Lindstrom: Chlorophyll Factors of Maize 273 
indications of pollen contamination. 
It is included in the table only to pre- 
sent all the data in this experiment. 
The relations between the various 
factors involved in this cross can be 
studied best by taking two pairs of 
factors at a time. The interrelation 
between the Ww factor pair, govern- 
ing chlorophyll inheritance and the 
Su su pair, determining starchy and 
sugary endosperm, will be considered 
first. Using the data from the three 
ears (2955, 2956, 2969 ) that show no 
evidence of pollen contamination, the 
following results are obtained when the 
starchy seeds (indicated by Sw) are 
considered separately from the sugary 
(sw) seeds :— 
Suw Suw suW suw 
Observed 507 161 155 46 
Calculated 489 163 163 54 
The actual or observed results approxi- 
mate a 9:3:3:1 ratio very closely. The 
starchy seeds show a proportion of 3 
green seedlings to 1 white as do the 
sugary seeds. In fact, the closeness of 
fit, as measured by P is .53, which in- 
dicates that there is good agreement 
between the facts and the hypothesis 
of independent Mendelian inheritance 
between the chlorophyll and endosperm 
factors. 
The numbers are sufficiently large 
and the approximation to the theoreti- 
cal expectancy is so close that we can 
be reasonably certain that w and su 
are not linked in inheritance. In 
other words, the albino chlorophyll 
factor is not on the same chromosome 
as the sugary endosperm factor. 
ALEURONE AND CHLOROPHYLL FACTORS 
If the relation between aleurone 
color and chlorophyll development is 
considered next, similar results obtain. 
In this case the purple aleurone grains 
(indicated by R) are classified sepa- 
rately from the colorless grains (7). The 
green and white seedlings resulting 
from these two types of seed are as 
follows: 
IRV IRA NE GADD 
Observed 482 155 180 52 
Calculated 489 163 163 54 
Both purple and colorless seeds give 
approximately 75% green and 25% 
white seedlings, resulting in a 9:3:3:1 
ratio. The calculated value for P is 
.51 which means good agreement be- 
tween actual and theoretical results. 
From such data we can draw the 
conclusion that w and ¢ are not linked, 
but that the chlorophyll factor w is 
located in a different chromosome than 
is the aleurone factor 7. 
From the data in Table I, it can be 
shown that the 7 and sw factors also 
are independently inherited. When 
grouped according to these factors the 
data are as follows: 
RSu Rsu rSu rsu 
Observed 489 148 179 53 
Calculated 489 163 163 54 
The agreement between the actual and 
the theoretical results is not as good as 
in the preceding cases since the value 
TABLE I: F Seedlings from Four Self-pollinated F Plants of the Composition i i Pr Pr A A C C 
Ry Su su Ww* 
Pedigree No. | Purple Starchy Purple Sugary Colorless Starchy | Colorless Sugary 
Seed Seed Seed Seed 
Green White Green White Green White Green White 
2955 148 58 56 12 56 16 18 7 
2956 74 ii 18 6 20 10 6 1 
2969 144 48 42 14 65 12 15 6 
Total 366 123 116 32 141 38 39 i4 
Theoretical 367 122 122 41 122 41 41 14 
2959 87 18 25 5 48 2 8 0 
Total 453 141 141 37 189 40 47 14 
Theoretical 448 149 149 50 149 50 50 17 
*Original cross made by Mr. E. G. Anderson of the Department of Plant Breeding, New 
York State College of Agriculture at Cornell University. 
