PRODUCING BREAD MAKING 



WHEATS FOR WARM CLIMATES' 



Introducing the Better Bread Making Quality of Soft Wheat Glutens into 



the Gluten of Macaroni Wheats — The Opaque Grain Indicates 



Insufficient Gluten, Translucent Grain an Abundance 



of It — Microscopic Sections an Aid 



in Breeding. 



George F. Freeman 



Department of Plant Breeding, University of Arizona, Agricultural Experiment 



Station, Tucson, Ariz. 



ECONOMIC wheat breeding al- 

 ways has for its aim the im- 

 provement of either the yield 

 or the quality of grain or per- 

 haps both. These objects are sought 

 through many contributing sub-charac- 

 ters such as drought or disease resist- 

 ance, stiffness of straw, time of ma- 

 turity, texture of grain, size of berry, 

 chemical composition, etc. As a char- 

 acter indicative of quality, the texture 

 of the grain is usually considered 

 important. A soft opaque texture is 

 generally recognized as being associated 

 with a low protein content whereas a 

 horny translucent grain is characteristic 

 of highly glutinous wheats. While 

 quality, as well as quantity, of gluten 

 ultimately determines the milling and 

 baking value of a wheat, high gluten 

 content is usually associated with the 

 ])roduction of the best grades of flour. 

 W'liereas the writer has shown' that 

 there are varieties of bread wheats 

 which will maintain their hard horny 

 texture in a warm irrigated district, 

 the low yield of these strains when 

 compared with the softer sorts, soon 

 results in the elimination of the former 

 group in any mixture where l)oth are 

 ])resent, as is the case with practically 

 all commercial planting. The result is 

 that so nearly all of the wheat pro- 

 duced in warm, humid regions is soft 

 in texture and of low gluten content 

 that the public have come to believe 

 that only soft wheat of inferior grade 

 can be grown in such a region. ^^Tleat 

 breeders in such countries are, there- 



' Freeman, Geo. F., 1917. A mechanical ex 

 of hard and soft wheat kernels. Joiini. Ainer. 



lore, concerned with the production of 

 varieties which are able to resist this 

 softening tendency of the warm cli- 

 mate, and which are, at the same time, 

 good yielders. It has also been shown 

 (1. c), that certain varieties of maca- 

 roni wheats remain hard when grown 

 by irrigation in southern Arizona, and 

 that, among these, those strains which 

 maintained their hardness were the best 

 yielders. Moreover, when these high 

 yielding macaroni wheats were com- 

 pared with the best producers among 

 the soft bread wheats, they were found 

 to be fully their equal. Macaroni 

 wheats are not popular for bread mak- 

 ing purposes on account of the fact 

 that the loaf is not so large or light 

 as that made from the bread wheats. 

 Now it was conceived some years 

 ago that the bread-making quality of 

 the high yielding soft wheats might be 

 introduced into the gluten of the 

 equally high yielding hard macaroni 

 wheats, and result in the production of 

 a high grade milling wheat for warm 

 climates. 



GOOD MII.LIXC. wheat FOR WARM 



climates 

 Accordingly, in 1913. reciprocal 

 crosses were made between a white 

 macaroni wheat ( No. 1 ) coming origi- 

 nally from Algeria, a soft red bread 

 wheat ( No. 3 ) also imported from 

 Algeria, and Sonora (No. 35), a soft 

 white wheat commonly grown locally. 

 I'he present ]:)aper gives the results of 

 a study of the inheritance of grain 

 texture through four generations of 



planation of the progressive change of proportion 

 Soc. Agron., Vol. x, No. 1 (1918), p. 23. 



211 



