Abstract:

Iron （Fe） is an essential trace element for plants， which is involved in photosynthesis and affected many important life activities of Vaccinium spp.. In order to explore the influence of Fe on the important life activities of blueberry （Vaccinium spp.）， the blueberry ‘Legacy’ was used as the material， and 3 Fe environments were set： normal iron （Na-Fe-EDTA）， insoluble iron only （Fe₂O₃） and iron deficiency （without any iron element） . The relative chlorophyll content （SPAD value）， chlorophyll content and chlorophyll fluorescence parameters of blueberry were analyzed. The results showed that in 2 stress environments of insoluble iron and iron deficiency， the growth indicators， photosynthetic pigment content and SPAD were significantly lower than those under normal iron environment （P<0.05） ， while the number， growth amount， ground diameter， leaf area and leaf photosynthetic pigment content of basal branches of blueberry under insoluble iron environment were significantly lower than those in iron-deficient environment （P<0.05）. The actual photosynthetic efficiency of leaf PSⅡ under normal iron stress were higher than those under insoluble iron and iron deficiency， while the degree of photoinhibition were significantly lower than those under iron stress and iron deficiency. Leaves of seedlings were damaged and photosynthetic capacity of leaves was weakened in iron-insoluble and iron-deficient environments. The photosystem center conversion efficiency was more unstable in iron-insoluble environments than in iron-deficient environments， and blueberry leaves were the most photoinhibited. Leaf area， biomass per plant and growth of basal shoots were significantly correlated with chlorophyll fluorescence parameters （P<0.01）， and photosynthetic pigment content of leaves was significantly positively correlated with SPAD value （P<0.01）， but there was no significant correlation between photosynthetic pigment and SPAD and fluorescence parameters （P>0.01）. In conclusion， insoluble iron， iron deficiency environment made blueberry growth inhibition and resulted in a decreased leaf chlorophyll content， leaf PSⅡ stress environment reaction center absorption and conversion of light energy was abated， electron transfer and photosynthetic efficiency was lower， which provided reference for deep mining for blueberries in iron nutrient reasonable use way.

Key words: blueberry, iron, chlorophyll fluorescence, growth and development

摘要：

铁（Fe）是植物必需的微量元素，参与光合作用。为探究Fe对蓝莓（Vaccinium spp.）重要生命活动的影响，以蓝莓‘莱克西’为试验材料，设置正常铁（Na-Fe-EDTA）、只有难溶铁（Fe₂O₃）及缺铁（不外加任何铁元素）共3种铁环境，分析其苗木生长发育及其叶片相对叶绿素含量（SPAD值）、叶绿素含量、叶绿素荧光参数等的差异。结果表明，在难溶铁和缺铁2种胁迫环境下，蓝莓各生长指标、光合色素含量及SPAD值均显著低于正常铁环境（P<0.05），而难溶铁环境下蓝莓苗木的基生枝数量和生长量、地径、叶面积及叶片光合色素含量显著低于缺铁环境（P<0.05）；正常铁环境中叶片PSⅡ实际光合效率高于难溶铁和缺铁环境，而光抑制程度显著低于这2种铁胁迫环境；难溶铁、缺铁环境中的蓝莓苗木叶片受损、叶片的光合能力减弱，其中难溶铁环境与缺铁环境相比，光系统中心转换效率更不稳定，叶片受光抑制程度最高；叶面积、单株生物量、基生枝生长量与各叶绿素荧光参数间具有显著相关性（P<0.01），且叶片光合色素含量与SPAD值间呈显著正相关（P<0.01），但各光合色素和SPAD值与各荧光参数间相关性不显著。综上所述，难溶铁环境、缺铁环境使蓝莓苗木生长发育受抑制与该环境下造成叶片叶绿素含量降低有关，胁迫环境下叶片PSⅡ反应中心光能的吸收和转换减弱，电子传递受阻，光合效率降低，为蓝莓铁素营养合理利用方式的深入挖掘提供参考依据。

关键词: 蓝莓, 铁, 叶绿素荧光, 生长发育