马铃薯根系分泌物组分对不同种植模式的响应

Response of potato root exudate components to different planting patterns

作物根系分泌物与作物连作障碍密切相关,为寻求减小作物连作障碍的途径,在轮作(大豆-马铃薯)、固定间作(马铃薯/大豆)和马铃薯连作3种种植模式下,分离鉴定了马铃薯根系分泌物的主要组分。结果表明:与轮作处理相比,固定间作和连作处理马铃薯根系分泌物种类分别增加了13.79%和17.24%,烷烃类物质的相对含量分别增加了52.17%和52.60%,酸类物质的相对含量分别增加了65.41%和14.79%。连作处理马铃薯根系分泌物中鉴定出乙胺、N-乙基吗啉和邻苯二甲酸二丁酯的相对含量分别为1.46%、2.87%和5%,而在轮作和间作处理中均未检测到。与轮作处理相比,间作和连作处理N,N-二乙基乙酰胺相对含量分别高出123.29%和47.95%,棕榈酸相对含量分别高出23.18%和40.0%,硬脂酸相对含量分别高出27.36%和39.80%。说明大豆-马铃薯轮作可有效降低马铃薯根系分泌物组分的种类和含量。因此,生产实践中,可通过大豆-马铃薯轮作克服因某一种马铃薯化感物质累积而造成的毒害作用。

To explore the methods to reduce the continuous cropping obstacles,potato root exudate components were extracted and identified from three planting patterns of potato rotation with soybean,fixed intercropping of potato and soybean and continuous potato cropping. The results showed that compared with continuous potato cropping,root exudate components of fixed intercropping of potato and soybean and continuous potato cropping increased13.79% and 17. 24% respectively. Relative alkane contents increased by 52. 17% and 52. 60% respectively,and relative contents of organic acids increased by 65.41% and 14.79% respectively. 1.46% of ethylamine,2.87% of nethyl morpholine,and 5% of dibutyl phthalate were assayed in the root exudates from continuous potato cropping,while nothing above was detected in rotation with soybean and fixed intercropping of potato and soybean. The contents of N,N-diethyl-acetamide were 123.29% and 47.95% higher,hexadecanoic acid were 23.18% and 40.00% higher,octadecanoic acid were 27.36% and 39.80% higher in fixed intercropping of potato and soybean and continuous potato cropping,compared with potato rotation with soybean. These indicated that potato rotation with soybean can reduce the variety and content of the potato root exudate components. Therefore,it can overcome the toxic effects due to the accumulation of a certain type of potato allelochemicals by the potato rotation with soybean in the production practice.