terclim by ICS banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2023 9 Stem growth disorder and xylem anatomy modifications during esca pathogenesis in grapevines

Stem growth disorder and xylem anatomy modifications during esca pathogenesis in grapevines

Abstract

Context and purpose of the study – Esca is a grapevine vascular disease with detrimental consequences on vineyard yield and longevity. Recently, esca leaf symptom development has been shown to result in the occlusion of xylem vessels by tyloses in leaves and stems, leading to hydraulic failure. However, little is known regarding the response of xylem anatomy and stem growth to esca in different varieties . Here we studied the impact of esca leaf symptom development on grapevine physiology, stem growth, and xylem anatomy in two widespread cultivars, Cabernet sauvignon and Sauvignon blanc.

Material and methods – To study esca under controlled conditions and since pathogen inoculations are not able to reproduce esca leaf symptoms, we used an original experimental design made of infected plants uprooted from two vineyards in France and transplanted into pots. Two grape varieties were compared in this experiment: 9 Sauvignon blanc grafted on Fercal  and 10 Cabernet Sauvignon grafted on 101-14MGt, all 19-20 years old. Multiple traits were monitored during 3 months in the greenhouse: the plant-water relation at leaf and whole-plant scales (by monitoring whole-plant and leaf gas exchange, predawn and midday water potentials), stem growth (using dendrometer measurements), xylem anatomy (optical microscopy of stem and midrib cross sections) and esca symptom expression during the season.

Results – The onset of leaf symptom expression led to a decrease in gas exchange at whole plant and leaf scales in both Cabernet sauvignon and Sauvignon blanc. However, plants were able to produce new secondary green leaves after symptom development. Esca significantly impacted the growth of symptomatic stems, by altering the shrinkage phase in both grape varieties. A thorough study of the xylem anatomy identifying individual vessel area, position within the stem cross-section, and level of occlusion demonstrated that the percentage of theoretical loss of conductivity (PLCth) due to tyloses was higher in esca  than control stems with a gradual decrease in PLCth over the season for both varieties. In the most exterior xylem vessels (i.e. produced the latest) this observation is associated with a reduction in theoritical specific hydraulic conductivity (kts) of non occluded vessels in esca symptomatic Sauvignon blanc plants. At the end of the season, esca symptomatic stems produced more vessels and in higher density, but  they were smaller than in control stems. Finally, this study highlighted the impact of esca disease on the physiology, growth, cambial stem activity and thus the ability to regrow with the support of new xylem vessels, for two different varieties.

DOI:

Publication date: June 26, 2023

Issue: GiESCO 2023

Type: Article

Authors

Ninon DELL’ACQUA1, Gregory A. GAMBETTA2, Nathalie FERRER1, Pauline THEODORE1, Chloé E. L. DELMAS1

1UMR SAVE, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France
2UMR EGFV, 71 avenue Edouard Bourlaux, F-33140 Villenave d’Ornon, France

Contact the author*

Keywords

grapevine, vascular disease, gas exchange, dendrometer, quantitative anatomy

Tags

GiESCO | GIESCO 2023 | IVES Conference Series

Citation

Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.