298 



The Journal of Heredity 



A 9:7 Ratio — A plant of the Bod- 

 wick variety grown from seed obtained 

 from the ^Montana Experiment Station 

 was crossed with another plant from 

 a family grown for several years at 

 Cornell for genetical studies. Both of 

 these plants were selfed and both seg- 

 regated for germless in a 3:1 ratio. 

 The first generation from this cross 

 had all seeds normal and the second 

 segregated as shown in Table III. 



The occurrence of a 9 :7 ratio in the 

 second generation shows that two inde- 

 pende;it factors for germless were pres- 

 ent in this cross. The germless charac- 

 Ijers present in the parents were pheno- 

 typically alike, but genetically different. 



Conclusions — From the data obtained 

 it can be concluded that the germless 

 phenotype may be expressed by several 

 genetically different factors. The evi- 

 dence presented shows that at least 

 four different factors were present in 

 the families discussed above. Three 

 of them are triplicate genes and the 

 fourth one, as far as it is known, acts 

 as an independent factor. 



Frequency of Germless Seeds Among 

 Cultivated Varieties of Maize 



Several commercial varieties of corn 

 were recently included in the stocks 

 grown for genetical studies, because 

 they possessed some seedling characters 



of genetical interest. Progenies of 

 those varieties which were selfed for 

 two or three generations have been 

 examined for the germless character. 

 It was found that selfed progenies 

 from about seventy-five per cent of the 

 commercial varieties examined had 

 some germless seeds. The ratio in 

 which the germless character segre- 

 gated was different in different varie- 

 ties, as can be seen in Table IV. 



Among inbred varieties grown at 

 Cornell for breeding purposes, Profes- 

 sor R. G. Wiggans observed germless 

 seeds in the following: Cornell II, Al- 

 vord's White Cap Yellow Dent, Onon- 

 daga White, and Latting's Red Cob 

 White. 



Summary 



An inherited character called germ- 

 less (Gni gm) is described. In germ- 

 less seeds the endosperm is developed 

 normally but the embryo is almost or 

 entirely lacking. 



The germless condition is I'ecessive 

 to normal. Segregations in 63:1, 15:1, 

 3:1 and 9:7 ratios were observed, 

 which indicates the presence of at least 

 four genetic factors for germless. 

 Three of them are triplicate genes. 



Germless seeds were found in the 

 majority of commercial varieties of 

 which selfed progenies were examined. 



Table I — Data rei/arding tlic segregation of ears for germless seeds in the first generation 

 of certain crosses of Golden Bantam sweet corn. 



Family 

 No. 



Normal 



Germless 



Total 



Ratio 



Expected 

 Germless 



Difference 



