Abstract

SERRET-LOPEZ, María; ESPINOSA-VICTORIA, David; GOMEZ-RODRIGUEZ, Olga  and  DELGADILLO-MARTINEZ, Julián. Tolerance of strawberry (Fragaria × ananassa Duch.) plants pre-mycorrhized with Rhizophagus intraradices and inoculated with PGPR’s to Phytophthora capsici. Agrociencia [online]. 2016, vol.50, n.8, pp.1107-1121. ISSN 2521-9766.

The tolerance to wilting caused by the oomycete Phytophthora capsici in strawberry (Fragaria×ananassa Duch.) var. Festival was evaluated by premycorrhization with the fungus Rhizophagus intraradices and inoculation with a consortium of PGPR’s (Plant Growth Promoting Rhizobacteria) composed of Pseudomonas tolassi, Bacillus pumilus, and Paenibacillus sp. The inoculation of biocontrolling microorganisms was carried out separately and in combination 8 d after transplanting. The inoculation of P. capsici was carried out 45 d after applying biocontrollers. The experimental design was completely randomized, data were analyzed by ANOVA and the averages of treatments were compared using Tukey’s test (p≤0.05). In a previous antagonism in vitro experiment, P. tolassi and B. pumillus were found to inhibit oomycete growth by 54 %, while Paenibacillus sp. did the same by 43 %. The production of metabolites by rhizobacteria that disseminate and inhibit the growth of the oomycete is suggested. The severity of the disease in plants treated with P. capsici was 63 %, but it was lower (23 %) in plants inoculated with PGPR’s+R. intraradices. Plants inoculated with PGPR’s+R. intraradices showed the highest values for foliar area (239.95 cm2), dry biomass of aerial section (6.24 g), root volume (2.1 mL) and number of stolons (5). Plants previously treated with PGPR’s and R. intraradices and then inoculated with P. capsici, increased foliar area, aerial biomass, and root volume by 44, 7, and 58 %, respectively, in comparison to plants inoculated only with the oocmycete. According to the analysis of results, bio-controlling microorganisms promote the tolerance of strawberry plants to wilting induced by P. capsici.

Keywords : Phytophthora capsici; Fragaria×ananassa Duch.; Rhizophagus intraradices; Pseudomonas tolassi; Bacillus pumilus; Paenibacillus sp.; biocontrol; PGPR’s.

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