CHARACTERS IN AX UPLAND-EGYPTIAN COTTON HYBRID. 
PETAL SPOT. 
31 
The behavior of petal spot in the Holdon-Pima hybrid (fig. 27) indicated dominance 
of the presence of the spot but in a reduced condition in F! and a 3 to 1 ratio for its 
presence as contrasted with its complete absence in F ? , the degree of development 
when present being apparently conditioned by modifying factors. 
. Balls (4, pp. 37, 38) reported that in an upland-Egyptian hybrid of which the 
Egyptian parent had a fully developed spot and the uplana parent none, the 
distributions in two F 2 populations of full, intermediate, and no spot, respectively, 
were: 23-42-31 and 11-22-18. These figures indicate a 2 to 1 rather than a 3 to 1 
ratio if presence of the spot in any degree be contrasted with its complete absence. 
Small F 3 progenies of four F 2 individuals gave the distributions shown in Table 7. 
Table 7. — Distribution of petal spot in the progenies of four F 2 individual upland' 
Egyptian cotton hybrids. 
Fj parent. 
Full spot 
Intermediate spot 
Do. 
No spot 
Interme- 
Full spot. 
diate 
spot. 
6 

2 
12 
1 
2 


No spot 
In a later publication (6, pp. 138, 139) it is stated that " 'spotless' breeds true, 
while 'full' may either breed true or break, and intermediates break in at least two 
different ways. Probably there are again two allelomorphic pairs concerned." 
McLendon (34, pp. 185-190), crossing sea-island cotton, which has spotted petals 
much like those of Egyptian cotton, with spotless varieties of upland cotton, found 
that in Fj the spot was intermediate in size and intensity. In most of the F 2 progenies 
the ratio of individuals having the petals spotted in any degree to those having 
spotless petals was less than 3 to 1, but in a few progenies this ratio was closely 
approximated or was even exceeded. 
Leake and Prasad (82, pp. 127, 128) reported results from crossing a Chinese cotton 
having no petal spot with an Indian cotton possessing a well-developed spot which 
indicate complete dominance of the spot in F|. 
ANTHER COLOR. 
Anther color in the Holdon-Pima hybrid showed partial dominance in F x of the 
yellow color of the Pima parent, and the mode in F 2 was even higher than the F! 
mean. There was some indication of a bimodal distribution in the second generation 
(fig. 29), the pale color appearing to be a simple recessive. 
Balls (4, p. 38) described the first generation of an upland-Egyptian hybrid as 
having anthers of a " pale yellow " color as contrasted with "rich yellow " in Egyp- 
tian and " buff " in upland. In F 2 and F 3 his classification was admittedly unsatis- 
factory, but the same type of segregation as he obtained for petal color was indicated. 
In another publication (6, pp. 140, 141) he states that a 1:2:1 ratio was obtained in 
F 2 and concluded that only one pair of allelomorphs was involved in this case. 
McLendon {34, pp. 191-198) in his sea-island-upland hybrids obtained results for 
anther color similar to those which he obtained in regard to petal color, and in fact 
his data as presented would indicate that the same factor determines the color of the 
petals and the anthers. On the other hand, complete independence of the factors 
for yellow color in the two organs was indicated in the Holdon-Pima hybrid, the F 2 
coefficient of correlation of petal color and anther color having been 0.087 ±0.050. 
BOLL LOCK NUMBER. 
The average per plant of the number of locks of the boll was exactly intermediate 
in F x of the Holdon-Pima hybrid, and the F 2 distribution (fig. 32) was unimodal and 
fairly symmetrical, the evidence indicating that several factors are involved in this 
character. 
Balls (6, pp. 163-166) presents evidence concerning this character in hybrids 
between upland and Egyptian and between different varieties of Egyptian cotton 
which points strongly to the same multiple factor interpretation. 
