ANTHOCYANINS AND GENETICS 163 



Brassica. Kajanus (580) has worked with two species B. napus 

 and B. rapa. 



B. napus. As regards the colour of the root, distinction must be 

 made between upper and lower parts. Anthocyanin is only found in 

 the upper part, which may be violet-red, intermediate, or green. When 

 the root is intense violet, the neck (the lower basal portion of the stem) 

 is also violet-red. If the root-colour is reddish only, the neck is usually 

 green. Hence there are three classes : 



1. Red with red neck. 



2. Red with green neck. 



3. Green with green neck. 



It has been deduced from crossing the varieties that there are 

 two factors involved in anthocyanin pigmentation, i.e. P x which gives 

 pale violet-red, and P 2 which gives deep violet-red colour. P 2 is 

 dominant to P A . When both Pj and P 2 are absent, the root is green. 

 The differentiation between the classes is often not sharp. 



B. rapa. Here also anthocyanin is only found in the upper part of the 

 root, which may be violet-red (deeper or paler), or if pigment be absent, 

 green. The violet-red colour may be continuous or blotched. It has 

 been deduced, from crossing varieties, that anthocyanin is due to the 

 presence of one dominant factor, P, and when this is absent, the root 

 is green. 



Canavalia cnsiformis (Leguminosae). Lock (504) showed pink 

 colour in the flower to be dominant, or nearly so, to white, the latter 

 reappearing in F 2 . Absence of red pigment from the testa (the author 

 does not. state whether this is anthocyanin) is dominant to red. In F 2 

 red reappeared, but in nothing like its former intensity. Some of the 

 plants of F 2 bore mottled grains, but in these also the pigmented patches 

 were of a very faint reddish colour. In F 2 , plants with no red pigment 

 in the testa were more numerous, probably three times so, than those 

 with reddish and mottled testas taken together. 



Canna indica. Inheritance of anthocyanin when red- are crossed 

 with green-leaved plants. Honing (608). 



Cattleya. Hurst (502, 531, 540, 596) notes that purple pigment is 

 dominant to its absence in the flower. 



Clarkia eleyans. Bateson (524) states that the magenta-flowered 

 type is dominant to the salmon-pink variety. 



Corchorus capsularis. Finlow & Burkill (572) investigated the 

 inheritance of anthocyanin in the Indian Jute plant. As regards pig- 

 mentation 33 races were broadly classified into the following types: 



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