APS_July2023

144 532 533 534 Table 3. Berry color of ‘Xinyu’ grapes harvested from vines trained to three different trellis systems. 535 Color values SDTS-H ISDTS-H ISDTS-VH L* 33.27±4.98 a z 25.10±2.32 b 23.85±1.82 b a* 8.92±2.51 a 4.13±1.36 c 5.28±0.57 b b* 1.45±0.68 a -4.05±0.51 b -3.62±0.78 b C* 9.59±1.94 a 5.84±1.19 b 6.43±0.79 b CIRG 4.09±1.11 c 7.45±0.29 a 6.89± 0.15 b z Values are means ± standard deviation of three replicates. Values within rows followed by common 536 letters do not differ at the 5% level of significance, by Duncan’s multiple range test. z Values are means ± standard deviation of three replicates. Values within rows followed by common letters do not differ at the 5% level of significance, by Duncan’s multiple range test. Table 4. Anthocyanin compounds in skins of ‘Xinyu’ grapes harvested from vines of three trellis systems. Table 4. Anthocyanin compounds in skins of ‘Xinyu’ grapes harvested from vines of three trellis 541 systems. 542 Anthocyanin compound SDTS-H ISDTS-H ISDTS-VH Delphinidins (μg·g −1 ) 135.02±2.20 c z 315.99±6.51 a 193.80±23.77 b Petunidins (μg· g −1 ) 55.37±0.90 b 92.98±1.92 a 64.18±7.87 b Malvidins (μg· g −1 ) 190.72±3.11 b 239.18±4.93 a 205.572±25.22 b Cyanidins (μg· g −1 ) 2.27±0.37 b 28.87±0.60 a 28.21±3.46 a Peonidins (μg·g −1 ) 115.35±1.88 b 131.38±2.71 a 133.44±6.37 a Pelargonidins (μg·g −1 ) 1.87±0.03 c 3.45±0.07 a 2.68±0.32 b Total cyanidins proportion (%) 26.49±1.12 a 19.63±0.98 b 25.75±1.13 a Total delphinidins proportion (%) 73.26±0.95 b 80.37±0.98 a 74.25±1.13 b z Values are means ± standard deviation of three replicates. Values within rows followed by common 543 letters do not differ at the 5% level of significance, by Duncan’s multiple range test. 544 545 546 547 Table 5. Concentration and relative proportion of anthocyanins in ‘Xinyu’ grape skins harvested from 548 vines of three trellis systems. 549 z Values are means ± standard deviation of three replicates. Values within rows followed by common letters do not differ at the 5% level of significance, by Duncan’s multiple range test. letters do not differ at the 5% level of significance, by Duncan’s multiple range test. 532 533 534 Table 3. Berry color of ‘Xinyu’ grapes harvested from vines trained to three different trellis systems. 535 Color values SDTS-H ISDTS-H ISDTS-VH L* 33.27±4.98 a z 25.10±2.32 b 23.85±1.82 b a* 8.92±2.51 a 4.13±1.36 c 5.28±0.57 b b* 1.45±0.68 a -4.05±0.51 b -3.62±0.78 b C* 9.59±1.94 a 5.84±1.19 b 6.43±0.79 b CIRG 4.09±1.11 c 7.45±0.29 a 6.89± 0.15 b z Values are means ± standard deviation of three replicates. Values within rows followed by common 536 letters do not differ at the 5% level of significance, by Duncan’s multiple range test. 537 538 539 540 J ournal of the A merican P omological S ociety Anthocyanin compounds in berry skin High total and peel anthocyanin concen trations are the main reason for the deep coloration of ‘Xinyu’ grapes, which is also enhanced by increased total delphinidin con centration. Delphinidin, petunidin, malvidin, cyanidin, and pelargonidin concentrations in berry skin were highest for ISDTS-H and lowest for SDTS-H, but concentrations for ISDTS-H and ISDTS-VH were not always Anthocyanin content (µg·g -1 ) Table 3. Berry color of ‘Xinyu’ grape berry harvested from vines trained to three different trellis systems. letters do not differ at the 5% level of significance, by Duncan’s multiple range test. 537 538 539 540 significantly different (Table 4). Pelargonidin concentrations were lowest for SDTS-H. The proportion of total cyanidins was lowest and the proportion of total delphinidins was high est for ISDTS-H. Methylation was the predominant modi fication observed for anthocyanins. Berries from SDTS-H generally had lowest concen trations of methylated and non-methylated anthocyanins, and nonmethylated anthocy Anthocyanin proportion (%)

Anthocyanin modification

SDTS-H

ISDTS-H

ISDTS-VH

SDTS-H

ISDTS-H

ISDTS-VH

Acetylated

5.30±0.1 c z 5.35±0.1 b

22.07±0.56 a 10.37±0.26 a

8.27±1.24 b 6.26±0.94 b

1.06±0.06 c 1.03±0.01 b

2.72±0.15 a 1.27±0.03 a

1.32±0.08 b 1.00±0.08 b

Coumaroylatedd