GAMETE SELECTION FOR SPECIFIC COMBINING ABILITY 379 



selfed and crossed to the opposing single cross parent of the double cross. 

 Table 24.3 gives the number and type of test crosses made. 



Approximately 60 inbred X variety Fi plants from each of the three sources 

 were selfed and crossed to the testers. Selection of the better Fi plants at 

 harvest reduced the number for further study to 35, 32, and 38 as listed in 

 Table 24.3. P:xperiments 1 and 2 were tested in separate randomized blocks 



TABLE 24.1 

 PERFORMANCE OF A344 AND A334* 



* As indicated by average moisture and yield when crossed in 

 non-parental single cross combinations of Minhybrid 602 (A344X 

 A334) (A357XA392) and Minhybrid 607 (A344XA334) (A357X 



A38.S). 



TABLE 24.2 

 PERFORMANCE OF A25, A334, A73, AND A375* 



* As indicated by moisture and yield in non-parental single 

 crosses of Minhybrid 406 (A25XA334) (A73XA375J. 



using two replicates at each of three locations in central Minnesota. Data 

 from the two testers were averaged to give a total of 12 replicates as a test 

 for each gamete. Experiments 3 and 4 were also grown in randomized blocks 

 with three replicates at each of four locations in southern Minnesota. One 

 location of experiment 3 was discarded and one replicate of experiment 4 was 

 abandoned prior to harvest. 



On the basis of yield trial results in 1947, gametes were selected from all 

 varieties and from two inbreds, for use as parents in the development of 

 new lines by straight selfing and by backcrossing to the sampler inbred. 



Study of the performance indices and agronomic characters of the test 

 crosses led to the selection of three Golden King gametes and four Murdock 



