马铃薯间作体系下作物种间互作效应及丛枝菌根真菌的作用

Potato-based intercropping system has an important role in crop production in south mountain areas of Ningxia Hui Autonomous Region. Thus, it is necessary to reveal the effects and mechanisms of crop-crop interactions in enhancing crop production and soil fertility. This project focuses on potato/bean or potato/maize by using the methods of field and controlled greenhouse experiment. The methods of Phospholipid Fatty Acid (PLFA) profile composition, and the amplification of genomic DNA using small subunit ribosomal RNA (SSU rDNA) gene primers NS31 and AM1 and the 454 Sequencing™ are used to investigated arbuscular mycorrhizal (AM) fungal communities in this study. The project plans: (1) to quantify the soil characteristics of physical and chemical, biological, and microbiological parameters, and crop biomass and yield; (2) examine the effects of interaction between crops on crop yields in the potato-based intercropping system, and the response of AM fungi to the intercropping; (3) to test the effects of AMF fungi on the outcome of interacting crops in the in the potato-based intercropping system. The results will show characteristics of AM symbiosis with potato, maize and faba bean in the in the potato-based intercropping system. The project will demonstrate how AM fungi respond to intercropping, and how AM fungi play a role in the outcome of crop-crop interactions (competition or facilitation). The project will also reveal how AM fungal hyphae network mediate the crop-crop interacts potato- maize and, potato-faba bean, resulting in overyielding. The study enhances our understanding on the mechanism of overyielding in cro-crop interaction. The results would also be helpful to design sustainable cropping systems, and help to enhance potato production in the mountain areas of south Ningxia.

以马铃薯为主栽作物的农业生产体系在宁夏南部山区作物生产中有着重要地位，因而揭示马铃薯间作体系的效应及机理有着重要意义。本研究拟以马铃薯/蚕豆、玉米间作系统为对象；通过田间试验与受控实验，采用磷脂脂肪酸图谱（PLFA）、核糖体小亚基基因（SSU rDNA）高通量测序手段和多元统计方法，研究：（1）间作体系内土壤理化、生物、微生物及相关作物学特征；（2）马铃薯间作体系下作物相互作用的产量效应以及丛枝菌根真菌对马铃薯间作体系的响应；（3）丛枝菌根（AM）真菌对马铃薯间作体系作物相互作用的调节作用。研究将阐明不同间作模式下AM真菌与主栽作物的共生特点；揭示出AM真菌对间作体系的响应以及AM真菌在作物相互作用效应（竞争与互惠）中的作用；进一步明确以菌丝为桥梁的马铃薯/蚕豆、玉米间作作物种间关系变化规律及作物产量优势机制；研究结果可为合理间、套作搭配，稳定马铃薯生产力及生态系统功能提供理论依据。

以马铃薯为主栽作物的农业生产体系在宁夏南部山区作物生产中有着重要地位，因而揭示马铃薯间作体系的效应及机理有着重要意义。本研究以马铃薯/蚕豆、马铃薯/玉米间作系统为对象；通过田间试验与盆栽实验，采用磷脂脂肪酸图谱（PLFA）、高通量测序手段和多元统计方法，研究了马铃薯与玉米、蚕豆间作体系内土壤理化、生物、微生物及马铃薯相关作物学特征；马铃薯间作体系下作物相互作用的产量效应以及丛枝菌根真菌对马铃薯间作体系的响应。研究揭示出AM真菌对间作体系的响应以及AM真菌在作物相互作用效应（竞争与互惠）中的作用。研究结果表明：马铃薯、玉米间作体系下作物“超产效应”的获得，是通过提高间作体系下马铃薯、玉米产量以及提高土地当量比而获得；持续间作后，马铃薯与玉米的种间相互作用明显减弱。马铃薯与蚕豆的种间竞争力要强于其马铃薯与玉米的竞争力。间作作物种间作用显著影响了马铃薯根际土壤AM真菌的 Shannon指数，改变了马铃薯根际土壤AM真菌群落组成；但，幼套近明囊霉、球囊霉属和类球囊霉属仍为AM真菌优势属；根际土壤碱解氮、速效磷含量高低是影响马铃薯根际土壤AM真菌群落组成和多样性的主要驱动因子。间作下，玉米根际土壤AM真菌中性脂肪酸、总AM真菌生物量、AM真菌中性脂/磷脂和微生物总生物量较单作玉米根际土壤增加2.87%、2.47%、3.29%和0.94%。研究结果初步明确了以菌丝为桥梁的马铃薯/蚕豆、玉米间作作物种间关系变化规律及作物产量优势机制；研究结果为合理间、套作搭配，稳定马铃薯生产力及生态系统功能提供理论依据。