Soil properties and olive cultivar determine the structure and diversity of plant-parasitic nematode communities infesting olive orchards soils in southern Spain

PLoS One. 2015 Jan 27;10(1):e0116890. doi: 10.1371/journal.pone.0116890. eCollection 2015.

Abstract

This work has studied for the first time the structure and diversity of plant-parasitic nematodes (PPNs) infesting olive orchard soils in a wide-region in Spain that included 92 locations. It aims at determining which agronomical or environmental factors associated to the olive orchards are the main drivers of the PPNs community structure and diversity. Classical morphological and morphometric identification methods were used to determine the frequency and densities of PPNs. Thirteen families, 34 genera and 77 species of PPNs were identified. The highest diversity was found in Helicotylenchus genus, with six species previously reported in Spain and with H. oleae being a first report. Neodolichorhynchus microphasmis and Diptenchus sp., Diphtherophora sp., and Discotylenchus sp., usually considered fungal feeders, were also reported for the first time associated to olive rhizosphere. PPNs abundance ranged from 66 to 16,288 individuals/500-cm3 of soil with Helicotylenchus digonicus being the most prevalent species, followed by Filenchus sp., Merlinius brevidens and Xiphinema pachtaicum. Nematode abundance and diversity indexes were influenced by olive cultivar, and orchard and soil management practices; while olive variety and soil texture were the main factors driving PPN community composition. Soil physicochemical properties and climatic characteristics most strongly associated to the PPN community composition included pH, sand content and exchangeable K, and maximum and minimum average temperature of the sampled locations. Our data suggests that there is a high diversity of PPNs associated to olive in Southern Spain that can exert different damage to olive roots depending on the olive variety and their abundance. Further analysis to determine the resistance levels of most common olive varieties to the prevalent PPNs in Spain will help to choose the most appropriate ones for the establishment of new plantations. This choice will take into consideration the specific soils and environments where those olive varieties will be established.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Nematoda / anatomy & histology
  • Nematoda / isolation & purification*
  • Olea / parasitology*
  • Plant Diseases / parasitology*
  • Soil / chemistry*
  • Soil / parasitology

Substances

  • Soil

Grants and funding

Financial support was received by Projects AGL2008-00344/AGR from ‘Ministerio de Ciencia e Innovación’, Project AGL-2012-37521 from ‘Ministerio de Economía y Competitividad’ of Spain and Projects P10-AGR-5908 and P12-AGR-1486 from ‘Consejería de Economía, Innovación y Ciencia’ of Junta de Andalucía, and FEDER financial support from the European Union is gratefully acknowledged. The grant 219262 ArimNET_ERANET FP7 2012-2015 Project PESTOLIVE ‘Contribution of olive history for the management of soilborne parasites in the Mediterranean basin’ from Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), and the ‘Internacional del Aceite de Oliva Español-Citoliva’ also provided partial financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.