1.
Effects of lily/maize intercropping on rhizosphere microbial community and yield of Lilium davidii var. unicolor.
Zhou, L, Wang, Y, Xie, Z, Zhang, Y, Malhi, SS, Guo, Z, Qiu, Y, Wang, L
Journal of basic microbiology. 2018;(10):892-901
Abstract
Continuous cropping of lily (Lilium davidii var. unicolor) or any other crop seriously affects yield and quality. In this study, we compared continuous cropping with lily/maize intercropping. We also examined the lily rhizosphere microbes community in both sole lily cropping and lily/maize intercropping systems, by the llumina Miseq platform. Here we refer to data of recent years field experimentation of a lily/maize intercrop system in different planting configurations in the Gaolan Ecological and Agricultural Research Station. Treatments included sole crops of lily and maize, an intercrop consisting of strips of four lily rows alternating with one maize rows. The land equivalent ratio (LER) of intercrops was 1.294. The results showed that compared to sole cropping, the yield of lily in the first year of planting increased when lily was intercropped with maize. The species annotation of the high-throughput sequencing experiment showed that there was no difference in the diversity of the lily rhizosphere soil microbes on phylum taxonomic level, but the relative abundance of some genus changed obviously. The relative abundance of harmful fungus Fusarium spp. and, Funneliformis spp., decreased, and the relative abundance of beneficial bacteria Sphingomonas spp. and, Nitrospira spp., increased. In addition, we found that Lecanicillium spp., appeared only in the intercropping lily rhizosphere soil and sole cropping maize rhizosphere soil. In conclusion, the findings indicated that lily/maize intercropping could change soil microenvironment, and affect the diversity and structure of microorganism community in lily rhizosphere, with further beneficial effect on the yield of lily.
2.
Plant-plant-microbe mechanisms involved in soil-borne disease suppression on a maize and pepper intercropping system.
Yang, M, Zhang, Y, Qi, L, Mei, X, Liao, J, Ding, X, Deng, W, Fan, L, He, X, Vivanco, JM, et al
PloS one. 2014;(12):e115052
Abstract
BACKGROUND Intercropping systems could increase crop diversity and avoid vulnerability to biotic stresses. Most studies have shown that intercropping can provide relief to crops against wind-dispersed pathogens. However, there was limited data on how the practice of intercropping help crops against soil-borne Phytophthora disease. PRINCIPAL FINDINGS Compared to pepper monoculture, a large scale intercropping study of maize grown between pepper rows reduced disease levels of the soil-borne pepper Phytophthora blight. These reduced disease levels of Phytophthora in the intercropping system were correlated with the ability of maize plants to form a "root wall" that restricted the movement of Phytophthora capsici across rows. Experimentally, it was found that maize roots attracted the zoospores of P. capsici and then inhibited their growth. When maize plants were grown in close proximity to each other, the roots produced and secreted larger quantities of 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) and 6-methoxy-2-benzoxazolinone (MBOA). Furthermore, MBOA, benzothiazole (BZO), and 2-(methylthio)-benzothiazole (MBZO) were identified in root exudates of maize and showed antimicrobial activity against P. capsici. CONCLUSIONS Maize could form a "root wall" to restrict the spread of P. capsici across rows in maize and pepper intercropping systems. Antimicrobe compounds secreted by maize root were one of the factors that resulted in the inhibition of P. capsici. These results provide new insights into plant-plant-microbe mechanisms involved in intercropping systems.