DELAYED GERMINATION AND THE 

 ORIGIN OF FALSE WILD OATS 



R. J. Garber and K. S. Quisenberry* 

 West Virginia Agricultitral Experiment Station 



IN a recent issue of the Journal of 

 Heredity one of the writers pre- 

 sented evidence concerning the 

 origin of false wild oats, which indi- 

 cates that they owe their origin to mu- 

 tations rather than to natural crossing. 

 Nilsson-Ehle^t, who was first to postu- 

 late mutations as the cause of false 

 wild oats, has published" more evidence 

 in favor of his theory. 



Atwood' pointed out that delayed 

 germination occurs in Avcna fatiia. 

 He maintained that the restriction of 

 oxygen by the seed coats was a limiting- 

 factor in germination and found that 

 searing the seed coats with a hot needle 

 materially increased the percentage of 

 germination. Inasmuch as delayed 

 germination exists in A. fatua one 

 would naturally expect to find it also 

 in false wild oats, provided false wild 

 oats owe their origin to natural cross- 

 ing between A. fofua and A. sativa. In 

 the present paper are reported data ob- 

 tained in an experiment made to de- 

 termine the relative degree of de- 

 layed germination in false wild oats 

 and in the second hybrid generation 

 of certain crosses between A. sativa 

 and A. fatua. 



Methods 



The plants used in this experiment 

 were grown in the plant-breeding nur- 

 sery on the Agronomy farm during the 

 summer of 1922, from seed planted on 

 April 3. At harvest time, which oc- 

 curred between July 14 and July 21, 

 the panicles of each plant were placed 

 in a separate envelope and allowed to 

 dry thoroughly in the sunshine before 



being stored in the laboratory. On 

 September 15, kernels of all the plants 

 reported on were placed in a standard 

 germinating chamber. At the end of 

 six days the germinated kernels were 

 counted and removed. The remaining 

 kernels were again placed in the cham- 

 ber where they were left imtil Sep- 

 tember 28, when the final count was 

 made. Before returning the kernels to 

 the germinator some of them were 

 treated either by searing the seed coats 

 with a red-hot needle or cutting 

 through the seed coats with a razor. 



The seed-sample of each plant ex- 

 cept in sixty instances consisted of 

 twenty-five lower seeds. None of the 

 upper seeds of an oat spikelet was 

 used in the germination test. Because 

 of scarcity of seed, each of twenty-one 

 samples contained from ten to fourteen 

 seeds inclusive and each of thirty-nine 

 samples contained from fifteen to 

 twenty- four seeds inclusive. In this 

 test rag dolls were used as recom- 

 mended by Holbert and Hofifer^ for 

 use in the germination of corn. From 

 eleven to twenty-three samples were 

 placed in each rag doll. 



During the germination test the tem- 

 perature was controlled by means of a 

 water jacket and an ice chamber. Tem- 

 perature readings were made morning, 

 noon, and evening. From September 

 15 to September 21, when the first 

 germination-count was made, the tem- 

 perature was maintained between 17° C. 

 and 19°C. From September 21 to 

 Septemper 28 when the second and 

 final germination-count was made, the 

 temperature was maintained between 

 ]6.5°C. and 19.5°C. with the excep- 



*Approved by the Director of the West Virginia Experiment Station. 

 fFor Numbered References, see Literature Cited, at end of article. 



267 



