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X-ray imaging of 30 year old wine grape wood reveals cumulative impacts of rootstocks on scion secondary growth and harvest index


Quigley, Michelle Y.; Mullins, Joey; Chitwood, Daniel H. (2022), X-ray imaging of 30 year old wine grape wood reveals cumulative impacts of rootstocks on scion secondary growth and harvest index, Dryad, Dataset,


Annual rings from vines in a 30 year old, California rootstock trial were measured to determine the effects of 15 different rootstocks on Chardonnay and Cabernet Sauvignon scions. Viticultural traits measuring vegetative growth, yield, berry quality, and nutrient uptake were measured at the beginning and end of the lifetime of the vineyard.

X-ray Computed Tomography (CT) was used to measure ring widths in 103 vines. Ring width was modeled as a function of ring number using a negative exponential model. Early and late wood ring widths, cambium width, and scion trunk radius were correlated with 27 traits. 

Modeling of annual ring width shows that scions alter the width of the first rings but that rootstocks alter the decay thereafter, consistently shortening ring width throughout the lifetime of the vine. The ratio of yield to vegetative growth, juice pH, photosynthetic assimilation and transpiration rates, and stomatal conductance are correlated with scion trunk radius.

Rootstocks modulate secondary growth over years, altering hydraulic conductance, physiology, and agronomic traits. Rootstocks act in similar but distinct ways from climate to modulate ring width, which borrowing techniques from dendrochronology, can be used to monitor both genetic and environmental effects in woody perennial crop species.


In 1991 rootstocks were planted near Lodi in San Joaquin County, California, before scionwood was whip-grafted to the planted rootstock in 1992. The soil type was a Tokay fine sandy loam soil. Vines were grafted to the following rootstocks: Freedom, Ramsey, 1103 Paulsen, 775 Paulsen, 110 Richter, 3309 Couderc, Kober 5BB, SO4, Teleki 5C, 101-14 Mgt, 039-16, 140 Ruggeri, Schwarzman, 420 A, and K5132. The two scion varieties were Chardonnay (selection FPS 04) and Cabernet Sauvignon (selection FPS 07). Rows were oriented east-west with vine spacing of 2.13 m by 3.05 m. The trellis system was a bilateral cordon with fixed foliage wires and the vines were cordon trained and spur pruned. The experimental design was a randomized complete block design, split between Chardonnay and Cabernet Sauvignon. There were four replications per treatment (rootstock). There were eight or nine vines per plot, except for Kober 5BB and SO4, which had four or five vines each, to fit all treatments in the block. Data for viticultural traits from the vines that were scanned in this dataset collected 1995-1999 and 2017-2020 can be found on GitHub at the following repository:

In fall 2021, segements of scion trunks were cut and sent to Michigan State University (East Lansing, Michigan) for X-ray Computed Tomography (CT) scanning and analysis. CT images were taken from the middle of the vine samples. The total image height was approximately 95 cm. Images were scanned at 75 kV and 450 µamps in continuous mode with 2880 projections and 2 frames averaged on a North Star Imaging X3000. The focal spot size was 33.75 microns and the detector was set to 12.5 frames per second. Scan time was 8 minutes. Scans were reconstructed using the efX-CT software from North Star Imaging (Rogers, MN). Final voxel resolution was 63.9 µm and pixel resolution was 63.9 µm by 63.9 µm (0.00639 cm by 0.00639 cm). From each 3D CT image, three individual slices were taken for analysis. One slice was from the top of the image, one was from the middle of the image, and the last was from the bottom of the image. All slices were aligned to be taken perpendicular to the vine samples. In ImageJ, a thin line was drawn from the center of the pith to the bark. Landmarks were placed as follows delimiting the following features in order, from the center of the wood outwards: landmark 1, pith and ring 1 early wood, landmark 2, ring 1 latewood, landmark 3, ring 2 early wood, landmark 4, ring 2 late wood, landmark 5, ring 3 early wood, landmark 6, ring 3 latewood, landmark 7, ring 4 early wood, landmark 8, ring 4 latewood, landmark 9, ring 5 early wood, landmark 10, ring 5 latewood, landmark 11, ring 6 early wood, landmark 12, ring 6 latewood, landmark 13, ring 7 early wood, landmark 14, ring 7, late wood, landmark 15, ring 8 early wood, landmark 16, ring 8 late wood, landmark 17, remaining outer rings, landmark 18, cambium, landmark 19, end of cambium and beginning of bark. Euclidean distance converting from pixels to centimeters was used to calculate ring widths. Models of ring width as a function of ring number were fitted with the three slices per each vine. Ring width measurements across the 3 slices for each vine were averaged for trait correlation analysis.

Usage Notes

These usage notes are included as a ReadMe.txt file with the data. This dataset consists of 336 .tif files represeting 2D slices of X-ray CT reconstructions from the scions of 112 grafted vines (3 slices per vine). The filename indicates the following data for each image separated by underscores: scion_rootstock_row_column_slice. Scion is either "Cab" or "Chard" for Cabernet Sauvignon and Chardonnay, respectively. Rootstock indicates the rootstock the scion was grafted to, one of the following 15 varieties: Freedom, Ramsey, 1103 Paulsen, 775 Paulsen, 110 Richter, 3309 Couderc, Kober 5BB, SO4, Teleki 5C, 101-14 MGT, 039-16, 140 Ruggeri, Schwarzman, 420 A, and K51-32. Data from the vine in position row 10, column 3 was mislabeled for its rootstock (the files are labeled as "wrong rootstock") and should be ignored, but it is included for completeness. Row and column represent where in the vineyard the vine was taken from, which can be found on the included map in the .pdf named "vineyard_map.pdf". Each of the three slices is named as "Slice XXX" where XXX indicates the voxel number along the z axis of the original X-ray CT reconstruction the slice was taken. Embedded in each .tif file is landmark data indicating the boundaries of the early and late ring wood for rings 1-8, the remaining outer rings, and the cambium. Viticultural data associated with these vines can be found posted on the GitHub repository at


USDA National Institute of Food and Agriculture

AgBioResearch, Michigan State University

National Science Foundation Plant Genome Research Program, Award: 1546869