R.J. Bruce, K.S. Powell, S.A. Robinson, S. Norng
Grapevine phylloxera (Daktulosphaira vitifoliae Fitch) is an insect that establishes populations on the root system of grapevines, causing the formation of galls on European grapevine Vitis Vinifera L. and ultimately resulting in plant death. As populations increase on the root system and vine health declines the chemical composition of the foliage, in the form of pigments, changes with the resulting leaf chlorosis often being the initial visual indication of phylloxera infestation. Once chlorotic leaves are obvious, the infestation is already well established, and has generally spread to a broader area within the vineyard. Being able to detect pre-visual phylloxera-specific chemical changes as an indicator of infestation would be a significant step in the direction of early phylloxera detection, and may aid in the containment of new infestations and minimise the potential for spread.
A field trial was conducted in a newly detected phylloxera-infested vineyard in the Yarra Valley region of Victoria, Australia in 2007. Duplicate leaf samples were collected from phylloxera-infested and uninfested V. Vinifera L. ‘Cabernet Sauvignon’ and analysed using high performance liquid chromatography (HPLC) for a variety of photosynthetic and photoprotective pigments. Pigments quantified included neoxanthin, chlorophyll a+b, β-carotene, violaxanthin (V), antheraxanthin (A) and zeaxanthin (Z). Statistical analysis of the results indicated changes in the ratios and the concentration of some leaf pigments appeared to be correlated with the relative abundance of phylloxera populations on the root system. In particular the proportion of the pool of xanthophyll photoprotective forms (AZ/VAZ) increased exponentially as the abundance of emerging phylloxera increased. With further investigation photosynthetic pigment fingerprinting may prove to be useful for either a stand alone or an integrated (linked to spectral analysis) rapid, non-invasive, phylloxera detection system.
Bruce, R.J., Powell, K.S., Robinson, S.A. and Norng, S. 2011. GRAPEVINE LEAF PIGMENT RESPONSE TO ROOT INFESTATION BY PHYLLOXERA. Acta Hort. (ISHS) 904:93-99
Daktulosphaira vitifoliae, chlorophyll, β-carotene, Vitis Vinifera, xanthophyll cycle, HPLC, detection

Acta Horticulturae