Plant and Soil

, Volume 253, Issue 2, pp 381–390 | Cite as

Bacterial endophytes in processing carrots (Daucus carota L. var. sativus): their localization, population density, biodiversity and their effects on plant growth

  • Monique A. Surette
  • Antony V. Sturz
  • Rajasekaran R. Lada
  • Jerzy Nowak


A survey of endophytic bacteria colonizing roots of processing carrots (Daucus carota) was performed with two high-yielding cultivars (Carochoice, Red Core Chantenay) grown at two locations (Canning, Great Village) in Nova Scotia. Most bacterial endophyte colony-forming units (CFU) were recovered from the carrot crown tissues (96%) compared to the periderm and metaxylem tissues of carrot storage tissues irrespective of the cultivars and field locations. Greater population densities of endophytic bacteria were recovered from the crowns of Red Core Chantenay (5.75 × 105 CFU/g FW in Great Village; 3.0 × 105 CFU/g FW in Canning) cultivar, which accounted for 78% of all of CFU recovered compared to cv. Carochoice. Independent of the cultivars, more endophytes were recovered from the carrots produced in Great Village compared to the ones grown in Canning (62 vs. 38%, respectively). Of 360 isolates examined, 28 bacterial genera were identified, of which, Pseudomonas, Staphylococcus, and Agrobacterium were the most common (31, 7 and 7%, respectively). Diversity indices showed no significant differences between the two locations. A bioassay using selected strains of bacteria was performed on 4 week-old carrot (cv. Bergen) and potato (Solanum tuberosum cv. Atlantic) plantlets. In carrots, 83% of the bacterial strains tested were found to be plant growth promoting, 10% remained plant growth neutral and 7% inhibited plant growth. In contrast, in the potato bioassay 38% remained growth neutral, 33% promoted and 29% inhibited plant growth.

