Agronomy (Sep 2021)

Growth Promotion of Rapeseed (<i>Brassica napus</i> L.) and Blackleg Disease (<i>Leptosphaeria maculans</i>) Suppression Mediated by Endophytic Bacteria

  • Nikola Lipková,
  • Juraj Medo,
  • Renata Artimová,
  • Jana Maková,
  • Jana Petrová,
  • Soňa Javoreková,
  • Jaroslav Michalko

DOI
https://doi.org/10.3390/agronomy11101966
Journal volume & issue
Vol. 11, no. 10
p. 1966

Abstract

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Rapeseed is an important oil crop strongly dependent on high agrochemical inputs. Some pathogens, including Leptosphaeria maculans, cause blackleg disease and can drastically decrease yields. Microbial inoculants seem to be a promising solution to these problems. However, a selection of potent bacterial strains able to improve growth and/or suppress disease is needed. Endophytic bacteria (n = 38) isolated from rapeseed plants with exceptionally good growth were screened for plant growth promoting (PGP) traits and L. maculans antifungal activity. A majority of isolates (35) showed the ability to produce siderophores, 17 isolates solubilized phosphate, and 28 isolates inhibited the growth of L. maculans. The six most promising isolates belonging to Bacillus genera were characterized in detail and compared to two previously published PGP strains. Plant growth measured as total weight and root length of rapeseed seedlings was stimulated by all isolates in comparison to control. The best isolate, 1L6, preliminary identified as Bacillus pumilus showed the highest phosphate solubilization, IAA and HCN production, and growth promotion of plants. Isolates with high antifungal activity in screening showed good potential to suppress disease on plants, with 87% reduction of lesions caused by L. maculans. These strains are good candidates to be explored under field use either solely or in combination.

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