UNITED STATES DEPARTMENT OF AGRICULTURE

In Cooperation with the

Montana Agricultural Experiment Station

DEPARTMENT BULLETIN No. 1403

Washington, D. C.

May, 1926

SEGREGATION AND CORRELATED INHERITANCE IN MARQUIS AND HARD FEDERATION CROSSES, WITH FACTORS FOR YIELD AND QUALITY OF SPRING WHEAT IN MONTANA

By J. ALLEN CLARK, Agronomist in Charge, and JOHN R. HOOKER, Scientific Aid, Western Wheat Investigations, Office of Cereal Crops and Diseases, Bureau of Plant Industry 1 1

LARGER YIELDS OF WHEAT WITH PRESENT QUALITY DESIRED

The profitable production of hard red spring wheat on the dry lands of Montana is dependent in part upon improvement in yield of the varieties grown. At present Marquis is the leading commercial spring wheat of the State. Under favorable conditions it is a highyielding variety, but under conditions of deficient moisture Marquis is not adapted sufficiently to produce profitable crops. In unfavorable seasons and in large sections having limited rainfall, therefore, spring-wheat production often is unprofitable in Montana, partly because of dependence on this or any other available variety.

The quality of Marquis is satisfactory. The low-yielding Marquis grown on the Montana dry lands is especially high in quality and much desired by the grain trade. The problem is therefore to

The Montana Agricultural Experiment Station cooperated in these investigations. Acknowledgment is gladly given here for field assistance rendered by M. A. Bell at Bozeman (1923) and Havre (1924), R. W. May at Moccasin, and J. L. Carter at Bozeman (1924). The writers also wish to express appreciation to Bewall Wright, of the Bureau of Animal Industry, United States Department of Agriculture, for advice given in the genetic and statistical analysis of the data.

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improve the yield and maintain the quality. In order to do this it is necessary to determine the factors which make for yield and quality under different Montana conditions and to develop a new variety of equal quality which will increase average yields.

MATERIAL AND METHODS

Unfavorable results with wheat production in Montana are almost entirely the result of drought. A new variety must be drought escaping or drought resistant in order to meet most successfully the prevailing conditions. The choice of an early drought-resistant high-yielding variety for crossing with Marquis and the selection of representative locations for testing the progeny in Montana were the problems of first consideration in developing a breeding program.

PARENT MATERIAL

The Hard Federation was selected for crossing with Marquis, as it appeared the best available variety at the time this study was projected. It had been included in varietal experiments at Moccasin, Mont., in 1920, and had outyielded Marquis by 7.7 bushels per acre. Its earliness, drought resistance, and high-yielding ability had been observed in Oregon and California and reported by Clark, Stephens, and Florell (6). The crosses were made in 1921, in which year Hard Federation was first included in varietal experiments at Bozeman and Havre, Mont., and at numerous stations in other States.

Marquis and Hard Federation have several contrasting morphological and quantitative characters, some of which affect differently their adaptation in certain localities and seasons. Marquis is a midseason, midtall variety with awnletted spikes, flat leaves, white glumes, and hard red kernels. Hard Federation is an early, short variety with awnless spikes, curling leaves, brown glumes, and hard white kernels. The inheritance of these contrasting characters and their effect, if any, on the yield and quality of the product under different Montana conditions have been studied.

Crude-protein content has been selected among several quality factors as the one most important, as it is directly reflected in the price of wheat when marketed. At present a premium is paid for hard red spring wheat of 5 to 10 cents a bushel for each per cent of crude protein above 12. Other quality factors are important but are more difficult to measure in the small quantity of seed available in hybrid material.

To show the comparative quality of the two parents, data from milling and baking experiments which have been conducted by the United States Department of Agriculture with comparable samples of Hard Federation and Marquis wheats during the seven years from 1918 to 1924, inclusive, are given in Table 1. The data show that Hard Federation compares favorably with Marquis in all factors. This result agrees with that of earlier experiments reported by Shollenberger and Clark (17), which show Hard Federation to be one of the best varieties for bread making in the white class. It has no important objectionable feature when compared with Marquis, recognized as the leading variety for milling and bread making.

2 The serial numbers (italic) in parentheses refer to "Literature cited" at the end of this bulletin.

TABLE 1.-Summary of milling and baking data from 69 comparable samples of Hard Federation and Marquis wheats grown during the seven years from 1918 to 1924, inclusive 1

1 Experiments conducted by the Milling Investigations Section, Grain Division, Bureau of Agricultural Economics.

Nx5.7; basis, 13.5 per cent moisture. 'Only 68 samples.

Since 1920 numerous agronomic data also have been accumulated which afford a basis for comparing the parental varieties. The data for six quantitative characters concerned in this inheritance study, from varietal experiments in plats at Bozeman, Moccasin, and Havre, Mont., are given in Table 2.

The data in Table 2 show that Hard Federation heads at a considerably earlier date than Marquis under all three environmental conditions and that it ripens but slightly earlier and sometimes as late or later. This results in a fruiting period, or number of days from heading to ripening, longer for Hard Federation than for Marquis. The length of the fruiting period also varies with the season, and the season producing the longer fruiting period appears to be associated with higher yield. Marquis is shown to be considerably taller (pl. 1) than Hard Federation, and greater height within each variety seems. to be directly associated with larger yields.

That comparative yields of the two varieties differ greatly in certain seasons may be due in part to the opposing advantages of a long fruiting period and of the growth factors which develop plant height. On the average, Hard Federation has slightly outyielded Marquis at Bozeman and Moccasin, but not at Havre. However, the lower vields of Hard Federation under the unfavorable conditions at Havre seem to be due more to damage from weeds (Russian thistles) than to its earliness or lack of drought resistance. The short stems

and curling leaves of Hard Federation render it less adapted than Marquis to compete with weed growth. In the nursery at Havre, where weed growth was destroyed, Hard Federation produced the higher yields.

The crude-protein content of the two varieties also differs greatly in certain seasons, with Marquis on the average exceeding Hard Federation at two of the three stations. High crude-protein content appears to be somewhat associated with low yields.

Correlation studies of these various factors in the progeny of hybrids of the two varieties will more definitely determine the amount

of association. Through the testing of large numbers of selections made on the basis of these correlations it is hoped to develop a new variety better adapted than either parent to Montana conditions.

TABLE 2.-Annual and average date of heading and ripening, fruiting period, height, yield, and crude-protein content of Marquis and Hard Federation wheats grown in plat experiments at Bozeman, Moccasin, and Havre, Mont., during the five years from 1920 to 1924, inclusive

Under a cooperative agreement with the Montana Agricultural Experiment Station the hybrid material was grown at the three stations previously mentioned, these stations being fairly representative of nonirrigated conditions in both the intermountain and Plains sections for wheat production in Montana.

Bozeman is located under fairly humid conditions in the Gallatin Valley and has a normal annual precipitation of 18.67 inches. Moc