施氮量对间作小麦蚕豆根系分泌大豆异黄酮的影响

通过盆栽和水培试验,采用小麦蚕豆间作、蚕豆单作、小麦单作3种种植方式,研究了不同生育期不同氮水平(低氮、常规氮和高氮)处理下,单、间作小麦和蚕豆根系大豆异黄酮分泌量的变化,为进一步探明间作增产和控病机制提供依据。结果表明,随作物生育期推移,小麦根系分泌大豆异黄酮数量明显减少,蚕豆根系大豆异黄酮的分泌量先增加后减少。随施氮量增加,小麦蚕豆根系大豆异黄酮分泌量均减少,且多达显著水平。与低氮处理相比,常规氮和高氮处理下,单、间作小麦大豆异黄酮分泌量分别显著减少,且多达显著水平。间作可以显著提高作物大豆异黄酮的分泌量,但间作优势仅在低氮和常规氮处理下明显,高氮处理下,单、间作小麦和蚕豆根系分泌大豆异黄酮数量差异不显著,并且这种间作效应会随生育期的推移逐渐消失。总之,间作种植和施氮量均影响作物根系大豆异黄酮分泌量,且低施氮量的影响更明显。

Effect of nitrogen application rate on root soy isoflavone exudate of wheat/faba bean intercropping system

Through pot and hydroponics experiments of wheat/faba-bean, mono-cropped faba-bean and mono-cropped wheat, soy isoflavone exudate of faba-bean and wheat were studied under different nitrogen (deficient, adequate and excessive) conditions at different growth stages. The study aimed at providing the basis for further understanding of yield increase and disease control mechanisms of intercropping systems. The results showed that with the growth of crops, soy isoflavone exudate of wheat roots decreased, while that of faba-bean first increased before decreased. With the increase of nitrogen application rate, soy isoflavone exudate of both wheat and faba-bean decreased, and most changes were significant. Compared with deficient nitrogen treatment, soy isoflavone exudates of intercropped wheat were increased respectively by 18.9% and 122.1% at stem elongation stage (60 d after sowing) under adequate and excessive nitrogen conditions. Accordingly, soy isoflavone exudate of mono-cropped wheat was increased by 28.9% and 72.7% under adequate and excessive nitrogen conditions. Crops intercropping increased soy isolavone secretion of crops, which was significant only at lower nitrogen level. Compared with mono-cropped wheat under deficient and adequate nitrogen condition at stem elongation stage of wheat (60 d after sowing), soy isoflavone exudate of intercropped wheat was significantly increased by 26.9% and 12.0%, respectively, in pot experiment, and 15.3% and 59.2% in hydroponics. Compared with mono-cropped faba-bean under deficit and adequate nitrogen rates at branching stage (60 d after sowing), root soy isoflavone secretion of intercropped faba-bean was significantly increased by 64.6%, and 11.4% in pot experiment, and 23.8% and 14.1% in hydroponics experiment, respectively. At flowering and filling stages of wheat, and flowering and pod-bearing stages of faba-bean, the similar tendency was observed. In short, both intercropping and nitrogen fertilization changed root secretion of soy isoflavone by wheat and faba-bean, which was more obvious under lower nitrogen application rate.