ANTHOCYANINS AND GENETICS 183 



2 (A). Loss of the B factor from the flower will give red antho- 

 cyanin. Accompanying this there is a corresponding change in the 

 pigment of the stem and leaves. Ex. Antirrhinum: rose dore and 

 bronze varieties ; the same red pigment is developed in the stem and 

 leaf. Primula sinensis: 'Orange King'; the same pigment appears 

 in the stem and petioles. Salria Horminum : red-flowered plants have 

 red inflorescence bracts. Pisum : red flowers are accompanied by red 

 spots on the testa and red leaf-axils. 



2 (B). Blue-flowered varieties of Primula sinensis develop blue 

 anthocyanin in the stem. 



3. In pale varieties (flower-colour), there is less anthocyanin in 

 the stems and leaves. Ex. Primula sinensis : pale varieties and faintly 

 coloured stems; light-flowered varieties and light stems; 'Sirdar' 

 flower-colour and the pigment in the collar of the stem. Gossypium 

 (Indian): plants with petals with a basal spot have green leaves; 

 plants with red petals have leaves suffused with red. 



4. Deep varieties. Ex. Antirrhinum: the deepest flower-colours 

 have red leaves and stems. Primula sinensis: deep flower-colours 

 have deep red stems. 



Then follow the more complex cases in which pigmentation in 

 different organs appears to be inherited independently, either partially 

 or completely. Ex. Helianthus: flower-colour apart from stem colour 

 in the purple variety. Lathyrus odoratus : coloured flower and coloured 

 leaf-axil; yet at the same time there may be coloured flowers and a 

 colourless leaf-axil. Oenothera: red bud pigmentation with green 

 stems; green buds with red stems. Primula sinensis: white flowers 

 and red stems. Zea Mays : independent inheritance of colour in cobs, 

 pericarp, silks, etc. 



HETEROZYGOUS FORMS. 



Just as in the case of factors for other characters, so also in the 

 case of factors concerned with pigmentation we find heterozygous 

 forms. The one of most frequent occurrence is that due to the inheri- 

 tance in the zygote, from one parent only, of the factor which actually 

 produces colour (anthocyanin). We find it, for instance, in the following 

 genera : 



In Atropa Belladonna: when the red-stemmed, brown-flowered 

 type is crossed with the green-stemmed, yellow-flowered variety, the 

 colour in stems and flowers of F x is less intense than the parent (Saunders, 

 475). 



