|Authors: ||J. Lu, L. Schell, D.W. Ramming|
|Keywords: ||Muscadine grapes, bunch grapes, embryo rescue, stenospermocarpy, seedlessness, disease resistance|
The genus Vitis contains two subgenera: Euvitis Planch. (bunch grapes) and Muscadinia Planch. (muscadine grapes). Vitis vinifera in the subgenus Euvitis is the predominant grape species grown worldwide for fresh or for processed fruits.
The muscadine grapes (V. rotundifolia) originated in the south-eastern United States and are distinguished from the Euvitis species morphologically and cytologically.
They are characterized by high disease and pest resistance, and an unique flavour.
The major problem for gaining wider acceptance of muscadine grapes is its relatively low fruit qualities compared to the excellent fruit of vinifera. Attempts to produce V. rotundifolia x V. vinifera hybrids that combine good fruit quality and disease resistance have been made by grape breeders for many years.
Limited success was only reported when the V. vinifera was used as seed parents.
The objectives of our breeding program are to combine good fruit quality from V. vinifera grapes and high disease resistance from V. rotundifolia grapes.
More than 50 cross combinations between V. vinifera and V. rotundifolia have been made since 1993. Limited success was achieved in some crosses and only two hybrids were produced from the crosses when the muscadine grapes were used as the female parent.
In these hybrids, many morphological and biological characteristics, such as leaves, stems, tendrils, time of bud break, bloom date, and ripen date, are intermediate between the parents.
Some of the hybrids are partly fertile.
Evaluation for disease resistance of these hybrids indicated that they are resistant to Pierce's disease, anthracnose disease and downy mildew, which are the limiting factors to growing V. vinifera in the hot, humid climate of south-eastern United States.
These hybrids can be used as bridges to carry viticulturally important genes from V. vinifera to the muscadine grapes and vice versa, to transfer disease resistant genes from V. rotundifolia to V. vinifera grapes.
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