Iron absorption by iron-efficient and -inefficient species of apples
Iron absorption by iron-efficient and -inefficient species of apples
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DOI：
10.1080/01904169809365392
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发表时间：
1998-01-01
影响因子：
2.1
通讯作者：
Baligar, VC
中科院分区：
文献类型：
--
作者：
Han, ZH;Shen, T;Baligar, VC
研究了四种苹果：小金海棠 (Malus xiaojinensis Cheng et Jiang)、M. micromalus Makino、M.transitoria (Batal.) Schneid 和 M. baccata (L.)Borkh. 在铁 (Fe) 吸收机制方面的差异。结果表明，小金M. xiaojinensis 和M. micromalus 的根CEC 高于M. tantoria 和M. baccata。这些物种的根表观自由空间（AFS）中似乎存在一个“铁库”，其中在 M. baccata 中最高。 M. xiaojinensis 和 M. micromalus 根部自由空间中的铁含量随着外部 Fe 水平（40 μM）和/或更高 pH（7.8）的变化而变化，而 M. baccata 和 M. tantoria 的根自由空间铁含量没有显着变化。小金海棠和M. micromalus的电导率高于M. baccata和M. tantoria。在铁胁迫条件下，M. xiaojinensis 使根际 pH 值降低了 2 个单位，而 M. micromalus 则降低了约 1 个单位。在Fe吸收率方面，小金海棠表现出两个吸收峰，一个在64μM以上的较高Fe浓度处，与其他试验物种相同，另一个在2μM Fe浓度处，在其他物种中未观察到。 M. micromalus 的 Fe 吸收率随着外部 Fe 浓度水平的增加而增加。获得的结果支持我们在之前的论文中得出的结论，即在实验中使用的四个物种中，M. xiaojinensis 是铁效率最高的。仅次于M. xiaojineiuis的Malus micromalus具有中等的Fe效率，表现为高CEC、高根系自由空间Fe含量、高电导率、在高pH+低Fe条件下降低根际pH的能力以及从营养液中吸收Fe的能力强。
Four apple species, Malus xiaojinensis Cheng et Jiang, M. micromalus Makino, M. transitoria (Batal.) Schneid, and M. baccata (L.)Borkh., were investigated for their differences in iron (Fe) uptake mechanisms. The results showed that M. xiaojinensis and M. micromalus had higher root CEC than M. transitoria and M. baccata. There seems to be an 'Fe pool' in the root apparent free space (AFS) of these species, being highest in M. baccata. Iron content in the root free space of M. xiaojinensis and M. micromalus changed with higher external Fe level (40 mu M) and/or higher pH (7.8), whereas that of M. baccata and M. transitoria was not significantly changed. Malus xiaojinensis and M. micromalus had higher electrical conductivity than M. baccata and M. transitoria. Under Fe-stress condition, M. xiaojinensis decreased the rhizosphere pH as much as 2 units as compared to about 1 unit with M. micromalus. With regard to Fe absorption rate, M. xiaojinensis showed two absorption peaks, one at the higher Fe concentration of above 64 mu M, which was the same as with the other test species, and another one at 2 mu M Fe which was not observed in the other species. The Fe absorption rate of M. micromalus increased with increasing levels of external Fe concentration. The results obtained support our conclusion in a previous paper that of the four species used in the experiments, M. xiaojinensis was the most Fe efficient. Malus micromalus, next to M. xiaojineiuis, was moderately Fe efficient, as evidenced by its high CEC, high root free space Fe content, high electrical conductivity, its ability to lower the rhizosphere pH under high pH + low Fe condition, and a strong ability to absorb Fe from the nutrient solution.