allelopathy bioassay Daucus carota endophyte plant growth promoting 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Anderson A J and Guerra D 1985 Responses of bean to root colonization with Pseudomonas putida in a hydroponic system. Phytopathology 75, 992–995.Google Scholar
  2. Atlas R M, Horowitz A, Krichevsky M and Bej A K 1991 Response of microbial population to environmental disturbance. Microb. Ecol. 22, 249–256Google Scholar
  3. Benhamou N, Kloepper J W, Quadt-Hallman A and Tuzun S 1996 Induction of defence-related ultrastructural modifications in pea root tissues inoculated with endophytic bacteria. Plant Physiol. 112, 919–929.Google Scholar
  4. Bensalim S, Nowak J and Asiedu S K 1998 A plant growth promoting rhizobacterium and temperature effects on performance of 18 clones of potato. Am. J. Potato Res. 75, 145–152.Google Scholar
  5. Chanway C F 1996 Endophytes: they're not just fungi! Can. J. Bot. 74, 321–322.Google Scholar
  6. Chen C, Bauske E M, Musson G, Rodríguez-Kábana R and Kloeppler J W 1995 Biological control of Fusarium wilt on cotton by use of endophytic bacteria. Biol. Control 5, 83–91.Google Scholar
  7. Chen W, Hoitink H A J and Madden L V 1988 Microbial activity and biomass in container media for predicting suppressiveness to dampening-off caused by Pythium ultimum. Phytopathology 78, 1447–1450.Google Scholar
  8. Clark F E 1965 Agar-plate method for total microbial count. Chapter 99. In Methods of Soil Analysis, Part 2. Chemical and Microbiological Properties. Eds. CA Black, DD Evans, JL White and LE Ensiminger. pp. 1460–1466. Am. Soc. Agronomy Inc. Wisconsin, USA.Google Scholar
  9. Conn K L, Nowak J and Lazarovits G 1997 A gnotobiotic bioassay for studying interactions between potatoes and plant growthpromoting rhizobacteria. Can. J. Microbiol. 43: 801–808.Google Scholar
  10. Creus C M, Sueldo R J and Barassi C A 1998 Water relations in Azospirillum-inoculated wheat seedlings under osmotic stress. Can. J. Bot. 76, 238–244.Google Scholar
  11. Dalal R C, Henderson P A and Glasby J M 1991 Organic matter and microbial biomass in a vertisol after 20 yr of zero tillage. Soil Biol. Biochem. 23, 435–441.Google Scholar
  12. de Freitas J R and Germida J J 1990 Plant growth promoting rhizobacteria for winter wheat. Can. J. Microbiol. 36, 265–272.Google Scholar
  13. Fisher P J, Petrini O and Lappin Scott H M 1992 The distribution of some fungal and bacterial endophytes in maize (Zea mays L.). New Phytol. 122, 299–305.Google Scholar
  14. Frommel M I, Nowak J and Lazarovits G 1991 Growth enhancement and developmental modifications of in vitro grown potato (Solanum tuberosum ssp. tuberosum) as affected by a non-fluorescent Pseudomonas sp. Plant Physiol. 96, 926–938.Google Scholar
  15. Germida J J, Siciliano S D, de Freitas R and Seib A M 1998 Diversity of root-associated bacteria associated with field-grown canola (Brassica napus L.) and wheat (Triticum aestivum L.). FEMS Microbiol. Ecol. 26, 43–50.Google Scholar
  16. Hallmann J, Qualt-Hallmann A, Mahaffee W F and Kloepper J W 1997 Bacterial endophytes in agricultural crops. Can J. Microbiol. 43, 895–914.Google Scholar
  17. Hallmann J, Rodríguez-Kábana R and Kloepper J W 1999 Chitinmediated changes in bacterial communities of the soil, rhizosphere and within roots of cotton in relation to nematode control. Soil Biol. Biochem. 31, 551–560.Google Scholar
  18. Harris P A, Schomberg H H, Banks P A and Giddens J 1995 Burning, tillage and herbicide effects on the soil microflora in a wheat-soybean double-crop system. Soil Biol. Biochem. 27, 153–156.Google Scholar
  19. Hollis J P 1951 Bacteria in healthy potato tissue. Phytopathology 41, 350–366.Google Scholar
  20. Hurek T, Reinhold-Hurek B, Van Montagu M and Kellenberger E 1994 Root colonization and systematic spreading of Azoarcus sp. Strain BH72 in grasses. J. Bacteriol. 176, 1913–1923.Google Scholar
  21. Jacobs M J, Bugbee W M and Gabrielson D A 1985 Enumeration, location, and characterization of endophytic bacteria within sugar beet roots. Can. J. Bot. 63, 1262–1265.Google Scholar
  22. Kennedy A C and Smith K L 1995 Soil microbial diversity and the sustainability of agricultural soils. Plant Soil 170, 75–86.Google Scholar
  23. Kloepper J W, Hume D J, Scher F M, Singleton C, Tipping B, Laliberté M, Frauley K, Kutchaw T, Simonson C, Lifshitz R, Zaleska I and Lee L 1988 Plant growth-promoting rhizobacteria on canola (rapeseed). Plant Dis. 72, 42–46.Google Scholar
  24. Koch A L 1994 Growth measurement. In Methods for General and Molecular Bacteriology. Ed. P Gerhardt. pp. 248–277. American Society of Microbiology, Washington, DC, USAGoogle Scholar
  25. Lalande R, Bissonette N, Coutlée D and Antoun H 1989 Identi-fication of rhizobacteria from maize and determination of their plant-growth promoting potential. Plant Soil 115, 7–11.Google Scholar
  26. Lamb T G, Tonkyn D W and Kluepfel D A 1996 Movement of Pseudomonas aureofaciens from the rhizosphere to aerial plant tissue. Can. J. Microbiol. 42, 1112–1120.Google Scholar
  27. Lazarovits G and Nowak J 1997 Rhizobacteria for improvement of plant growth and establishment. HortScience 32, 188–192.Google Scholar
  28. Liu L, Kloepper J W and Tuzun S 1995 Induction of systemic resistance in cucumber by plant growth-promoting rhizobacteria: duration of protection and effect of host resistance on protection and root colonization. Phytopathology 85, 1064–1068.Google Scholar
  29. Lynch J M and Panting L M 1980 Cultivation and the soil biomass. Soil Biol. Biochem. 12, 29–33.Google Scholar
  30. McInroy J A and Kloepper J W. 1995 Population dynamics of endophytic bacteria in field-grown sweet corn and cotton. Can. J. Microbial. 41, 895–901.Google Scholar
