Comparative study of rhizobacterial communities in pepper greenhouses and examination of the effects of salt accumulation under different cropping systems.
This study compared rhizobacterial communities in pepper greenhouses under a paddy-upland (rice-pepper) rotational system (PURS) and a monoculture repeated cropping system (RCS) and examined adverse effects of high salinity on soil properties. The following soil properties were analyzed: electrical conductivity (EC), pH, concentration of four cations (Na, Ca, Mg, and K), total nitrogen, and organic matter content. Rhizobacterial communities were analyzed using culture-based and culture-independent (pyrosequencing) methods. In addition, all culturable bacteria isolated from each soil sample were tested for traits related to plant growth promotion. The EC of rhizospheric soils was 5.32-5.54 dS/m for the RCS and 2.05-2.19 dS/m for the PURS. The culture-based method indicated that the bacterial communities and bacterial characteristics were significantly more diverse in the PURS soil than in the RCS soil. The pyrosequencing data also indicated that the richness and diversity of bacterial communities were greater in the PURS soil. Proteobacteria was the most abundant phylum in soil samples under both cropping systems. However, Firmicutes and Gemmatimonadetes were more prevalent in the RCS soil, while the PURS soil contained a greater number of Chloroflexi. Spearman's correlation coefficients showed that soil EC was significantly positively correlated with the abundance of Firmicutes and Gemmatimonadetes and negatively correlated with the abundance of Acidobacteria, Chloroflexi, and Deltaproteobacteria. This is the first study on the rhizobacterial communities in pepper greenhouses under two different cropping systems using both culture- and pyrosequencing-based methods.
School of Life Science, BK21 Plus KNU Creative BioResearch Group, Institute for Microorganisms, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea.
Mi-Seon
MS
Hahm
School of Life Science, BK21 Plus KNU Creative BioResearch Group, Institute for Microorganisms, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea.
Jin-Soo
JS
Son
Department of Horticulture, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea.
Byung-Soo
BS
Kim
School of Life Science, BK21 Plus KNU Creative BioResearch Group, Institute for Microorganisms, Kyungpook National University, 80 Daehakro, Bukgu, Daegu, 41566, Korea. ghimsa@knu.ac.kr.
Sa-Youl
SY
Ghim
D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000069599:Crop Production; D004553:Electric Conductivity; D020560:Proteobacteria / Q000302:isolation & purification; D058441:Rhizosphere; D054712:Salinity; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
D012987:Soil
16S rRNA; Cropping system; Pyrosequencing; Rhizobacterial communities; Soil bacterial diversity