96 INHERITANCE OF ANTHOCYAN PIGMENT IN PADDY VARIETIES 



(4) Colour due to three and four interacting factors. 



The cross discussed below was made in the season 1912 between a wholly 

 green, awnless variety with white stigma, Chittagong No. 25 (Plate II, figs. 

 5-8), and a variety with reddish purple leaf-sheaths, apiculus and awns, and 

 a deep blue-black stigma, Chittagong No. 9 (Plate II, figs. 1-4). Four 

 successful crosses were obtained, but unfortunately during the absence of 

 the writer on tour, three of the Fj plants were eaten by insects and the result 

 of only one, C25 $ X C9 9 are so far available. The cross has since been 

 repeated, but the results will not be forthcoming for another year. 



In the Fi the colour characters appeared to be almost wholly dominant, 

 thouf^h the colours were not quite so pronounced as in the coloured parent. 

 Five hundred and twenty-nine plants were bred to the Fo generation during 

 the season 1914 and gave the following figures with reference to colour 

 characters :— 



(1) Red leaf-shcatlis ; red apiculus ; coloured stigma .. 180 | ^. 



(2) „ „ white stigma .. "^ M 040 



(3) Green leaf-sheaths ; green apiculus ; ,, . . 279 / 



i.e., coloured leaf-sheath and apiculus 250 : green . . 279 



Expectation 223-1 : . . 305-9 



Coloured stigma 180 : white . . 349 



Expectation 167-3: .. 361-7 



Confirmation of the above figures has also been obtained from the 

 analysis of the offspring of a natural hybrid selected from the pure line 

 plot of Chittagong Nc. 9 in 1914, only in this example tlie male 

 parent is unknown. In the present season 1915 the following figures were 

 obtained : — 



(1) Red leaf-.sheath ; red apiculus ; coloured stigma .. 28 j 47 



(2) „ „ white stigma .. ^^) I71 



(3) Green leaf-sheath ; green apiculus ; white stigma . . 52 J 



i.e., coloured leaf-sheath and apiculus 47 : green . . 52 



Expectation 41-7: .. 57-3 



Coloured stigma 28 : white ,. 71 



Expectation 31-3: .. 67'7 



Here the figures closely approximate to the expectation on a basis of three 



interacting factors for the leaf-sheath and apiculus colour, and four for the 



stigma, otherwise this case is exactly comparable to those in Table III, and 



the constitution of the F2 types will be as under, using B for the extra 



colour factor in the stigma : — 



81 — CRPB — Coloured leaf-sheath, apiculus and stigma. 

 27— CRPb— „ „ , stigma white. 



