Soil microbial communities in agroecosystems and natural habitats contributing to resistance and resilience of the soil environment

• Název práce v češtině: Půdní mikrobiální společenstva přispívající k rezistenci a resilienci půdního prostředí v agroekosystémech a na přírodních stanovištích
• Název v anglickém jazyce: Soil microbial communities in agroecosystems and natural habitats contributing to resistance and resilience of the soil environment
• Klíčová slova: microbial community, Actinobacteria, common potato scab, soil organic matter
• Klíčová slova anglicky: microbial community, Actinobacteria, common potato scab, soil organic matter
• Akademický rok vypsání: 2012/2013
• Typ práce: disertační práce
• Jazyk práce: angličtina
• Ústav: Katedra genetiky a mikrobiologie (31-140)
• Vedoucí / školitel: Ing. Jan Kopecký, Ph.D.
• Řešitel: skrytý - zadáno vedoucím/školitelem
• Datum přihlášení: 27.10.2012
• Datum zadání: 27.10.2012
• Datum a čas obhajoby: 25.06.2020 15:00
• Datum odevzdání elektronické podoby: 30.09.2019
• Datum proběhlé obhajoby: 25.06.2020
• Oponenti: prof. doc. Ing. Kateřina Demnerová, CSc.
• Konzultanti: doc. RNDr. Markéta Marečková, prom. biol., Ph.D.

Předběžná náplň práce v anglickém jazyce

Plant and microbial community composition in connection with soil chemistry determine soil nutrient cycling. The microbial community depends on inputs of plant litter and nutrients available in the soil environment, and develops in response to the availability of resources. At the same time, the microbial community also shapes the soil environment by the way and rate of processing the organic matter inputs. A structured soil rich in organic matter is expected to provide number of niches and harbor a diverse, stable microbial community. A diverse community is resistant to external disruptions such as variations of temperature and precipitation, and also prevents spreading soil-borne pathogens. Agricultural soils often suffer from insufficient plant litter inputs, or inputs of homogeneous material from a monoculture, resulting in decrease of soil organic matter content, which is further promoted by tillage. Consequently, microbial communities in agroecosystems inhabit less structured environment and lose their diversity.
The relationship between soil organic matter content, and resistance of a diverse soil microbial community will be explored using a model soil-born disease, common potato scab. The disease drastically affects tuber quality due to superficial and pitted lesions that form around the site of infection. Microorganisms responsible for the infection are plant-pathogenic Streptomyces spp. The pathogens are neither host nor tissue specific suggesting that their pathogenicity strategies target components of cells that are conserved across plant families and expressed in multiple plant tissues. The disease incidence was mainly studied in relationship to plant cultivars and soil physico-chemical characteristics. Soil and plant tissue contents of several nutrients were related to the disease severity and the effect of soil moisture on the disease suppression was also observed. However, these correlations differed significantly between regions and sites. Consequently, the effects of scab control approaches, which include the development of resistant cultivars, specific fertilization, increasing soil moisture, and chemical treatments strongly depend on local conditions and potato scab remains one of the top diseases of potato.
The general goals of the thesis will be (i) to explore the mutual interaction between soil organic matter quality, carbon sources, and microbial community composition in manipulated agricultural soils; and (ii) to show the interaction of the soil environment factors with potato variety in shaping the community inhabiting potato rhizosphere. The project also aims to develop and test novel preventive provisions to control the common potato scab occurrence based on 1) soil supplements of macro and microelements to support optimal plant growth and 2) soil supplements by selected forms of organic matter to promote restoration of a diverse community suppressing development of pathogenic bacteria.