92 THE INHERITANCE OF CHARACTERS IN RICE 



The term purple axil is applied, for the sake of convciuciice, to a deep 

 purple colouring of the epidermis oi^ the inside of the sheath. It is most intense 

 in the axil and gradually diminishes as it extends upwards till it disappears 

 about half wa}- up the sheatli (Plate IV, B, 23). 



As will be seen below, tlie above four characters behave as simple 

 dominants to their respective unpigmented types, each character being due to 

 the presence of a simple factor. In the following description the j)resence of 

 these factors will be denoted by the capital letters L, G, S, A, respectively, and 

 their absence by the corresponding small letters. 



The principal material to be considered was derived from the cross between 

 types B, 1 and B, 23 of Plate IV. Reference has already been made to this 

 cross in connexion with purple self -colouring of the leaf-sheath ; this is entirely 

 independent of the above characters and may be disregarded here. 



These two types were plants from pure strains of the variety Busangi, 

 separated by Mr. Hilson on the Government Farm at Samalkota. Their 

 composition, together with that of Fi, may be represented as follows : — 



B, 1 L L G G s s a a 

 B, 23 1 1 g g S S A A 

 Fi L 1 G g S s A a 



In F2 it was found that each character, considered .separately, behaved 

 as a simple dominant, giving a jjresence : ahsencc ratio of 3 : 1. When all four 

 characters were considered together it was found that : — ■ 



'purple lining was associated with purple glumes ; 



purple stigma ,, ,, purple axil ; 



green internode and glumes were associated with jmrple stigma and axil. 



Thus only three types occurred, which may be represented as L G s a 

 L G S A and 1 g S A. The ratio approximated to 1:2: 1 respectively, as 

 shown by the figures in Table XII. It follows that— 



L is coupled with G 



b ,5 ,, . A 



L G repels S A 



Thus the F^ — LI GgSsAa — can form only two types of gamete, 

 viz., L G s a and 1 g S A, which result in the following ratio'in Fo : — 



7, L L G G s s a a : 5, L 1 G g S s A a : 7, 1 1 g g S S A A — i.e., two pure 

 types similar to the parents and a heterozygous type similar to Fi. This 

 was confirmed in Fg as will be seen, from Table XII, 



