66 
I. NAGAI : 
practically no cliromogenic substance whereas the rest of them is prominent. 
This is to indicate that a dominant inhibitor is present in the green and 
yellow. Let G be the gene for the green colour and g for the yellow. Fur¬ 
ther we assume that C and c are the chromogens. The amount of chromo- 
genic substance produced by c is less than that produced by G. Let 0 be 
the chromophelein which converts the chromogenic substance to brown pigment 
and o to reddish brown. It is assumed that the same chromogenic substance 
is converted to the purple anthocyanin by R but not by r. The gene I 
inhibits the full development of the pigment in the seed coat and by i no 
such effect is done. The inhibitory action of the gene I seems to extend to 
the action of C and R. Accordingly the different colour types may be de¬ 
signated as follows : 
COGRI 
COgRI 
COGrI 
COgrI 
COGRi 
COgRi 
COGri 
COgri 
Cogri 
cOgri 
Blue tinged green 
„ „ yellow 
Non tiuged green 
„ „ yellow 
Black (green hypostatic) 
,, (yellow hypostatic) 
Brown (with green tinge) 
,, (without green tinge) 
Beddish brown 
Buff 
The genetic composition of the parental plants of the cross between 
“Haiiro” and “Tanishi” would be CCOOGGrrii and CCOOggRRII re¬ 
spectively. The F x plant is therefore heterozygous to three genes Gg Rr and 
li but homozygous to C and 0. The different phenotypes appeared in F, are 
due to the recombination of these genes. Thus : 
Blue tinged 
Black 
Non tinged 
Brown 
Total 
Yellow 
COgRI 9 
COgRi 3 
COgrI 3 
COgri 1 
16 
Green 
COGRI 27 
COGRi 9 
COQrl 9 
COGri 3 
48 
Anthocyanin present 48 
Anthocyanin absent 16 
64 
