Bio-protective effect of a root-nodulating Rhizobium etli strain in common bean (Phaseolus vulgaris) against Meloidogyne incognita and Radopholus similis in an in vitro autotrophic tripartite culture system

Lieselot Van Der Veken,Pa Pa Win,Preeti Seeboruth,Rony Swennen,Dirk De Waele,Annemie Elsen,Ma Teodora N Cabasan

doi:10.1163/15685411-bja10066

Abstract

Summary The bio-protective effect of a root-nodulating strain (CNPAF 512) of the nitrogen-fixing rhizobium, Rhizobium etli, against both a sedentary (Meloidogyne incognita) and a migratory (Radopholus similis) endoparasitic nematode in common bean (Phaseolus vulgaris) was examined using an in vitro autotrophic tripartite culture system. Two in vitro assays were carried out with each of the nematode species. Each assay consisted of two treatments: the plants were either inoculated with the rhizobial strain or remained non-inoculated (control plants). To examine the effect of either pre- or simultaneous inoculation of the rhizobial strain on the reproduction of M. incognita and R. similis, one assay was carried out in which the nematodes were inoculated 3 weeks after rhizobial inoculation while another assay was carried out in which the nematodes were inoculated simultaneously with the rihizobial strain. Both pre-inoculation and simultaneous inoculation with R. etli CNPAF 512 significantly suppressed the reproduction of both M. incognita and R. similis.

Highlights

Summary – The bio-protective effect of a root-nodulating strain (CNPAF 512) of the nitrogen-fixing rhizobium, Rhizobium etli, against both a sedentary (Meloidogyne incognita) and a migratory (Radopholus similis) endoparasitic nematode in common bean (Phaseolus vulgaris) was examined using an in vitro autotrophic tripartite culture system
On the plants of the pre-inoculation assays infected with M. incognita, on average 43 and 27 nodules were counted in trials 1 and 2, respectively, while on the plants of the simultaneous inoculation assay with M. incognita, on average 87 nodules were counted (Fig. 2A)
The common bean plantlets developed a good root system, rhizobial inoculation resulted in functional nodules, and the infective developmental stages of M. incognita and R. similis infected the plantlets and developed and reproduced successfully inside the root systems

Summary

Introduction

Summary – The bio-protective effect of a root-nodulating strain (CNPAF 512) of the nitrogen-fixing rhizobium, Rhizobium etli, against both a sedentary (Meloidogyne incognita) and a migratory (Radopholus similis) endoparasitic nematode in common bean (Phaseolus vulgaris) was examined using an in vitro autotrophic tripartite culture system. To examine the effect of either pre- or simultaneous inoculation of the rhizobial strain on the reproduction of M. incognita and R. similis, one assay was carried out in which the nematodes were inoculated 3 weeks after rhizobial inoculation while another assay was carried out in which the nematodes were inoculated simultaneously with the rihizobial strain Both preinoculation and simultaneous inoculation with R. etli CNPAF 512 significantly suppressed the reproduction of both M. incognita and R. similis. The objective of our study was to evaluate the bioprotective effect of the root-nodulating strain R. etli CNPAF 512 against both a sedentary (M. incognita) and a migratory (R. similis) endoparasitic nematode in common bean. The experiment was carried out using an in vitro autotrophic tripartite culture system

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