Development of Table and Raisin Grapes With High Anthocyanins Using a Leaf Disk Assay.

Authors: Ramming, David; Cousins, Peter

Submitted to: International Society for Horticultural Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2010
Publication Date: 7/2/2010
Citation: Ramming, D.W., Cousins, P.S. 2010. Development of Table and Raisin Grapes With High Anthocyanins Using a Leaf Disk Assay.. International Society for Horticultural Science Meeting. P. 172.

Interpretive Summary:

Technical Abstract: Anthocyanins are considered an excellent source of antioxidant phytochemicals for health benefits. The majority of wine, table and raisin grapes have anthocyanins only in their colored skin. Anthocyanin content of grapes would be increased if their flesh also contained anthocyanins. Rubired wine grape has black skin and red flesh berries. It was used as a pollen parent to introgress red flesh in a cross with a seedless female flowered table grape selection C33-30. It has red skin and white flesh berries. The F1 progeny segregated in a 3 colored:1 white skin and 1 red:1 clear flesh ratio for colored berries. Seedlings expressing the highest level of anthocyanins in the flesh and skin were equivalent to Rubired. Seven modified backcross families were created by crossing red flesh seeded F1 selections with seedless red skin table or white skin raisin grapes. Skin color segregated as a single dominant gene as expected. One red flesh parent was heterozygous for skin color and the rest were homozygous. Only seedlings with colored skin had red flesh. Flesh color segregated as a 1 red:1 clear in three of the families or in a 2:1 ratio indicting either a single dominant gene or several genes, with red flesh being predominant. One red flesh parent produced an abnormally high percentage (>80%) of red flesh seedlings. The assay consisted of placing leaf disks in 10% sucrose solution and observing the development of anthocyanins after 5-10 days under 12 hr photoperiod at 26C. When no anthocyanin developed in the leaf disks, their seedlings had clear flesh with white, red or black skin (30% of population) and could be discarded with confidence. Red skin seedlings with light red to red flesh as well as black skin with dark red flesh were identified accurately (>50% red in leaf disk). In some cases seedlings with red or black skin and clear flesh produced anthocyanins in the leaf disks and were not easily differentiated from black skin with light red or red flesh.