data, corrected on the basis of F, results, also gave a close fit to that A 2-factor genetic interpretation of the results was made on the basis of primary (A, a) and secondary (B, b) factor pairs.

Brown glumes were dominant to white, and in the F, generation the deviations in numbers were not significantly different from the simple 3:1 ratio in any of the 12 F, families or in the several totals. In the F, generation the white-glumed plants all bred true and the brown-glumed plants either bred true or segregated in a 3:1 ratio in proportions which approximated the ratio of 1:2.

Red kernels were dominant to white, and in the F, generation 10 of the 12 F, families segregated in numbers close to a 2-factor 15:1 ratio and the two other families close to the single factor 3:1 ratio. In the F, studies of the 2-factor families the white-kerneled strains all bred true and the red-kerneled strains bred true or segregated in 3:1 or 15:1 ratios in proportions approximating a 7:4:4 ratio.

Maturity studies were made from the dates of heading, dates of ripening, and the days between these dates or from the heading, ripening, and fruiting periods.

In F2 early heading was partially dominant, although there were no large early and no small late groups. The hybrids were significantly more variable than the parents. No earlier heading strains than Hard Federation were produced, but transgressive segregation for lateness of heading was found, as F, strains were obtained which were significantly later in heading than Marquis both at Bozeman and Havre.

The time of ripening of the hybrids was nearly intermediate between the parents and not significantly more variable. Strains as uniform as the parents for the ripening period were obtained in the F generation, some of which were as late or later in ripening than the Marquis parent.

The average fruiting period of the hybrids was intermediate to those of the parents. Strains of short and long fruiting periods were observed which differed on the average by as much as 6.7 days at Bozeman and 8.1 days at Havre. One F, strain was obtained which was significantly shorter than that of Marquis at both stations, but no hybrids were found to have a longer fruiting period than that of Hard Federation.

2

From F, and F, studies, all gradations between the parents were found in average height without significantly greater variability than in the parents. The respective heights of the parents have been approximately reached by F, strains but not exceeded significantly.

3

Yields of F, plants on the average exceeded those of both parents at Bozeman but were less variable. Plant yields were studied in the F, generation at Bozeman where Marquis was the highest yielding parent and at Havre where Hard Federation was the highest yielding parent. From a high-yielding F, plant an F, strain was studied which significantly outyielded both the Marquis at Bozeman and the Hard Federation at Havre.

2

2

The crude-protein content of grain from F, plants was found intermediate between that of the parents and not significantly more variable. F, strains from the highest F2 plants did not rank among the best crude-protein strains at Bozeman or Havre. High crudeprotein F, strains were found less variable than low crude-protein strains. While strains of lower crude-protein content than Hard

3

Federation were obtained, no F, strain was studied which exceeded, although several practically equaled, Marquis in crude-protein con

tent.

The product of average yield per plant and crude-protein content was used to measure the amount of improvement made over the parents. The six leading strains at Bozeman, Moccasin, and Havre exceeded the best Marquis check rows from 1.5 to 81.8 per cent. This improvement in yield × crude-protein content apparently was obtained by combining the advantages of the long fruiting period of Hard Federation and the height of Marquis.

The amount of correlation was determined between all of the six quantitative characters-heading period, ripening period, fruiting period, height, yield, and crude-protein content at Bozeman, Moccasin, and Havre. The amount of correlated inheritance was found for each character in the F, and F, generations at Bozeman, and also in the F2 generation at Bozeman with the F3 generation at Havre.

2

3

Important and significant negative correlations were obtained between heading period and fruiting period and large positive correlations between ripening period and fruiting period.

The longer fruiting period and greater height were the most important factors positively correlated with larger yields.

Fruiting period, height, and yield were, on the average, all negatively correlated with crude-protein content.

3

Correlation between F2 plants and F, strains, indicative of inheritance, were obtained in important significant amounts at Bozeman for heading period, height, and yield and at Moccasin for height and yield. Only one character, heading period, was inherited in a significant amount in F, strains at Havre in 1924 from their F2 parent plants raised at Bozeman in 1923.

