A novel analysis of grapevine berry tissue demonstrates a variety-dependent correlation between tissue vitality and berry shrivel

Abstract

Background and Aims: For Vitis vinifera L. berries late in ripening, varietal differences have been found in tissue vitality and water relations linked to berry shrivel. Berry shrivel impacts on quality attributes. Here we quantified berry tissue vitality and shrivel across a broader range of varieties. Methods and Results: Berries from 22 varieties (similar °Brix at harvest maturity) were sectioned longitudinally at the centre and stained to measure tissue vitality and morphology. An analysis tool using MATLAB®R2008a (The Mathworks, Inc, Natick, MA, USA) quantified vitality and morphology, from which a shrivel index was developed. There was a correlation between shrivel and vitality across all varieties, such that greater vitality was associated with less shrivel. Similar within-variety correlations occurred for some varieties. Three clusters were identified across the varieties that reflected different degrees of tissue vitality and shrivel. Patterns of tissue vitality within the berry were also identified that appeared to differentiate between white and red winegrape varieties. Conclusion: Tissue vitality and shrivel indices separated varieties into distinct clusters that indicates mechanistic differences in the way cell vitality in the mesocarp is linked to berry water relations. Significance of the Study: Cell death before harvest may impact on berry quality. Tools to identify the onset of cell death and shrivel may allow more refined measures of quality and maturity assessment.