HYBRIDIZATION OF VITIS ROTUNDIFOLIA 
INHERITANCE OF ANATOMICAL STEM CHARACTERS 
By C. F. Williams, Assistant 
Division of Horticulture 
In plant breeding, especially of horticultural crops, little or no 
attention lias been paid to anatomical characters. Only those of weight, 
size, color, etc., and such physiological characters as sugar, starch, and 
protein content have been studied. In fact, rarely is a cross effected 
in which the anatomy of the parents differs sufficiently to make possible 
any comparison. However, in hybridizing Vitis rotundifolia with 
other species of Yitis, individuals with considerable difference in 
anatomy have been successfully crossed and the hybrid vines obtained 
are of interest from this viewpoint. It is possible to examine the hybrid 
stems not only for such superficial characters as smoothness, color, 
hardness, size, etc., but also for the fundamental anatomical structure 
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which is the basis of these, and therefore the critical point of attack 
for a genetical study. 
Vitis rotundifolia , the southern muscadine grape, differs considerably 
from other species of the genus Yitis, especially in certain of the stem 
characters. Gray (1) has divided the genus Yitis into two sub-genera. 
Under one, Muscadinia (Planch.) he places V. rotundifolia and under 
the other, Euvitis (Planch.), he includes all other grapes. Small (2) 
has reserved the genus Yitis for the bunch grapes proper and makes 
a separate genus for the muscadine grape, namely Muscadinia (Small). 
This will give some idea of the extent to which V. rotundifolia species 
differ from the other species of Yitis. Only those differences that affect 
the material under discussion will be considered here. 
The hybrid vines on which the following report is based are some 
grown in determining the limits of hybridization of Vitis rotundifolia 
with other species of Yitis. The particular crosses used are as follows: 
TABLE 1. PARENTAGE OF HYBRIDS 
Year 
Made 
No. OF 
Vines 
Description of Cross 
1917 
26 
V. vinifera (var. Malaga) x V. rotundifolia 
1916 
7 
V. bourquiniana (var. Herbemont) x V. rotundifolia 
1912-16-18 
26 
Hybrid (Labrusca x Aestivalis x Vinifera var. Win- 
chell) x V. rotundifolia. 
1917 
1 
Hybrid (Winchell x V. rotundifolia) x V. rotundifolia 
This does not mean that these are the only crosses of V. rotundifolia 
that have been secured. Other hybrids obtained have not been used 
