Molecular identification of Meloidogyne spp. Infecting beans (Phaseolus vulgaris) in Argentina.

GALLARDO CLAUDIA; CAP GUILLERMO; ACHINELLY , MARÍA F.,

Arequipa

Congreso; 51 th ONTA Annual meeting.; 2018

ONTA

Argentina is the fifth largest producer of beans (Phaseolus vulgaris) on the American continent, with 99% of national production concentrated in the Northwest region. Root-knot nematodes (Meloidogyne spp.) have been reported as one of the most important pathogens infecting beans in many parts of the world, not only because of its direct damage, but also for creating access for numerous bacteria and fungi that affect its performance. Although there have been multiple observed associations between beans and root-knot nematodes (Meloidogyne spp.) in Argentina, many of these reports have not been well analyzed or documented, and very little is known about the species of root-knot nematodes involved in such associations. The objective of this work was to use a molecular approach to identify Meloidogyne spp. found infecting white beans in the Jujuy province, Argentina. In 2016, soil samples were collected from the rhizosphere of white bean var. Alubia, in the locality of Río Blanco, department Palpalá (24 °13 ´40´ S/ 65 ° 14´40.70 ´´, O). Seedlings of Impatiens sp. were transplanted into the infested soil samples and maintained in a greenhouse for 60 days. Configuration of the perineal patterns, morphometrics of selected characters of nematode females including body, stylet and tail length were consistent with those reported in the original description of M. arenaria. For the molecular analysis, nematode females were extracted from the roots and placed in 96% ethanol for further use. DNA was extracted from individual females and mitochondrial DNA (mtDNA) was amplified using the following primer sets: MORF (5? -ATCGGGGTTTAATAATGG G -3?) and MTHIS (5? -AAATTC AATTGAAATTAATAG C- 3?); TRNAH (5? -TGA ATT TTT TAT TGT GAT TAA-3?) and MHR106 (5? - ATT TCC TAA AGA CTT TTC TTA GT-3?). A fragment of approximately 740 bp and 550 bp was obtained with each of the above primer sets, respectively. To further confirm the nematode species identification, we used the M. arenaria species-specific SCAR primer set Far (5?- TCGGCGATAGAGGTAAATGAC-3?), Rar (5?-TCGGCGATAGACACTACAACT-3?). This primer set yielded a fragment of approximately 430 bp, which is identical to that previously reported for M. arenaria. DNA sequencing is still in progress. To our knowledge this report constituted the first molecular identification of M. arenaria found infecting beans in Argentina.