覆膜垄播及轮作蚕豆对马铃薯连作田根系分泌物及化感效应的影响

以马铃薯连作田(5a)为基础,结合化感效应生物测试,研究平畦不覆膜连作马铃薯(FP-C)、覆膜垄播连作马铃薯(RM-C)、平畦不覆膜轮作蚕豆(FP-R)及覆膜垄播轮作蚕豆(RM-R)4种栽培模式对连作田根系次生代谢物及化感效应的影响。结果表明,不覆膜连作马铃薯的根系分泌物中酯类、酚类及酰胺等常见化感物质类别的相对丰度最大,其浸提液对番茄种子萌发的综合化感效应显著强于其他处理。轮作蚕豆及覆膜垄播对马铃薯连作田根系分泌物有不同的影响,轮作蚕豆降低典型化感物质类别酯类的相对含量,增加根系分泌物成分种类;覆膜垄播减少根系分泌物中酯类、烃类、酰胺、酚酸类及醇、胺、醛等成分类别的数量,同时防止嘌呤、噻唑、香兰素及樟脑的产生;两者均可达到降低化感效应的作用,但结合更有利于马铃薯连作障碍的克服。邻苯二甲酸二丁酯、邻苯二甲酸二甲酯、2-叔丁基-6-甲基苯酚、烟肼酰胺、樟脑、香兰素、9H-黄嘌呤及鲁米诺8种物质疑似马铃薯连作田根际土壤化感成分。

Effects of Ridge-sowing with Plastic Film Mulching and Rotation of Broad Bean on Root Exudates and Allelopathic Effects in Field of Continuous Cropping Potato

Based on the field of continuous cropping potato (5a) and combined with the biological test of allelopathy, the effects of four planting patterns on root secondary metabolites and allelopathy in field of the continuous cropping potato were studied, the four patterns included flat plot without mulching and continuous cultivation potato (FP-C), ridge-sowing with plastic film mulching and continuous cultivation potato (RM-C), flat plot without plastic film mulching and rotation planting broad bean (FP-R), planting on-ridge with mulching and rotation planting broad bean (RM-R). The results showed that the relative abundance of esters, phenols, amides and other common allelopathic substances in the root exudates of FP-C group was the greatest, and the comprehensive allelopathic effect of the extracts on the germination of tomato seeds was significantly more than that of other treatments. Rotation of broad bean and mulched ridge-sowing had different effects on root exudates in field of the continuous cropping potato, Rotation of broad bean decreased the relative content of esters and increased the composition of root exudates.furrow-sowing with mulching decreased the amount of ester, hydrocarbon, amide, phenolic acid, alcohol, amine, aldehyde and other components in the root secretion, and prevented the production of purine, thiazole, vanillin and camphor. The above two methods could reduce the allelopathy effect, but the combination was more effective to overcome the obstacle of potato continuous cropping. Dibutyl phthalate, dimethyl phthalate, 2-tert-butyl-6-methyl phenol, nicotinamide, camphor, vanillin, 9h-xanthine and ruminol were suspected to be allelopathic components of potato rhizosphere soil. This study will provide a theoretical basis for overcoming potato continuous cropping obstacles in the semi-arid region of the western Loess Plateau.