| 摘要: |
| 【目的】探究丛枝菌根（arbuscular mycorrhizal，AM）真菌对干旱胁迫下文冠果生长和光合生理的影响，为干旱区文冠果的栽培提供技术支撑。【方法】以1年生文冠果幼苗为材料，采用盆栽控水试验，设置干旱和接菌2个因素，其中干旱处理设置正常供水（CK）、轻度干旱（T1）、中度干旱（T2）、重度干旱（T3）4个水平，接菌处理设置接种AM真菌（记作AMF）和不接种（记作NM）2个水平，进行完全组合设计，共计8个处理，测定不同处理文冠果幼苗的生物量以及叶片的色素（叶绿素a（Chl a）、叶绿素b（Chl b）、类胡萝卜素（Car））含量、光合参数（净光合速率(Pn)、 蒸腾速率(Tr)、气孔导度(Gs) 、胞间二氧化碳浓度(Ci)）和叶绿素荧光参数（最大光化学速率(Fv/Fm)、实际光化学效率(ΦPSⅡ)、表观电子传递速率(ETR)、光化学猝灭系数(qP)、非光化学猝灭系数(NPQ)），并分析了不同指标间的相关性，利用主成分分析对不同处理文冠果的表现进行了综合评价。【结果】无论接菌与否，与CK相比，干旱胁迫明显降低了文冠果幼苗的地上部和地下部分鲜质量、干质量。在同一干旱胁迫处理下，AMF处理地上部和地下部鲜、干质量均较NM处理明显增加。无论接菌与否，干旱胁迫对文冠果幼苗叶片的色素含量有明显影响，在相同干旱胁迫处理下，AMF处理的Chl a、Chl b、Car含量均高于NM处理。无论接菌与否，与CK相比，干旱胁迫处理文冠果幼苗叶片的Pn、Tr、Gs和Fv/Fm、ΦPSⅡ、ETR、qP均下降，而NPQ先上升后下降；接种AM真菌可稳定轻度干旱处理的Fv/Fm，以缓解干旱对光系统Ⅱ（PSⅡ）的伤害；干旱40 d时，NM处理Ci的变化趋势与AMF处理Ci及Pn、Gs不一致，推测干旱胁迫40 d是气孔限制转变为非气孔限制的关键节点。相关性分析结果表明，地上部和地下部的干鲜质量均与Pn呈极显著正相关，Pn与Fv/Fm呈极显著正相关。主成分分析结果显示，T1+AMF处理得分最高。【结论】干旱胁迫下，AMF处理通过激发文冠果幼苗叶片色素合成、提高净光合速率并减轻光抑制，进而降低干旱对植株的损伤，维持文冠果幼苗正常生长生理活动，其中轻度干旱胁迫下接种AM真菌的文冠果表现最佳。 |
| 关键词: AM真菌 干旱胁迫 文冠果幼苗 光合作用 叶绿素荧光参数 |
| DOI：10.13207/j.cnki.jnwafu.2025.07.009 |
| 分类号: |
| 基金项目:河南省科技攻关计划项目(232102110179)；河南牧业经济学院博士科研启动资金项目(2018HNUAHEDF018) |
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| Effects of AM fungi on Xanthoceras sorbifolium growth and photosynthetic physiology under drought stress |
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ZONG Jianwei1,2, CHANG Yawen1, ZHU Yaqi1, DENG Haifang1, CAI Yuanyuan1, YANG Yuhua1
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1.College of Arts,Henan University of Animal Husbandry and Economy,Zhengzhou，Henan 450046,China;2.Henan Key Laboratory of Unconventional Feed Resources Innovative Utilization,Zhengzhou，Henan 450046,China
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| Abstract: |
| 【Objective】The study explored the effects of arbuscular mycorrhizal fungi (AMF) on the growth and photosynthetic physiological mechanisms of Xanthoceras sorbifolium under drought stress,to provide technical support for the cultivation of plantations and the maintenance of ecological stability in arid areas.【Method】One-year-old X.sorbifolium seedlings were selected for potted water controlling experiments.Four drought levels were set:suitable moisture (CK),mild drought (T1),moderate drought (T2),and severe drought (T3).Inoculation of AM fungi (AMF) and non inoculation (NM) treatments were performed separately.A complete combination design was performed with a total of 8 treatments.The biomass,chlorophyll content（chlorophyll a (Chl a)，chlorophyll b (Chl b)，carotenoids(Car)), photosynthetic parameters（net photosynthetic rate (Pn),transpiration rate (Tr),stomatal conductance (Gs),intercellular CO2 concentration (Ci)),chlorophyll fluorescence parameters(maximum photochemical rate (Fv/Fm),actual photochemical efficiency (ΦPSⅡ),apparent electron transfer rate (ETR),photochemical quenching coefficient (qP),and non photochemical quenching coefficient (NPQ) ) of X.sorbifolium under different treatments were measured.The correlation between different indexes was analyzed,and principal component analysis was used to evaluate the performance of different treatments.【Result】Whether inoculated or not,the fresh and dry weight of aboveground and underground parts of the seedlings were reduced markedly by drought stress in comparison with CK.Moreover,the fresh and dry weights of the aboveground and underground parts of the seedlings of the AMF treatment were distinctly higher than those of the NM treatment under the same drought stress treatment.Regardless of inoculation,drought stress had an obvious effect on the photosynthetic pigment content of seedlings’ leaves.Notably,the contents of Chl a,Chl b and Car of the seedlings with AMF treatment were higher than those with NM treatment under corresponding drought.Additionally,the Pn,Tr,Gs and Fv/Fm,ΦPSⅡ,ETR,qP of leaves showed downward trend under drought stress,while the non photochemical quenching coefficient (NPQ) showed an upward trend at the beginning,followed by a return to minimum levels at the highest concentration.Notably,Fv/Fm can be stabilized with AM fungi inoculation at mild drought to alleviate the damage to photosystem Ⅱ (PSⅡ).At the 40th day of drought,the changing trend of Ci of NM treatment was inconsistent with that of Ci,as well as Pn and Gs of the AMF treatment,probably indicating that 40 days of drought stress was the key time node in the transformation of stomatal restriction into non-stomatal restriction.The correlation analysis showed that the dry and fresh weight of both the aboveground and underground parts was significantly positively correlated with Pn,and Pn was significantly positively correlated with Fv/Fm.The comprehensive ranking by principal component analysis showed that T1+AMF treatment had the highest score.【Conclusion】AMF treatment can stimulate chlorophyll synthesis,increase net photosynthetic rate and reduce photoinhibition,thereby reducing drought damage to plants and maintaining normal physiological activities.Among them,X.sorbifolium inoculated with AM fungi under mild drought stress showed the best performance. |
| Key words: AM fungi drought stress Xanthoceras sorbifolium Bunge seedling photosynthesis chlorophyll fluorescence parameters |
