虹吸输铁对黄化苹果叶片光合参数及细胞器结构的影响

该研究以红富士苹果品种为材料,通过虹吸输入铁肥的方式,设置输铁液(600倍FeS04·7H20)处理并以输离子水和不输液为对照,观察了处理后苹果树的复绿情况,测定了叶绿素含量、光合参数、进行了叶绿体、线粒体超微结构的电镜扫描。结果表明:输铁后10 d,树体复绿情况明显,复绿等级由2.01变为0.53,复绿的叶片叶绿素含量有显著增加,增幅达到200%。同时,净光合速率提高了68%、蒸腾速率提高了21%、气孔导度提高了49%,胞间CO2浓度降低了100%。输铁处理后的单个细胞叶绿体个数比对照有显著增加,且个体更饱满,淀粉粒和嗜锇颗粒有明显减少;基粒片层结构规律整齐,基质清晰,被膜结构完整,线粒体内嵴清晰度高,数量增多。在输铁处理后,苹果树体复绿明显,叶绿素合成能力恢复,叶绿体、线粒体被膜结构均得到修复,表明用虹吸的方法将铁肥输入树体对苹果缺铁黄化病有很好的疗效。

Effects of Fe fertilizer siphon transfusion on photosynthetic parameters and organelle structure of iron chlorosis in apple trees

Taking Fuji Apple(Malus pumila)as the testing variety and effects of Fe fertilizer into apple through siphon, three treatments were set, including: infusion of Fe fertilizer(600 times FeSO₄·7H₂O)into apple tree through siphon, infusion of deionized water and CK(no treatment). Retrieved green leaves were observed and chlorophyll content and photosynthetic parameters were measured. Ultra microstructure of chloroplast and mitochondria were observed by electron microscopic scanning. In Fe fertilizer treatment, greening levels changed from 2.01 to 0.53 and the chlorophyll contents were increased even by 200%. Meanwhile, net photosynthesis rate was increased by 68%, transpiration rate was increased by 21%, and stomatal conductance was increased by 49%, while the intercellular CO₂ concentration was decreased by 100%. Compared to infusion of deionized water treatment and CK, in Fe fertilizer treatment, the chloroplast number was increased with larger size; and the number of starch granules and osmiophilic granules were decreased; grana lamellae structure was more clear, as well as the mitochondrial crista with more quantity. After Fe fertilizer applied, the yellow leaves retrieved green again obviously. And the synthesize of chlorophyll was improved, and the membrane structure of chloroplast and mitochondrion were recovered. In conclusion, Fe fertilizer infused into Fuji apple through siphon can correct chlorosis.