164 



HAROLD H. SMITH 



means and non-heritable variances were linearly related for both 1947 and 

 1949 data, and the parental variances were significantly different. 



Tests to reveal the presence or absence of non-allelic interactions were then 

 made according to the method proposed by Mather (1949). Results are 

 shown in Table 10.3. No significant deviations from zero were found if the 

 level of significance was taken as P ^ .01. In each test, however, the P values 

 for number of nodes were less than for plant height or leaf length, possibly 

 owing to non-additive gene effects. 



It was concluded, on the basis of these tests, that for the two characters 



TABLE 10.2 



PLANT CHARACTERS IN THE TWO MOST VIGOROUS VARIETIES OF 



N. RUSTIC A, THEIR F,, F2, AND FIRST BACKCROSS PROGENY 



AND IN SELECTION AKFe)* 



Gen- 

 era- 

 tion 



Pi 

 P2 

 Fi 

 F2 

 Bi 

 B2 

 Fe 



Type 



Olson 68 



34753 



Olson 68X34753... 

 (Olson X34753) self. 



FiXOlson 68 



FiX34753 



Selection Al 



Plant Height 



Mean 



in. 

 47.8 

 28.7 

 43.2 

 40.6 

 47.3 

 36.2 

 55.6 



Total with- 

 in Plot 



d.f. 



141 

 143 

 140 

 149 

 149 

 148 

 133 



Var. 



15.46 

 22.63 

 39.18 

 99.19 

 40.28 

 101.50 

 29.77 



No. OF Nodes 



Mean 



24. 

 21. 



22. 

 23. 

 24. 

 21. 



31.0 



Total with- 

 in Plot 



d.f. 



136 

 106 

 110 

 119 

 138 

 117 

 126 



Var. 



3. 

 10. 



8. 



45 

 10 

 60 



10.52 

 10.49 



45 

 44 



Leaf Length 



Mean 



in. 

 11 

 10. 

 11 

 11 

 11 

 10.8 

 12.0 



Total with- 

 in Plot 



d.f. 



142 

 127 

 131 

 142 

 144 

 135 

 141 



Var. 



0.68 

 0.81 

 0.63 



08 

 10 



0.95 

 0.69 



Least significant diff. at 



5% level 2.55 



1% level 3.42 



1.37 

 1.83 



0.49 

 0.66 



* Summary of 1949 data. 



TABLE 10.3 

 SCALING TESTS FOR AVERAGE ADDITIVENESS OF GENE EFFECTS* 



Character 



Test A 



Dev. 



Var. 



Plant height. 3.6 2.86 

 No. nodes...' 2.8 1.50 

 Leaf length.. 0.9 0.47 



Test B 



Dev. 



Var. 



Test C 



Dev. 



Var. 



2. 13. 03-. 04 0.54.13 0. 25'. 80-. 81 -0.515.48 0. 13 .89-. 90 

 2. 30. 02-. 03-1. 11. 71 0.84. 40-. 41 3.5 6.18 1.40. 16-. 17 

 1.32,. 18-. 19, 0.00.47 0.00 1.00 i 0.5 1.77 0.38 . 70-. 71 



* Based on 1949 means. 



