Effects Of Associated Cultvation On Soil Microbial Diversity In Rhizosphere And Endophytic Microbial Diversity In Root Of Tomatoes

To explore and utilize beneficial microbial resources and their functions against continuous cropping obstacles of tomatoes for developing sustainable agriculture,the effects of associated cultivation with different crops on soil microbial diversity in rhizoshere and endophytic microbial community structure in root of tomatoes.Seven treatments are set up in the test,respectively:tomato×lettuce(A)、tomato×amaranth(B)、tomato×cabbage(C)、tomato×onion(D)、tomato×mint(E)、single cropping(F)and Blank(G),the research analysis using traditional and modern high-throughput sequencing technologies.The results are as follows::1 、 The results showed that the soil fertility in rhizosphere of tomatoes all could be improved by associated cultivation with lettuce,amaranth,onion and mint,respectively.In particularly,promoted nitrogen circulation in the rhizosphere soil of tomato plants,the activity of aminopeptidase in the rhizosphere soil of tomato under the associated cultivation treatments was 3.83,2.01,3.76,1.90 and 2.57 times of that under the single cropping(F)treatment,respectively.In additionthe growth and development of tomato plants could be obtained more phosphorus from soil by soil microbial biomass phosphorus be increased in rhizosphere under associated cultivation with different crops.Moreover,among five associated crops,lettuce and mint had no significant increase in β-glucosidase in tomato rhizosphere soil,but the activities of other soil enzymes and soil microbial biomass were significantly higher than that of monocropping(F)treatment,so soil fertility in rhizoshehre of tomatoes can be higher improved by associated with lettuce and mint.2 、 Compared with monoculture of tomato(CK),even though soil bacterial diversity and richness in rhizosphere of tomato associated cultivations were not significantly higher than those of CK,but the abundance of bacteria in rhizosphere of monoculture at phylum or genus levels was significantly changed by associated cultivations.Moreover,special bacteria at phylum or genus levels can be enriched in rhizosphere depending on the associated species.It indicated that soil bacterial community structure in rhizosphere of tomatoes can be altered by associated cultivations.3、Compared with CK,soil fungal community structure in rhizosphre of tomatoes at phylum or genus levels also can be altered by associated cultivations.However,the altered effect depends on the associated plant species.4 、 Compared with CK,even though the endophytic bacterial composition in roots of tomatoes at phylum level was not changed,but the proportion of endophytic bacterial abundance were altered by associated cultivations.In addition,the endophytic bacterial compositions in roots of tomatoes at genus levels were also altered byassociated cultivations.The associated crops,lettuce,onion and mint are better for improving the numbers of dominant endophytic bacteria in roots of tomatoes at genus level among five associated crops.5 、 Compared with CK,the composition of dominant endophytic fungi in roots of tomatoes was not only altered,but also their proportion of abundance at phylum level was changed by associated cultivations too.In addition,the composition and proportion of dominant endophytic fungi at genus level in roots of tomatoes were also altered by associated cultivations.In conclusion,soil fertility in rhizosphere of tomatoes can be improved by associated cultivations.Meanwhile,soil bacterial and fungal community structure in rhizosphere of tomatoes,and the endophytic bacterial and fungal community structure all can be altered by associated cultivations which compares to the CK.It indicates that the associated cultivation with tomatoes can be considered as a bio-control potential method in actual production.However,the effect of bio-control depends on the species of associated crops.Based on the characteristic of soil microbial communities in rhizosphere and endophytic microbial communities in roots of tomatoes,higher effect of bio-control among five associated crops(lettuce,amaranth,cabbage,onion and mint)with tomato were tomato*lettuce and tomato*mint associated treatments.