140 EXPERIMENT STATION RECORD. [Vol.40 



States; soil and climatic adaptations; field practices apd cultural methods em- 

 ployed in growing sugar beets ; irrigation, drainage, and seepage on sugar-beet 

 lands; the maintenance of soil fertility in sugar-beet production; crop rota- 

 tions for sugar beets and crops competing with sugar beets; farm equipment, 

 including live stock and labor; sugar-beet by-products and live-stock produc- 

 tion; labor problems; the successful grower; diseases and insects affecting the 

 crop ; roads ; contracts between growers and sugar companies ; competition be- 

 tween adjacent sugar-beet areas; and sugar-beet seed production. 



The inheritance of glume length in Triticum polonicum, a case of zygotic 

 inhibition, W. O. BACKHOUSE (Jour. Oenetica, 7 (1918), Wo. 2, pp. 125-188, fin*. 

 5). — Investigations begun in 1912 are described in which a variety of T. poloni- 

 cum, with an average glume length of 29 mm. (about 1.1 in.) and with glumes 

 very faintly pubescent (classed as smooth in comparison with Rivet or Essex 

 Rough Chaff), was crossed with a variety of T. durum, referred to as Kuhanka, 

 with an average glume length of 12 mm., quite smooth, and otherwise a typical 

 example of the species. The studies were suggested by observations made by 

 the author at Verrieres in 1911 of a collection of varieties of T. polonicum 

 grown there, which revealed the fact that none possessed perfectly smooth 

 glumes and that the shorter the glume the greater the pubescence appeared 

 to be. 



The Fi generation of the cross Doted above possessed glumes of interme- 

 diate lengths, I s or 19 mm., but was distinctly pubescent, while the i" 3 genera- 

 tion showed a certain proportion of plants bearing fully pubescenl ears. At 

 harvest times a middle glume in the ear of each plant was measured, and a 

 curve plotted in millimeters of a number of plants of each glume length. The 

 plants were also classified by means of a hand lens into pubescent, Intermediate, 

 and smooth, the T. polonicum parent falling in the intermediate class. A 

 large number of plants carried into the F» generation showed that, while only 

 two errors were made at the short end of the curves, it was Impossible to pick 



out any hut the extreme longs With a certainty that they would l»r 1 true 



to their particular length. The numbers observed were 172 long and Inter- 

 mediate and 55 short. Regarding those individuals with a glume length vary- 

 ing between 10 and 14 mm. ns pure short segregates and those between in 

 and 31 mm. r.s both the longs and the heterozygotes, a count of the proportion 

 of pubescent individuals showed for the short-glumed class i" pubescent to 15 

 smooth individuals, while an examination of 56 theoretical homozygous lot 

 revealed no individuals that could be classed as felted, although a short vel- 

 vety pubescence was to be seen with a lens. Among individuals with glume 

 lengths between 1. r > and 22 mm., the proportion was 85 felted to 31 smooth, 

 although only 15 individuals were distinctly pubescent 



Absolutely glabrous long-glumed individuals were carefully selected and 

 planted, and with two exceptions were found to be pure longs and also io 

 breed true to smoothness. In crosses between these smooth lines and the 

 original Kubanka to ascertain whether the presence of pubescence in any way 

 affected the segregation of glume length, the F 2 generation contained some 

 all-smooth individuals, the remainder behaving like the original cross and 

 giving a 3:1 proportion of felted and smooth ears among the short-glumed 

 class, the difference being only in the degree of pubescence, as exemplified in 

 Prelude. This is held to indicate " that the long glume was able to Inhibit 

 the expression of a dominant character [pubescence], and. furthermore, 

 that there was q direct relation between the length of the glume and the 

 degree of felting." 



