不同轮作系统中作物根渗出物对大豆种子萌发的化感作用

Allelopathy Effect of Root Diffusate of Crops in Different Rotation Systems on Germination and Growth of Soybean Seed

为明确不同作物根渗出物对大豆种子的化感作用,用滤纸法研究了6种轮作系统中5种作物根渗出物对大豆种子发芽及芽生长的影响。结果表明:大豆种子在大豆连作(S…SS)12年区土壤中种植后,在其根渗出物中大豆种子的发芽率为63.3%,与玉米-大豆-玉米(CSC)轮作区相比(发芽率96.7%),对大豆种子萌发有明显的抑制作用。在小麦-大豆-小麦(WSW)、大豆-小麦-玉米(SWC)和玉米-大豆-玉米(CSC)轮作区种植甜菜后,与相应轮作系统中种植其它作物相比,大豆种子在甜菜根渗出物中的发芽率和发芽势几乎最低,且在所有供试轮作系统中种植甜菜后均不利于下茬大豆种子发芽后的芽生长;而在所有轮作系统中种植亚麻后,其根渗出物更好地促进了下茬大豆种子发芽,且芽长势良好。玉米除了在小麦-大豆-小麦(WSW)轮作区外,在其它轮作系统中种植后对大豆种子发芽影响不大。在玉米-大豆-玉米(CSC)、大豆-小麦-大豆(SWS)和裸地(Nudation)中小麦根渗出物利于大豆种子发芽和芽生长。总之,同一作物在不同轮作系统中种植或不同作物在同一轮作系统种植后,作物的根渗出物对大豆种子发芽和芽生长的影响有显著差异。

In order to clarify the allelopathy effect of root diffusate of different crops on soybean seeds, the effect of root diffu- sates of crop in different rotation systems on germination and sprout growth of soybean seed were tested by the filter paper method. The germination rate of soybean seed was 63.3% in the root diffusates of soybean planted in soybean continuous crop- ping for 12 years（S＇..SS） ,which indicated germination percentage of soybean seed inhibited by the soybean root diffusates of continuous cropping system in comparison with Corn-Soybean-Corn（ CSC ）rotation system with 96.7% germination. Germina- tion rate and germinability of soybean seed were almost the lowest in the root diffusate of sugarbeet in comparison with other crops planted in Wheat-Soybean-Wheat（WSW） , Soybean-Wheat-Corn（ SWC ）and CSC rotation systems, and the root diffusates of sugarbeet planted in all the rotation systems were not beneficial to growth of soybean sprouts. Germination and sprout growth of soybean seed were increased by the root diffusates of flax planted in all the rotation systems. The effect of corn root diffusate on soybean seed germination wasn＇ t significant in five rotation systems except WSW. The root diffusates of wheat planted in CSC, SWS and Nudation benefited germination and sprout growth of soybean seed. The effect of the root diffusates of same crop planted in different rotation systems or different crops planted in the same rotation system on germination and sprout growth of soybean seed was markedly different.