Role of arbnscular mycorrhizal fungi in small-scale sustainable agricultural crop production systems in China

摘要

The application of arbuscular mycorrhizal fungi (AMF) as biofertilizers in staple food crop production systems has been studied to derive new information on biodiversity in arbuscular mycorrhizal fungi and their relevance in crop production systems in China. The work also aimed to provide small-scale farmers with an alternative technology to increase fertilizer use efficiency and optimize the fertility of land of low productivity. A total of 155 representative soil samples were collected from fields in which various crop plants were grown in Shandong, Hebei and Liaoning provinces. Thirty-nine pure isolates and eighteen pure cultures of AMF were obtained, of which eleven pure cultures were registered in the European Bank of the Glomales (BEG). Symbiotic effectiveness of AMF in the stock center was assessed in three pot experiments. Five isolates, SP4, SP5, BEG167, BEG168 and BEG141, were more efficient in terms of P uptake and plant growth by sweet potato. To evaluate the ecophysiological attributes and stability under different soil conditions, three kinds of soil, calcareous, neutral and acid soils collected from northern (Hebei), central (Hubei) and southern (Guangdong) provinces respectively were selected for experiments. Isolates BEG168 and BEG141 were the most adaptable AMF. Six field experiments were carried out from 2001 to 2003 to test the effectiveness of the selected isolates with sweet potato. To evaluate the persistence of AMF in roots and soils, taxon-specific probes were used to monitor the inoculated fungi. The introduced AM isolates colonized sweet potato roots six weeks after inoculation as determined by PCR analysis. The yield and quality of the tubers were enhanced by inoculation with mycorrhizal fungi. Isolates BEG168, GSP4 and BEG141 increased sweet potato tuber yields by 10%. Reducing sugar content and total carotenes were also increased by mycorrhizal inoculation. The study indicates that application of mycorrhizal biotechnology may have considerable porential in sustainable agriculture in the future.