1917] FIELD CROPS. 737 



Barres field beet now recognized in Denmark is briefly traced, and five strains, 

 known as Nsesgaard, Sludstrup, Rested, Ferritslev, and Lille Taar0je, are de- 

 scribed In detail with reference to form, color, top, ease of lifting, yield, dry 

 matter content, and uniformity. 



Genetical studies of variegated pericarp in maize, R. A. Emekson {Genetics, 

 2 {1911), No. 1, pp. 1-35, figs. 4).— This paper continues the study (E. S. R., 

 29, p. 333; 31, p. 135) of the inheritance of self-pattern in the pericarp of 

 maize seeds, occurring as a sporophytic variation in variegated ears. 



The later studies are in entire accord with those previously reported. The 

 author formerly termed these changes somatic variations because they were 

 first manifested in somatic cells. It was apparent from the beginning, however, 

 that the factorial modification responsible for the visible change must often 

 occur in meristematic cells from which later arise the germ cells as well as 

 the somatic tissues of the pericarp, or even of the whole ear, and since such 

 meristematic cells are germinal rather than somatic the variation is deemed to 

 be better termed sporophytic. 



Distinct variations in variegated ears of maize are described and new phases 

 of the problem reported on. Most of the data presented were obtained in 

 connection with heredity studies conducted at the Nebraska Experiment Station. 

 The points studied were inheritance of sporophytic mutations from variegation 

 to self-color, changes in type of variegation, reverse mutation — self-color to 

 variegation, suggested explanation of the inheritance of certain sporophytic 

 variations and the noninheritance of others, and the relation of variegation to 

 unit-factor constancy. 



" The seed ears used in the later studies have all been pollinated by colorless 

 strains to avoid difficulties arising from the uncertainty of the purity of the 

 pollen of variegated races. Self-colored, partly self-colored, variously varie- 

 gated, and colorless seeds from variegated parent ears, thus pollinated, have 

 given progenies containing a percentage of self-colored ears roughly propor- 

 tional to the amount of self-color in the seeds planted, the maximum being 

 approximately 50 per cent from self-colored and near-self seeds and the mini- 

 u]um none from colorless seeds. This has been equally true whether the parent 

 ears have been homozygous or heterozygous for pericarp color. In the latter 

 case, the self-colored ears have always occurred at the expense of variegated 

 ears, never at the expense of colorless ones. Medium variegation has been 

 found to be a simple Mendelian dominant to very light variegation. Self- 

 colored ears appearing in the progeny of Fi ears of this cross have occurred at 

 the expense of medium variegated ears rather than in the place of very light 

 variegated ones. These facts are held to indicate that a genetical factor for 

 variegation mutates to a factor for self-color, that only one of the duplex 

 factors ordinarily so mutates, and that the factor for medium variegation 

 mutates much more frequently than that for very light variegation." 



The results obtained indicate that there is an inheritance of a light type of 

 variegation arising as a sporophytic variation on medium variegated ears, 

 although this has not been fully investigated. A sporophytic change in the 

 type of variegation resulting in seeds with strongly colored crown spots asso- 

 ciated with self-colored cob glumes is not inherited as regards either pericarp 

 or glume color. 



From one to five wholly or partly variegated .seeds per ear have occurred on 

 about two-thirds of the self-colored ears descended from two presumably unre- 

 lated variegated ears. Other related and unrelated cultures have not exhibited 

 such exceptional seeds, and no variegated seeds, as far as known, ever occurred 

 on a homozygous self-colored ear. One test indicates the inheritance of these 

 presumably reverse mutations from self-color to variegation. 



