Soil microbial community structure in cucumber rhizosphere of different resistance cultivars to fusarium wilt

Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou, China.
FEMS Microbiology Ecology (Impact Factor: 3.57). 03/2010; 72(3):456-63. DOI: 10.1111/j.1574-6941.2010.00859.x
Source: PubMed


Cucumber fusarium wilt is a common soil-borne disease. We hypothesize that there is a relationship between the severity of disease and soil microbial ecology. In this work, culturable microbial populations, lipid fatty acid and community-level physiological profiles (CLPP) from rhizosphere soils of four different cucumber cultivars were investigated. Comparatively higher actinomycetes, mycorrhizal colonization and higher ratios of bacteria to fungi were found in the two resistant cultivars compared with the two susceptible cultivars. CLPP analysis showed that catabolic diversity indices were higher in the presence of two resistant cultivars. Phospholipid fatty acid (PLFA) profiles suggested that fungal (18:2omega6,9c) PLFA was enriched in the rhizosphere soils of the two susceptible cultivars, but some bacterial (16:0 and 15:0a) PLFAs were found in a lower relative abundance in these soils. The neutral lipid fatty acid 16:1omega5, which is an indicator of arbuscular mycorrhizal fungi, was enriched in the rhizosphere soils of the two resistant cultivars. All the three methods suggested that plant genotype had a significant impact on the soil microbial community composition and activity, and the differences in the rhizosphere microbial community may result in the differences in the resistance to fusarium wilt.

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Available from: Huaiying Yao, Oct 29, 2014
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    • "Rhizosphere bacteria are affected not only by the plant species but also by the cultivar (Germida and Siciliano 2001). Yao and Wu (2010) suggested that in cucumber cultivars, the level of resistance to Fusarium wilt had a significant effect on the soil microbial community and activity. These findings indicate that plants dramatically select their microflora (Hartmann et al. 2009). "
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    • "As an important indicator for the soil microbial ecology, the ratio of F/B has been used to indicate the shift of soil microbial community structure under environmental stress (Kaur et al., 2005; Yao and Wu, 2010). It has been reported that F/B ratio was positively correlated with soil fertility quality, but negatively with pollution level (Liu and Herbert, 2002; Zhang et al., 2012). "

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    • "Such suppressiveness is typically dependent upon the activity of resident beneficial or antagonistic microbes (Weller et al. 2002) with increasing microbial biomass and/or diversity (Larkin and Honeycutt 2006; Postma et al. 2008). Evenness of the rhizosphere microbiome is an important factor for soil suppression (Crowder et al. 2010; Yao and Wu 2010) ensuring that no individual microbial taxum is dominant. A diverse and even microbiome maximizes niche overlap between pathogens and other community members in the rhizosphere limiting empty niche space for potential invaders and new comers (Hillebrand et al. 2008). "
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