Evolution of wild and feral vines from the Ega river gallery forest (Basque country and Navarra, Spain) from 1995 to 2015

Abstract

Aims: The present paper is focused on wild and feral grapevines from the Ega River gallery forest (Alder grove), one of the most important tributaries of the Ebro River. Since this area was preliminary prospected in 1995, it was our intention to assess the evolution of the ecosystem during this time. Methods and results: Ampelographic description of wild grapevines shows that all male plants had flowers with fully developed stamens and no gynoecium. No hermaphrodite individuals were detected. No virus infection and symptoms caused by Phylloxera on roots were detected. The Erineum strain of Colomerus vitis constitutes the main phytophagous arthropod. Damages caused by powdery and downy mildew were not lethal for the vines. Around 73% of the wild grapevine individuals found in 1995 had disappeared due to human impacts. The number of rootstocks and producer hybrids (French hybrids) had increased in this period by about 30%. Microvinification of wild berries yielded a wine with very high color intensity and total polyphenol index with a low pH. Conclusion: The wild grapevine population described has suffered a dramatic regression in the 20-year period between prospections, together with a significant increase of feral accessions thus endangering the endurance of the ecosystem and remaining wild grapevine. Significance and impact of the study : Wild grapevines are a valuable genetic resource for the genetic improvement of cultivated vines. However, our study shows that human impacts and increasing pressure of feral accessions are threatening wild grapevine populations.

Keywords

• Alder grove
• endangered taxon
• loss of biodiversity
• sanitary status
• Vitis vinifera subsp. sylvestris