184 MUTATION AND PLANT BREEDING 



forms into 31 species. Snowden's collection was worldwide and his 

 classification is useful even though his giving races specific rank may 

 be questionable. Characteristics such as plant color, juicy or pithy 

 stem, pericarp color, presence or absence of testa, presence or absence 

 of awns, starchy and waxy endosperm, white or yellow endosperm, 

 dehiscent or indehiscent spikelets, height and duration of growth, 

 are known to be genetic. But the inheritance of the complex of 

 characters that makes up the groups of varieties or races such as the 

 broomcorns, kafirs, feteritas, milos, kaoliangs, hegaris, shallus, sumacs, 

 etc., is not understood. Laubscher (16) has considered modifying 

 complexes to be important in separating the races of sorghum. 

 Reviews of sorghum genetics literature have been made by Martin 

 (20), Myers (23), and Quinby and Martin (31). 



Introduction Into the United States 



Sorghum has been grown in the United States for a little over 

 a century. Accounts of the early introductions and early work with 

 sorghum have been presented by Vinall, et al. (43), Martin (20), 

 Quinby and Martin (31), and Quinby, et al. (30). 



The first sweet sorghum that reached the United States came 

 from China by way of France in 1853 and is now known as Black 

 Amber. Before the distinction between sorghum and sugarcane, 

 Saccharutn officinarum, was well understood, the Indian Service 

 sent seed of this sorghum to the Comanche and Brazos Reserves in 

 Throckmorton and Young Counties in Texas as Chinese Sugar- 

 cane. To this day, farmers in West Texas call sweet sorghum 

 "cane". Fifteen sorgo varieties, several of which survive, were intro- 

 duced in 1857 from South Africa. Two other sweet sorghums were 

 introduced in 1881 and 1891, the first from Natal, South Africa, and 

 the second from Australia where the variety was undoubtedly intro- 

 duced. The present American sorgo varieties originated from these 

 17 introductions and a 1951 introduction from Ethiopia. 



The first grain sorghums grown in the United States were 

 White and Brown Durras which reached California from Egypt in 

 1874. These two varieties were never widely grown outside Cali- 

 fornia and have been unimportant as parents of present-day vari- 

 eties and hybrids. The progenitor of the milo varieties was intro- 

 duced into South America and reached South Carolina from Colum- 