  31. Merriman P R, Price R D, Kollmorgen J F, Piggott T and Ridge E H 1974 Effect of seed inoculation with Bacillus subtilis and Steptomyces griseus on the growth of cereals and carrots. Aust. J. Agric. Res. 25, 219–226.Google Scholar
  32. MIDI Inc. 1999 MIS whole cell fatty acid analysis by gas chromatography. Ed. R Paisley. MIDI, Inc., Newark, DE, USA.Google Scholar
  33. Misaghi I J and Donndelinger C R 1990 Endophytic bacteria in symptom-free cotton plants. Phytopathology 80, 808–811.Google Scholar
  34. Moorman T B and Dowler C C 1991 Herbicide and rotation effects on soil and rhizosphere microorganisms and crop yields. Agric. Ecosyst. Environ. 35, 311–325.Google Scholar
  35. Mundt J O and Hinkle N F 1976 Bacteria within ovules and seeds. Appl. Environ. Microbiol. 32, 694–698.Google Scholar
  36. Murashige T and Skoog F 1962 A revised medium for rapid growth and bio assays with tobacco tissue cultures. Physiol. Plant. 15, 473–497.Google Scholar
  37. Nowak J 1998 Benefits of in vitro ‘biotization’ of plant tissue cultures with microbial inoculants. In Vitro Cell. Dev. Biol. Plant. 34, 122–130.Google Scholar
  38. Nowak J, Asiedu S K, Lazarovits G, Pillay V, Stewart A, Smith C, and Liu Z 1995 Enhancement of in vitro growth and transplant stress tolerance of potato and vegetable plantlets co-cultured with a plant growth promoting pseudomonad bacterium. In Ecophysiology and Photosynthetic In Vitro Cultures. Eds. F Carre, P Chagvardieff. pp. 173–180. C.E.A. Cadarache. Aix-en-Provence, France.Google Scholar
  39. Patriquin D G and Döbereiner J 1978 Lightmicroscopy observations of tetrazolium-reducing bacteria in the endorhizosphere of maize and other grasses in Brazil. Can. J. Microbiol. 24, 734–742.Google Scholar
  40. Pillay V K and Nowak J 1997 Inoculum density, temperature, and genotype effects on in vitro growth promotion and epiphytic and endophytic colonization of tomato (Lycopersicon esculentum L.) seedlings inoculated with a pseudomonad bacterium. Can. J. Microbiol. 43, 354–361.Google Scholar
  41. Quadt-Hallman A, Hallman J and Kloepper J W 1997a Bacterial endophytes in cotton: location and interaction with other plant associated bacteria. Can. J. Microbiol. 43, 254–259.Google Scholar
  42. Quadt-Hallman A, Benhamou N and Kloepper JW 1997b Bacterial endophytes in cotton: mechanisms of entering the plant. Can. J. Microbiol. 43, 577–582.Google Scholar
  43. Samish Z, Etinger-Tulczynska R and Bick M 1961 Microflora within healthy tomatoes. Appl. Microbiol. 9, 20–25.Google Scholar
  44. SAS Institute Inc. 1989 SAS/STAT User's Guide, version 6, 4th edition. SAS Institute, Cary, NC, USA.Google Scholar
  45. Sharma V K and Nowak J 1998 Enhancement of verticulum wilt resistance in tomato transplants by in vitro co-culture of seedlings with a plant growth promoting rhizobacterium (Pseudomonas sp. strain PsJN). Can. J. Microbiol. 44, 528–536.Google Scholar
  46. Shishido M, Breuil C and Chanway C P 1999 Endophytic colonization of spruce by plant growth-promoting rhizobacteria. FEMS Microbiol. Ecol. 29, 191–196.Google Scholar
  47. Sitnikov DM, Schineller J B and Baldwin T O 1995 Transcriptional regulation of bioluminescence genes from Vibrio fisheri. Mol. Microbiol. 17, 801–812.Google Scholar
  48. Sturz A V and Christie B R 1996 Endophytic bacteria of red clover as causal agents of allelopathic clover-maize syndromes. Soil Biol. Biochem. 28, 583–588.Google Scholar
  49. Sturz A V and Matheson B G 1996 Populations of endophytic bacteria which influence host-resistance to Erwinia-induced bacterial soft rot in potato tubers. Plant Soil. 184, 265–271.Google Scholar
  50. Sturz A V, Carter M R and Johnston H W 1997 A review of plant disease, pathogen interactions and microbial antagonism under conservation tillage in temperate humid agriculture. Soil Till. Res. 41, 169–189.Google Scholar
  51. Sturz A V, Christie B R and Matheson B G 1998 Associations of bacterial endophyte populations from red clover and potato crops with potential for beneficial allelopathy. Can. J. Microbiol. 44, 162–167.Google Scholar
  52. Sturz A V, Christie B R, Matheson B G, Arsenault W J and Buchanan N 1999 Endophytic bacterial communities in the periderm of potato tubers and their potential to improve resistance to soil-borne plant pathogens. Plant Pathol. 48, 360–370.Google Scholar
  53. Sturz A V, Christie B R, and Nowak J 2000 Bacterial endophytes: potential role in developing sustainable systems of crop production. CRC Crit. Rev. Plant Sci. 19, 1–30.Google Scholar
  54. Suslow T V and Schroth M N 1982 Rhizobacteria of sugar beets: effects of seed application and root colonization on yield. Phytopathology 72, 199–206.Google Scholar
  55. Tortora G F, Funke B R and Case C L 2001 Microbiology: an Introduction. Benjamin Cummings. San Francisco, CA, USA. 97 pp.Google Scholar
  56. Wardle D A, Yeates G W, Nicholson K S, Bonner K I and Watson R N 1999 Response of soil microbial biomass dynamics, activity and plant litter decomposition to agricultural intensification over a seven-year period. Soil Biol. Biochem. 31, 1707–1720.Google Scholar

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Monique A. Surette
    • 1
  • Antony V. Sturz
    • 2
  • Rajasekaran R. Lada
    • 1
    • 3
  • Jerzy Nowak
    • 1
    • 4
  1. 1.Department of Plant and Animal SciencesCox Institute, Nova Scotia Agricultural CollegeTruroCanada
  2. 2.Department of Agriculture and ForestryPrince Edward IslandCharlottetownCanada
  3. 3.Asian Vegetable Research and Development Centre (AVRDC)Shanhua, TainanTaiwan
  4. 4.Virginia Polytechnic Institute and State UniversityBlacksburgUSA

Personalised recommendations