RHIZOSPHERE MICROBIOTA PROFILE CHANGES WITH DIFFERENT GENETIC TYPES OF TOMATO SPECIES

Abstract

Use of improved seeds (hybrids, transgenic, etc.) in agriculture is a common practice in our days. Resulted plants could improve crop yield or to develop in less adequate geoclimatic conditions, responding those to challenges raised by global change. However, at now there are limited information on potential impact of such plants on soil properties and microbiota. Considering that microbiota are key mediators of soil functions and ecosystem processes it is important to fulfil such gaps. The objective of this study was to identify if different genetic varieties of Cherry tomato (Solanum lycopersicum), grown in same conditions, could influence root exudates (mainly carbohydrates) and rhizosphere microbiota profile. Randomized complete block rhizo-box experiment was performed with identic soil under similar growing conditions of genetic varieties Cherry tomatoes. PLFA and carbohydrates were analysed on GC-FID. In soil where tomatoes were grown the total PLFA amount was approximately two times higher compared with that detected from control (669.1 nmolg-1), which means that tomato root rhizosphere and exudates could influence soil microbiota. The average value of total PLFA for heirloom varieties was 1575.5 nmolg-1 while for hybrid varieties was 1269.4 nmolg-1. ANOVA test revealed significant differences between genetic type varieties of Cherry tomato (Solanum lycopersicum) rhizosphere microbiota community structure. Gram-positive, gram-negative bacteria and fungi abundance decreased in hybrid Cherry tomato varieties rhizosphere soils. Decreases in microbial and fungi community abundance may be related with decrease in carbohydrates content following with grown of different genetic hybrid varieties of Cherry tomato where some species exudates are reduced in essential carbohydrates content.

Keywords

• microbiota community structure, abundance, rhizosphere, hybrid species, root exudates