小麦大豆间作对大豆根系质外体铁库累积与利用的影响

Effect of Wheat/Soybean Intercropping on Fe Accumulation and Mobilization in Root Apoplast

采用根箱隔网套根的盆栽方法模拟研究了小麦 /大豆间作对大豆根系质外体铁库累积与利用的影响及其在改善大豆铁营养中的作用。分别用 30μm和 0 .4 5μm的尼龙网将聚氯乙烯制作的根箱分为根室和外室 (外室装土 ,根室不装土 ) ,模拟了大豆单作、小麦 /大豆间作两种情况。结果表明 :间作大豆根系质外体铁含量高于单作大豆 ,且差异达到极显著水平 ,分别用两种孔径尼龙网套根的间作大豆根系质外体铁含量都比单作的高出 2倍多 ;从而改善大豆铁营养 ,在两种孔径的尼龙网套根下 ,间作大豆新叶叶绿素含量、地上部及根系铁含量均显著高于单作大豆。此外在单、间作情况下 ,均为用 0 .4 5μm尼龙网套根的大豆根系质外体铁含量及根系铁含量显著低于 30μm尼龙网套根大豆 。

An investigation was carried out to test the effect of wheat/soybean intercropping on iron accumulation and mobilization in root apoplast, and its role of improving iron nutrition of soybean. There were two treatments: soybean monocropping and wheat/soybean intercropping. The plants were grown in sandy soil in pots with two compartments separated by 0.45 μm or 30 μm nylon nets, a central one for root growth and outer ones for soil. The results demonstrated that intercropping improved iron nutrition of soybean. Under the conditions that soybean roots were separated by nylon nets and intercropped with wheat the chlorophyll content of young leaves, iron content of shoot and root of soybean all were more than those of monocropping treatment; and intercropping increased the content of root apoplastic iron pools of soybean, that was two times higher than monocropping one. By the way the content of root apoplastic iron pools of soybean and wheat under 0.45 μm nylon nets were lower than under 30 μm nylon nets.