It is expected to develop, through the further testing of selections made on the basis of these studies, a new variety better adapted to Montana conditions than either Hard Federation or Marquis.

(1) BEAVEN, E. S.

LITERATURE CITED

1920. Breeding cereals for increased production. In Jour. Farmers' Club [London], pt. 6, pp. 107–121.

(2) BIFFEN, R. H.

1905. Mendel's laws of inheritance and wheat breeding. In Jour. Agr. Sci., vol. 1, pp. 4-48, illus.

(3) BRYAN, W. E., and E. H. PRESSLEY.

1921.

Plant breeding. In Ariz. Agr. Exp. Sta. Ann. Rpt. 32, pp. 601-605, illus.

(4) CARLETON, M. A.

1916. The Small Grains. 699 pp., illus. New York.

(5) CLARK, J. A.

1925. Segregation and correlated inheritance in crosses between Kota and Hard Federation wheats for rust and drought resistance. In Jour. Agr. Research, vol. 29 (1924), pp. 1-47, illus.

D. E. STEPHENS, and V. H. FLORELL.

(6)

1920.

Australian wheat varieties in the Pacific coast area. U. S.
Dept. Agr. Bul. 877, 25 pp., illus.

(7) FARRER, W.

1898. The making and improvement of wheats for Australian conditions. In Agr. Gaz. N. S. Wales, vol. 9, pp. 131-168, 241-260, illus.

(8) FLORELL, V. H.

(9)

1923.

Cereal experiments at Chico, Calif. U. S. Dept. Agr. Bul. 1172, 33 pp., illus.

1925. Studies on the inheritance of earliness in wheat. In Jour. Agr. Research, vol. 29 (1924), pp. 333-347, illus.

(10) FREEMAN, G. F.

1918. Producing bread-making wheats for warm climates. In Jour. Heredity, vol. 9, pp. 211-226, illus.

(11) HOWARD, A., and G. L. C. HOWARD.

1912-1915.

(12) LYON, T. L.

1905.

On the inheritance of some characters in wheat. I-II. In Mem. Dept. Agr. India, Bot. Ser., vol. 5, pp. 1-46 illus., 1912; vol. 7, pp. 273-285, illus., 1915.

Improving the quality of wheat. U. S. Dept. Agr., Bur. Plant
Indus., Bul. 78, 120 pp.

(13) NILSSON-EHLE, H.

1911. Kreuzungsuntersuchungen an Hafer und Weizen. II. Lunds Univ. Årsskr., n. F., Afd. 2, Bd. 7, no. 6, 82 pp.

(14) PEARSON, K.

1914. Tables for Statisticians and Biometricians. 143 pp., illus Cambridge.

(15) ROBERTS, H. F.

1919. Yellow-berry in hard winter wheat. In Jour. Aga Research, vol. 18, pp. 155-169, illus.

(16) SCHINDLER, F.

1893.

Der Weizen in seinen Beziehungen zum Klima und das Gesetz der Korrelation. 175 pp., illus. Berlin.

(17) SHOLLENBERGER, J. H., and J. A. CLARK.

1924. Milling and baking experiments with American wheat varieties. U. S. Dept. Agr. Bul. 1183, 92 pp., illus.

(18) THATCHER, R. W. 1913.

The chemical composition of wheat.
111, 79 pp., illus.

(19) THOMPSON, W. P.

Wash. Agr. Exp. Sta. Bul.

1918. The inheritance of the length of the flowering and ripening In Trans. Roy. Soc. Canada, ser. 3, vol. 12,

periods in wheat.
sect. 4, pp. 69-87.

(20) WALDRON, L. R. 1924.

A study of dwarfness in wheat accompanied by unexpected ratios. In Genetics, vol. 9, pp. 212-246, illus.

ORGANIZATION OF THE

UNITED STATES DEPARTMENT OF AGRICULTURE

April 24, 1926