Plant-parasite coevolution: A weak signature of local adaptation between Peruvian Globodera pallida populations and wild potatoes.

Camille Gautier,Lionel Renault,Sylvain Fournet,Josselin Montarry,Eric Nguema-Ona,Christophe Piriou,Jean-Claude Yvin,Eric Grenier

doi:10.1002/ece3.6248

Abstract

Plant–parasite coevolution has generated much interest and studies to understand and manage diseases in agriculture. Such a reciprocal evolutionary process could lead to a pattern of local adaptation between plants and parasites. Based on the phylogeography of each partner, the present study tested the hypothesis of local adaptation between the potato cyst nematode Globodera pallida and wild potatoes in Peru. The measured fitness trait was the hatching of cysts which is induced by host root exudates. Using a cross‐hatching assay between 13 populations of G. pallida and root exudates from 12 wild potatoes, our results did not show a strong pattern of local adaptation of the parasite but the sympatric combinations induced better hatching of cysts than allopatric combinations, and there was a negative relationship between the hatching percentage and the geographical distance between nematode populations and wild potatoes. Moreover, a strong effect of the geographic origin of root exudates was found, with root exudates from south of Peru inducing better hatching than root exudates from north of Peru. These results could be useful to develop new biocontrol products or potato cultivars to limit damages caused by G. pallida.

Highlights

Plants are constantly interacting with many organisms in their environment, and these interactions may be directly and/or indirectly beneficial or harmful for the plant (Bais, Weir, Perry, Gilroy, & Vivanco, 2006)
To explore the level of dependence between populations of G. pallida and root exudates from wild potato species, the present study addressed one main question: Is there a detectable pattern of local adaptation for the hatching trait between G. pallida populations and wild potatoes coming from Peru?
A Pearson's product–moment correlation test was performed to study the correlation between the geographic distance, between nematode populations and wild potatoes, and the hatching percentage

Summary

| INTRODUCTION

Plants are constantly interacting with many organisms in their environment, and these interactions may be directly and/or indirectly beneficial or harmful for the plant (Bais, Weir, Perry, Gilroy, & Vivanco, 2006). Our case study involved the cyst nematode Globodera pallida, one of the major pest of potato crop worldwide (Oerke, Dehne, Schönbeck, & Weber, 2012; Turner & Evans, 1998) and listed in the EU Plant Health Directive 2000/29/EC regulated by the European PCN Directive (2007/33/EC) This nematode originated from the Andean region of South-America, the origin of its wild host potatoes and other Solanum species (Evans & Stone, 1977; Hijmans & Spooner, 2001). To explore the level of dependence between populations of G. pallida and root exudates from wild potato species, the present study addressed one main question: Is there a detectable pattern of local adaptation for the hatching trait between G. pallida populations and wild potatoes coming from Peru?

| MATERIALS AND METHODS

Findings

| DISCUSSION