影响。

The One-year-old common Camellia oleifera seedlings and four species of arbuscular mycorrhizal fungi(AMF)were used as experimental materials,the pot experiment was conducted.The seedlings were cultivated for 8 months under combinations of phosphorus(0,30,60,120 mg·L^(-1))and aluminum(0,1,2,3 mmol·L^(-1))treatments.The effects of AMF and exogenous phosphorus on the photosynthetic physiology of Camellia oleifera seedlings under aluminum stress were studied,in order to provide reference for further research on the mechanisms of exogenous phosphorus and arbuscular mycorrhizal fungi in alleviating aluminum stress.The results showed that among the four AMF species,Funneliformis mosseae had the highest infection rate.Inoculating seedlings with Funneliformis mosseae increased the net photosynthetic rate,stomatal conductance,transpiration rate,chlorophyll content,carotenoids,and CO_(2)utilization efficiency by 295.19%,381.48%,297.86%,57.63%,172.75%and 142.00%,respectively,compared to the control.Under aluminum stress,inoculation with Funneliformis mosseae increased the sensitivity of Camellia oleifera seedlings′photosynthetic physiology response.The net photosynthetic rate,stomatal conductance,transpiration rate,chlorophyll content,non-photochemical quenching parameters,non-photochemical quenching quantum yield,root dry weight,and underground stem were higher under high aluminum stress.Exogenous phosphorus addition at concentrations below 120 mg·L^(-1)alleviated the effects of aluminum stress on Funneliformis mosseae mycorrhizal seedlings′photosynthetic physiology,mainly by significantly increasing their net photosynthetic rate and root dry weight.In summary,soil aluminum toxicity inhibited the photosynthesis of Camellia oleifera,thereby affecting its growth and development.The synergistic effect of exogenous phosphorus and arbuscular mycorrhizal furgi formation effectively alleviated the impact of aluminum stress on Camellia oleiferaphotosynthetic physiology.