矫正苹果缺铁失绿症途径及机理研究

Approach to the mechanism of remeding iron eficicency chlorosis in apple trees

根系输液条件下 ,N Fe能够在短时间内有效地矫正苹果缺铁失绿症。红色邻二氮杂菲铁示踪结果表明 :二价铁肥根系输液处理时仍以二价态由根被动吸收 ,运输到根、茎、叶和主脉内 ,运输部位都是靠近形成层的木质部 ,运输速度每小时可达数十厘米。室内营养液培养的八棱海棠苗用59Fe示踪结果显示 ,根中分配的59Fe为19.3% ,叶中分配的59Fe占 70 .9% ;八棱海棠59Fe示踪结果表明 ,断 1、2、3条根59Fe在叶中分配的比例分别为5 7.9%、6 3.6 %和 6 8.0 %。经树干强力高压注射二价铁后 ,其主要沿中央木质部的导管运输 ,大部分向下运往根系并大量贮存 ;而向上运稍难 ,运输速度每小时达数百厘米 ,所以矫正缺铁失绿症的速度比根系输液慢。但由于根中贮存大量的铁 ,使铁肥持效期较长。叶面喷施铁肥有斑点状复绿现象 ,主要是铁在叶片中不易移动所致。

The best result was obtained with treatment of N-Fe 5.99×10 -3 mol·L -1 when iron fertilizer was root injected. The trace of red O-phenanthroline Fe indicated: Fe 2+ was absorbed by roots and transported to stem, leaves and main vein when iron feritilizer was root injected. Fe 2+ was transported along xylem near cambium. The speed of transportation reached dozens centimeter per hour. Trace of 59Fe with Malus micromalus cultured in nutrient solution under controlled conditions indicated: distribution of 59Fe in cutting roots and leaves was 19.3% and 70.9%, respectively. Trace of 59Fe with Malus micromalus indicated: ratio of iron distributed in leaves by cutting one, two, three roots were 57.9%, 63.6% and 68.0%, respectively. the iron fertilizer by high-pressure trunk-injection indicates:Fe 2+ was transported along the central xylem, most of Fe 2+ was transported and stored in roots. It was a little difficult for Fe 2+ to be transported upto leaves. The speed of transportation reached several hundred centimeters per hour when trunks were injected with iron fertilizer with high-pressure. Regreening of iron deficiency chlorosis trees was slower but the effect of correcting iron deficiency chlorosis lasted longer when trunks were rejected with iron fertilizer than iron fertilizer was root injected. Spotted regreening appeared by foliar spray of iron because it was difficult for iron to move in leaves.