Abstract

SANCHEZ-BAUTISTA, Alma et al. Root endophyte bacteria in drought-tolerant and drought-susceptible maize lines. Rev. mex. fitopatol [online]. 2018, vol.36, n.1, pp.35-55. ISSN 2007-8080.  https://doi.org/10.18781/r.mex.fit.1710-3.

Maize (Zea mays) ranks second as food in the world and drought limits its productivity. Plants harbor endophytic bacteria that influence health and drought tolerance. The goal of this research was to estimate the density and diversity of cultivable endophyte bacteria from the root system of seven homozygous maize drought-tolerant and seven drought-susceptible lines in three locations of Mexico during three crop cycles. The density and diversity of bacterial populations was assessed by direct counting on plates and identified by PCR. The results identified three groups of endophytic bacteria: 1) highly frequent (Bacillus subtilis, Bacillus megaterium y Pseudomonas geniculata), 2) frequent (Bacillus firmus, Pseudomonas hibiscola y Sinorhizobium meliloti) y 3) low frequency (Acinetobacter soli, Stenotrophomonas maltophila y Burkholderia gladioli. The analysis of variance (ANOVA) showed significant differences (p≤0.05) in density (Log10 CFU g-1 root) of population by location, crop cycle, days after sowing and maize lines. The density of Bacillus subtilis, Pseudomonas hibiscola at El Batán and Bacillus megaterium, Sinorhizobium meliloti in Tlaltizapán, were significantly higher in drought-tolerant maize lines compared to drought-susceptible lines.

Keywords : Zea mays; endophytic bacteria; bacterial diversity; 16S rADN.

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