Effects of two plant growth-promoting Rhizobacteria on the germination and growth of pepper seedlings (Capsicum Annum) CV. Roxy: Wirkung von zwei wachstumsfordernden Rhizobakterien auf die keimung und das wachstum von pfeffersaaten (Capsicum Annum) CV. Roxy

Abstract

The effect of two plant growth-promoting rhizobacteria (PGPRs) on the germination and growth of pepper seedlings was investigated in a culture chamber. The two strains showed metabolic capacities related to their potential PGPR action. Two different patterns of inoculation were carried out. In the first, strains were inoculated when seeds were sown, and in the second when seedlings showed fully developed cotyledons. In both cases the following parameters were measured: aerial and root surface, aerial and root length and aerial and root weight. In the first pattern of inoculation no aerial parameters were modified, probably because the bacteria did not colonize the root. In the second pattern of inoculation, all parameters were significantly modified by Chryseobacterium balustinum, except root surface, which indicated that this bacterium was able to colonize the root. Serratia fonticola did not modify any parameter. In both inoculation patterns root length was reduced by both bacteria probably due to a hormonal effect. C. balustinum enhanced aerial surface, aerial length and also the dry aerial and root weight. This resulted in stronger and more robust plants with a higher adaptative capacity and a greater resistance against pathogens.

Keywords:

• PGPRs
• Colonization
• Pepper
• Inoculation
• Capsicum annum

Acknowledgements

We wish to thank Linda Hamalainen and Brian Crilly for their help in preparing the manuscript.